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Oracle 11g XE Delay?

with one comment

Somebody posted a comment inquiring about the release of Oracle 11g XE. They felt it had been delayed. As far as I know, the last word on that came from Andy Mendelsohn last October, as published in this InfoWorld article.

The Oracle Database 11g XE is released and the download link is here.

When Andy Mendelsohn originally announced Oracle 11g XE in an interview with the NY Times, he clearly said it would be based on the terminal release of Oracle 11g. I also suspect it’ll include APEX 4.0, which was recently released. Maybe we’ll see the release at or near Oracle Open World 2010.

I don’t endorse the negative remarks in the InfoWorld article about why Oracle 11g XE isn’t released. While I have no direct knowledge of the forthcoming release, I think there’s an alternative explanation for any delay. Based on my involvement with the Oracle 10g XE release, I believe Oracle wants a rock solid starter version. At least, that was a major concern when they released Oracle 10g XE.

Written by maclochlainn

June 28th, 2010 at 1:42 pm

Posted in Oracle,Oracle APEX,Oracle XE

Correlated Update Statement

without comments

My students wanted some additional examples on correlated update statements. I’ve been struggling with what the right way may be to illustrate them.

Correlated subqueries are a hard concept to explain to those new to SQL. While correlated update statements seem impossibly obscure to many or inordinately complex. New SQL developers often flee to the comfort of procedural programs when it comes to update statements.

This uses my video store data model. It’s a correlated update statement to clean up potential corrupt data. More or less something a DBA might run to ensure a business rule hasn’t been violated over time. It checks for the correct foreign key value in a table when a dependent table contains one or more than one row of data.

The aqua-green box highlights a subquery that aggregates foreign key columns and groups the result with the foreign key value. The results from this subquery become a run-time view or derived table. The result set is a foreign key value and a substitute string literal value for each row in the contact table. These results correlate to the update statement’s rows based on the input parameter. The input parameter is a column from each updated row.

A unique key (or check constraint) exists on the combination of the common_lookup_table, common_lookup_column, and common_lookup_type columns. This ensures that only one row is returned and assigned to the member_type column in the member table. The update statement naturally works in either Oracle or MySQL without any porting changes.

Correlated Update Statement ↓

Expand this section to see the clear text for the foregoing image.

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UPDATE member m
SET    member_type =
 (SELECT common_lookup_id
  FROM   common_lookup
  WHERE  common_lookup_table = 'MEMBER'
  AND    common_lookup_column = 'MEMBER_TYPE'           
  AND    common_lookup_type =
          (SELECT  dt.member_type
           FROM   (SELECT   c.member_id
                   ,        CASE
                              WHEN COUNT(c.member_id) > 1 THEN 'GROUP'
                              ELSE 'INDIVIDUAL'
                            END AS member_type
                   FROM     contact c
                   GROUP BY c.member_id) dt
           WHERE   dt.member_id = m.member_id));

While this type of solution is powerful in its own right, I thought it might be interesting to see their procedural equivalents. These correlated subqueries run for each row returned by the master query (or outermost statement). Therefore, they act like functions.

Procedural equivalents (or user-defined functions) simplify the update statement like so:

UPDATE member m
SET    member_type = get_member_type(m.member_id);

If you’re interested in seeing how you would implement this solution in a user-defined function, just expand the dropdown that interest you.

Oracle User-Defined Function (UDF) ↓

Expand this section to see how to map this logic to a PL/SQL schema-level function.

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CREATE OR REPLACE FUNCTION get_member_type
(pv_member_id NUMBER) RETURN NUMBER IS
 
  -- Define a collection of strings.
  TYPE type_options IS TABLE OF VARCHAR2(10);
 
  -- Declare local variables.
  lv_dependent NUMBER := 1;
  lv_return_id NUMBER;
 
  -- Declare a local variable of the collection.
  lv_member_type TYPE_OPTIONS := type_options('INDIVIDUAL','GROUP');
 
  -- Define a dynamic cursor to count the number of foreign key values. 
  CURSOR count_contact (cv_member_id NUMBER) IS
    SELECT COUNT(c.member_id)
    FROM   contact c
    WHERE  c.member_id = cv_member_id;
 
  -- Define a dynamic cursor to find a key for an individual or group member type.    
  CURSOR get_lookup_id (cv_type VARCHAR2) IS
    SELECT common_lookup_id
    FROM   common_lookup
    WHERE  common_lookup_context = 'MEMBER'
    AND    common_lookup_type = cv_type;
 
BEGIN
 
  -- Get the number of foreign key values for a contact.
  OPEN  count_contact(pv_member_id);
  FETCH count_contact
  INTO  lv_dependent;
  CLOSE count_contact;
 
  -- Open the dynamic cursor with the required value.  
  IF lv_dependent = 1 THEN
    OPEN get_lookup_id(lv_member_type(1));
  ELSE
    OPEN get_lookup_id(lv_member_type(2));
  END IF;
 
  -- Get the correct surrogate primary key value.
  FETCH get_lookup_id
  INTO  lv_return_id;
  CLOSE get_lookup_id;
 
  -- Return the correct primary key for use as a foreign key.
  RETURN lv_return_id;
END;
/

MySQL User-Defined Function (UDF) ↓

Expand this section to see how to map this logic to a Persistent Stored Module (PSM) function.

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SELECT 'DROP FUNCTION IF EXISTS get_member_type' AS "Statement";
DROP FUNCTION IF EXISTS get_member_type;
 
SELECT 'DELIMITER $$' AS "Statement";
DELIMITER $$
 
SELECT 'CREATE FUNCTION get_member_type' AS "Statement"$$
CREATE FUNCTION get_member_type(pv_member_id INT) RETURNS INT 
BEGIN
 
  /* Define three local variables. */
  DECLARE lv_contact_number  INT;
  DECLARE lv_member_type     CHAR(30);
  DECLARE lv_return_value    INT;
 
  /* Define a dynamic cursor to count the number of foreign key values. */  
  DECLARE contact_cursor CURSOR FOR
    SELECT COUNT(c.member_id)
    FROM   contact c
    WHERE  c.member_id = pv_member_id;
 
  /* Define a dynamic cursor to find a key for an individual or group member type. */
  DECLARE common_lookup_cursor CURSOR FOR
    SELECT common_lookup_id
    FROM   common_lookup
    WHERE  common_lookup_table = 'MEMBER'
    AND    common_lookup_column = 'MEMBER_TYPE'           
    AND    common_lookup_type = lv_member_type;
 
  /* Get the number of foreign key values for a contact. */    
  OPEN  contact_cursor;
  FETCH contact_cursor
  INTO  lv_contact_number;
  CLOSE contact_cursor;
 
  /* Assign group membership when more than one foreign key value is found; and
     assign individual membership when only one foreign key value is found. */  
  IF lv_contact_number > 1 THEN
    SET lv_member_type = 'GROUP';
  ELSE
    SET lv_member_type = 'INDIVIDUAL';
  END IF;
 
  /* Get the correct surrogate primary key value. */  
  OPEN  common_lookup_cursor;
  FETCH common_lookup_cursor
  INTO  lv_return_value;
  CLOSE common_lookup_cursor;
 
  /* Return the correct primary key for use as a foreign key. */  
  RETURN lv_return_value;
END;
$$
 
SELECT 'DELIMITER $$' AS "Statement"$$
DELIMITER ;

You can query the results of the update statement with the following.

Change Confirmation Query ↓

Expand this section to see the query that lets you examine the changes. It runs in either Oracle or MySQL without any changes.

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SELECT   m.member_id
,        dt.quantity
,        m.member_type
,        cl.common_lookup_type
FROM     member m JOIN (SELECT   member_id
                        ,        COUNT(c.member_id) AS quantity
                        FROM     contact c
                        GROUP BY c.member_id) dt
ON       m.member_id = dt.member_id JOIN common_lookup cl
ON       m.member_type = cl.common_lookup_id
ORDER BY m.member_id;

As always, I look forward to helping and gaining insight.

Written by maclochlainn

June 27th, 2010 at 10:12 pm

Posted in MySQL,Oracle,Oracle XE,Persistent Stored Modules,pl/sql,PSM,sql

Debugging MySQL Functions

with 4 comments

Somebody, who read this post on Debugging MySQL Procedures, asked why the strategy of selecting a string literal didn’t work in a MySQL function. That’s easy, they’re not designed to support a SELECT statement, only a SELECT-INTO statement.

Why? That’s the purpose of a function to perform something and return a single reply.

That’s also why a MySQL functions only support the IN mode of operation for formal and call parameters. When formal parameters are restricted to in-mode-only operations, they implement a pass-by-value function model. This can also be expressed from the other side of the looking glass. In that case, MySQL functions don’t support pass-by-reference functions that use the INOUT or OUT mode operations.

If you put a SELECT statement in a function to print internal values or comments, it raises an error. Take for example the following attempt to create the debugging function with an echo of output (that works in stored procedures).

CREATE FUNCTION debugger() RETURNS INT
BEGIN
  SELECT '[Debug #1]';
  RETURN 1;
END;
$$

It fails to create the function because you’ve violated a key integrity rule. It also raises the following error:

ERROR 1415 (0A000): Not allowed to return a result set from a function

You have two potential solutions to this problem. The first is limited and inflexible. The second isn’t as limited or inflexible and is the recommended way to debug your functions without a tool. That’s to use a temporary table to record run-time debugging events.

Session Variable Debugging ↓

Expand this section to see the steps for debugging functions with session variables.

  1. Create two session level variables, like these:
SET @counter := 0;
SET @msg := '';
  1. Create a function that uses the SELECT-INTO statement to collect and store debugging information during function execution.
CREATE FUNCTION debugger() RETURNS INT
BEGIN
  SELECT @counter + 1 INTO @counter;
  SELECT CONCAT('[Debug #',@counter,']') INTO @msg;
  RETURN 1;
END;
$$
  1. Run the function and then query the session variable for results
SELECT debugger();
SELECT @msg;

You’ll see the following text:

+------------+
| @msg       |
+------------+
| [Debug #1] |
+------------+

Temporary Table Debugging ↓

Expand this section to see the steps for debugging functions with session variables.

  1. Only when you want a counter, create one session level variables.
SET @counter := 0;
  1. Create an in-memory table to store debugging information from function execution.
CREATE TABLE debugger
( debug_comment CHAR(80)) ENGINE=MEMORY;
  1. Create a function that supports inserts into the in-memory table. Naturally, you may need to make the columns larger when your debugging results are large. I’ve found that 80 characters is generally adequate for most debugging exercises.
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CREATE FUNCTION debugger() RETURNS INT
BEGIN
  SELECT @counter + 1 INTO @counter;
  INSERT INTO debugger VALUES (CONCAT('[Debug #',@counter,']'));
  RETURN 1;
END;
$$
  1. Call the function and query the debugging results.
SELECT debugger();
SELECT debugger();
SELECT debugger();
SELECT debug_comment FROM debugger;

You’ll see the following text:

+---------------+
| debug_comment |
+---------------+
| [Debug #1]    |
| [Debug #2]    |
| [Debug #3]    |
+---------------+

Complete Code Sample ↓

Expand this section to see the sample working code for all examples.

This script creates, runs, and tests the code from the above discussions.

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-- Conditionally drop the function when it exists.
DROP FUNCTION IF EXISTS debugger;
 
-- Set delimiter to create a function with semicolon statment terminators.
DELIMITER $$
 
-- Create a function that returns 1.
CREATE FUNCTION debugger() RETURNS INT
BEGIN
  SELECT '[Debug #1]';
  RETURN 1;
END;
$$
 
-- Reset the delimiter to enable normal execution.
DELIMITER ;
 
-- Declare session level variables.
SET @counter := 0;
SET @msg := '';
 
-- Conditionally drop the function when it exists.
DROP FUNCTION IF EXISTS debugger;
 
-- Set delimiter to create a function with semicolon statment terminators.
DELIMITER $$
 
-- Create a function that writes to local session variables.
CREATE FUNCTION debugger() RETURNS INT
BEGIN
  SELECT @counter + 1 INTO @counter;
  SELECT CONCAT('[Debug #',@counter,']') INTO @msg;
  RETURN 1;
END;
$$
 
-- Reset the delimiter to enable normal execution.
DELIMITER ;
 
-- Test the function code and read the session-level variable contents.
SELECT debugger();
SELECT @msg;
 
-- Declare a session level variable.
SET @counter := 0;
 
-- Conditionally drop the function when it exists.
DROP TABLE IF EXISTS debugger;
 
-- Create a temporary (in-memory) table to record debugging information.
CREATE TABLE debugger
( debug_comment CHAR(80)) ENGINE=MEMORY;
 
-- Conditionally drop the function when it exists.
DROP FUNCTION IF EXISTS debugger;
 
-- Set delimiter to create a function with semicolon statment terminators.
DELIMITER $$
 
-- Create a function that writes to a debugging table.
CREATE FUNCTION debugger() RETURNS INT
BEGIN
  SELECT @counter + 1 INTO @counter;
  INSERT INTO debugger VALUES (CONCAT('[Debug #',@counter,']'));
  RETURN 1;
END;
$$
 
-- Reset the delimiter to enable normal execution.
DELIMITER ;
 
-- Test the function code and read the session-level variable contents.
SELECT debugger();
SELECT debugger();
SELECT debugger();
SELECT debug_comment FROM debugger;

Written by maclochlainn

June 26th, 2010 at 6:51 pm

Posted in MySQL,Persistent Stored Modules,pl/sql,PSM,sql,Stored Procedures

Tagged with ,

Show indexes in Oracle

with 2 comments

One of my students asked how you could show index from table_name; in Oracle. They were chagrined when I told them there wasn’t an equivalent command. Outside of using Quest’s Toad or Oracle SQL*Developer, you can query the data catalog, like so:

-- SQL*Plus formatting commands.
COLUMN index_name FORMAT A32
COLUMN column_position FORMAT 999 HEADING "COLUMN|POSITION"
COLUMN column_name FORMAT A32
 
-- Ordinary query with a substitution variable.
SELECT i.index_name
,      ic.column_position
,      ic.column_name
FROM   user_indexes i JOIN user_ind_columns ic
ON     i.index_name = ic.index_name
WHERE  i.table_name = UPPER('&input')

Naturally, this is a subset of what’s returned by the show index from table_name; syntax. There is much more information in these tables but I only wanted to show an example.

The UPPER function command ensures that the table name is found in the database. Unless you’ve created a case sensitive object, they’re stored in uppercase strings.

While a single SQL statement works well, a little organization in PL/SQL makes it more readable. A display_indexes function provides that organization. It only displays normal indexes, not LOB indexes, and it depends on a schema-level collection of strings. This is the user-defined type (UDT) that I used for the collection.

CREATE OR REPLACE TYPE index_table AS TABLE OF VARCHAR2(200);
/

The following is the definition of the function:

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CREATE OR REPLACE FUNCTION display_indexes
( pv_table_name VARCHAR2 ) RETURN INDEX_TABLE IS
 
  -- Declare an iterator for the collection return variable.
  index_counter  NUMBER := 1;
  column_counter NUMBER;
 
  -- Declare and initialize local collection variable as return type.
  index_desc INDEX_TABLE := index_table();
 
  -- Get indexes.
  CURSOR index_name (cv_table_name VARCHAR2) IS
    SELECT   i.index_name
    FROM     user_indexes i
    WHERE    i.table_name = cv_table_name
    AND      i.index_type = 'NORMAL'
    ORDER BY 1;
 
  -- Get index columns.    
  CURSOR index_columns (cv_index_name VARCHAR2) IS
    SELECT   ic.column_position
    ,        ic.column_name
    FROM     user_ind_columns ic
    WHERE    ic.index_name = cv_index_name
    ORDER BY 1;
 
BEGIN
 
  -- Assign the table name to the collection.
  index_desc.EXTEND;
  index_desc(index_counter) := UPPER(pv_table_name);
  index_counter := index_counter + 1;
 
  FOR i IN index_name(UPPER(pv_table_name)) LOOP
 
    -- Assign the index name to the collection.
    index_desc.EXTEND;
    index_desc(index_counter) := LPAD(i.index_name,2 + LENGTH(i.index_name),' ');
 
    -- Set column counter on entry to nested loop.
    column_counter := 1;
 
    FOR j IN index_columns(i.index_name) LOOP
 
      IF column_counter = 1 THEN
 
        -- Increment the column counter, extend space, and concatenate to string.
        column_counter := column_counter + 1;
        index_desc.EXTEND;
        index_desc(index_counter) := index_desc(index_counter) || '(' || LOWER(j.column_name);
 
      ELSE
 
        -- Add a subsequent column to the list.
        index_desc(index_counter) := index_desc(index_counter) || ',' || LOWER(j.column_name);
 
      END IF;
 
    END LOOP;
 
    -- Append a close parenthesis and incredment index counter.
    index_desc(index_counter) := index_desc(index_counter) || ')';
    index_counter := index_counter + 1;
 
  END LOOP;
 
  -- Return the array.
  RETURN index_desc;
END;
/

You can call the function with this syntax:

SELECT column_value AS "TRANSACTION INDEXES"
FROM   TABLE(display_indexes('TRANSACTION'));

It returns the following formatted output for the TRANSACTION table, which is much nicer than the SQL output. Unfortunately, it will take more effort to place it on par with the show index from table_name; in MySQL.

TRANSACTION INDEXES
------------------------------------------------------------------------------------------------------------------------------
TRANSACTION
  PK_TRANSACTION(transaction_id)
  UQ_TRANSACTION(rental_id,transaction_type,transaction_date,payment_method_type,payment_account_number,transaction_account)

As always, I hope it helps folks.

Written by maclochlainn

June 22nd, 2010 at 1:28 am

Posted in Oracle,Oracle XE,pl/sql,sql

MySQL Timestamp to Date?

with 3 comments

One of my ex-students asked for an example of converting a DATETIME column into a DATE data type in MySQL. He’d tried a few approaches and hadn’t been successful. It’s best to use the DATE function to convert a DATETIME to a DATE in MySQL.

  1. Create a sample TIMECLOCK table.
DROP TABLE IF EXISTS timeclock;
 
CREATE TABLE TIMECLOCK
( timeclock_id  INT UNSIGNED AUTO_INCREMENT PRIMARY KEY
, timein        datetime
, timeout       datetime);
  1. Insert two rows with values in the TIMEIN column.
-- Insert two rows with automatic numbering and only a "time in" value.
INSERT INTO timeclock
( timein )
VALUES
(NOW()),(NOW());
  1. Update the previously inserted rows with values in the TIMEOUT column. The first UPDATE statement inserts a UTC date into the DATETIME column. That date is a time stamp of of the next day at 12:00 A.M. in the morning. The second UPDATE statement updates the TIMEOUT column with a current time stamp plus 4 hours, thirty-two minutes, and thirty-three seconds. Then, the code segment queries the results.
-- Update with tomorrow's future date at 12:00 A.M..
UPDATE timeclock
SET    timeout = ADDDATE(DATE(NOW()), INTERVAL 1 DAY)
WHERE  timeclock_id = 1;
 
-- Update with a timestamp 4 hours, thirty-two minutes, and thirty-three seconds in the future.
UPDATE timeclock
SET    timeout = ADDTIME(NOW(), '4:32:33')
WHERE  timeclock_id = 2;
 
-- Query the value sets.
SELECT timein, timeout FROM timeclock;

This returns:

+---------------------+---------------------+
| timein              | timeout             |
+---------------------+---------------------+
| 2010-06-18 16:16:08 | 2010-06-19 00:00:00 |
| 2010-06-18 16:16:08 | 2010-06-18 20:48:42 |
+---------------------+---------------------+
2 rows in set (0.00 sec)
  1. Query the differences of the timestamps as dates and times. The DATE function lets you convert a DATETIME into a DATE data type. Then, the DATEDIFF calculates the difference and returns an integer result (the interval of days). You calculate the time difference by using the TIMEDIFF function.
-- Query the difference in intervals of days.
SELECT DATE(timeout) AS dateout
,      DATE(timein) AS datein
,      DATEDIFF(DATE(timeout),DATE(timein))
FROM timeclock;
 
-- Query the difference in intervals of time.
SELECT timeout
,      timein
,      TIMEDIFF(timeout,timein)
FROM   timeclock;

These return:

+------------+------------+--------------------------------------+
| dateout    | datein     | DATEDIFF(DATE(timeout),DATE(timein)) |
+------------+------------+--------------------------------------+
| 2010-06-19 | 2010-06-18 |                                    1 |
| 2010-06-18 | 2010-06-18 |                                    0 |
+------------+------------+--------------------------------------+
2 rows in set (0.00 sec)
 
+---------------------+---------------------+--------------------------+
| timeout             | timein              | TIMEDIFF(timeout,timein) |
+---------------------+---------------------+--------------------------+
| 2010-06-19 00:00:00 | 2010-06-18 16:16:08 | 07:43:52                 |
| 2010-06-18 20:48:42 | 2010-06-18 16:16:08 | 04:32:34                 |
+---------------------+---------------------+--------------------------+
2 rows in set (0.00 sec)

You can also use:

SELECT CAST(timein AS DATE)
,      CAST(timeout AS DATE)
FROM   timeclock;

Hope this helps the one who asked how and anybody else who runs across it.

Written by maclochlainn

June 18th, 2010 at 5:48 pm

Posted in MySQL,sql

A \G Option for Oracle?

with 7 comments

The \G option in MySQL lets you display rows of data as sets with the columns on the left and the data on the write. I figured it would be fun to write those for Oracle when somebody pointed out that they weren’t out there in cyberspace (first page of a Google search ;-)).

I started the program with a student’s code. I thought it a bit advanced for the student but didn’t check if he’d snagged it somewhere. Thanks to Niall Litchfield, I now know that the base code came from an earlier post of Tom Kyte. Tom’s example code failed when returning a Blob, BFile, or CFile column.

Naturally, there are two ways to write this. One is a procedure and the other is the function. This post contains both. The procedure is limited because of potential buffer overflows associated with the DBMS_OUTPUT package’s display. A function isn’t limited because you can return a collection from the function.

Required setup to use the DBMS_SQL package ↓

The DBMS_SQL package requires permissions. There are two ways to provide those permissions. One is more secure and sensible in a production system and the other is great in a development test system.

Production or Test System

If this is a production system, you probably want to grant permissions only to the SYSTEM schema. This follows the practice of narrowing access to powerful features and control systems.

The first step requires the SYS user to grant permissions and authority to re-grant to individual users. You connect as the privileged user, like:

sqlplus / AS sysdba

When connected as the SYS, you run the following two commands:

GRANT EXECUTE ON dbms_sys_sql TO system;
GRANT EXECUTE ON dbms_sql TO system;

You should then define the procedure or function as a CURRENT_USER module. This type of module is known as an invoker’s right program. The code is owned by the SYSTEM schema but you run it on your own objects in your less privileged schema.

You can do that by replacing the function and procedure headers with these:

CREATE OR REPLACE PROCEDURE display_vertical
( TABLE_NAME VARCHAR2, where_clause VARCHAR2 ) AUTHID CURRENT_USER IS
CREATE OR REPLACE FUNCTION vertical_query
( TABLE_NAME VARCHAR2, where_clause VARCHAR2 ) RETURN query_result
AUTHID CURRENT_USER IS

After you compile the procedure and function in the SYSTEM schema, you should grant access to a schema (more restricted) or public (as generic tools). You should also create synonyms. The following commands assume you want to deploy these as generic tools. As the SYSTEM user, it grants privileges and then creates public synonyms.

-- Grant privileges.
GRANT EXECUTE ON display_vertical TO PUBLIC;
GRANT EXECUTE ON vertical_query TO PUBLIC;
 
-- Create public synonyms.
CREATE PUBLIC SYNONYM display_vertical FOR system.display_vertical;
CREATE PUBLIC SYNONYM vertical_query FOR system.vertical_query;

You should now be able to call these from any schema to work with their own tables and views.

Student Development System

If this is a test system and you’re new to Oracle, the following should help you. This shows you how to implement these in a Definer’s right model, inside a STUDENT schema.

This isn’t a secure design, but it allows you to keep your testing limited to a STUDENT schema. When these permissions aren’t granted the examples won’t work at all.

The first step requires the SYS user to grant permissions and authority to re-grant to individual users. You connect as the privileged user, like:

sqlplus / AS sysdba

When connected as the SYS, you run the following two commands:

GRANT EXECUTE ON dbms_sys_sql TO system WITH GRANT OPTION;
GRANT EXECUTE ON dbms_sql TO system WITH GRANT OPTION;

You don’t have to exit to reconnect as the SYSTEM user. Just type the following at the SQL command prompt (substitute your password ;-)).

CONNECT system/password

When connected as the SYSTEM user, you run the following two commands:

GRANT EXECUTE ON dbms_sys_sql TO student;
GRANT EXECUTE ON dbms_sql TO student;

You should now be able to compile the function and procedure.

Procedure for \G output ↓

The procedure nice because there’s only a dependency on the buffer size for the DBMS_OUTPUT package. The procedure only returns column values that are printable at the console, and it only returns the first 40 characters of long text strings.

Here’s the procedure definition:

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-- Create procedure.
CREATE OR REPLACE PROCEDURE display_vertical
( TABLE_NAME VARCHAR2, where_clause VARCHAR2 ) IS
 
  -- Open a cursor for a query against all columns in a table. 
  base_stmt  INTEGER := dbms_sql.open_cursor;
 
  -- Open a cursor for a dynamically constructed query, which excludes
  -- any non-displayable columns with text.
  stmt  INTEGER := dbms_sql.open_cursor;
 
  -- Declare local variables.
  colValue   VARCHAR2(4000);      -- Declare a maximum string length for column values.
  STATUS     INTEGER;             -- Declare a variable to hold acknowledgement of DBMS_SQL.EXECUTE
  tableDesc  dbms_sql.desc_tab2;  -- Declare a table to hold metadata for the queries.
  colCount   NUMBER;              -- Declare a variable for the column count.
  rowIndex   NUMBER := 0;         -- for displaying the row number retrieved from the cursor
  colLength  NUMBER := 0;         -- for keeping track of the length of the longest column name
 
  -- Declare local variable for the dynamically constructed query.
  dynamic_stmt VARCHAR2(4000) := 'SELECT ';
 
  -- Declare an exception for a bad table name, raised by a call to
  -- the dbms_assert.qualified_sql_name function.
  table_name_error EXCEPTION;
  PRAGMA EXCEPTION_INIT(table_name_error, -942);
 
  -- Declare exception handlers for bad WHERE clause statements.
 
  -- Declare an exception for a missing WHERE keyword.
  missing_keyword EXCEPTION;
  PRAGMA EXCEPTION_INIT(missing_keyword, -933);  
 
  -- Declare an exception for a bad relational operator.
  invalid_relational_operator EXCEPTION;
  PRAGMA EXCEPTION_INIT(invalid_relational_operator, -920);  
 
  -- Declare an exception for a bad column name.
  invalid_identifier EXCEPTION;
  PRAGMA EXCEPTION_INIT(invalid_identifier, -904);  
 
  -- Declare an exception for a missing backquoted apostrophe.
  misquoted_string EXCEPTION;
  PRAGMA EXCEPTION_INIT(misquoted_string, -1756);  
 
  -- Declare a function that replaces non-displayable values with text messages.
  FUNCTION check_column( p_name   VARCHAR2
                       , p_type   NUMBER ) RETURN VARCHAR2 IS
 
    -- Return column name or literal value.
    retval VARCHAR2(30);			   
 
  BEGIN
 
    -- Find strings, numbers, dates, timestamps, rowids and replace non-display values.
    IF p_type IN (1,2,8,9,12,69,96,100,101,112,178,179,180,181,231) THEN
 
      -- Assign the column name for a displayable column value.
      retval := p_name;
 
    ELSE
 
      -- Re-assign string literals for column names where values aren't displayable.      
      SELECT DECODE(p_type, 23,'''RAW not displayable.'''
                          ,105,'''MLSLABEL not displayable.'''
                          ,106,'''MLSLABEL not displayable.'''
                          ,113,'''BLOB not displayable.'''
                          ,114,'''BFILE not displayable.'''
                          ,115,'''CFILE not displayable.'''
                          ,'''UNDEFINED not displayable.''')
      INTO retval
      FROM dual;
 
    END IF;
 
    -- Return the column name or a apostrophe delimited string literal.
    RETURN retval;
  END check_column;
 
BEGIN
 
  -- Prepare unfiltered display cursor.
  dbms_sql.parse(base_stmt, 'SELECT * FROM ' || dbms_assert.simple_sql_name(TABLE_NAME) || ' ' || where_clause, dbms_sql.native);
 
  -- Describe the table structure:
  -- --------------------------------------------------------
  --  1. Store metadata in tableDesc
  --  2. Store the number of columns in colCount
  -- --------------------------------------------------------
  dbms_sql.describe_columns2(base_stmt, colCount, tableDesc);
 
  -- Define individual columns and assign value to colValue variable.
  FOR i IN 1..colCount LOOP
 
    -- Define columns for each column returned into tableDesc.
    dbms_sql.define_column(base_stmt, i, colValue, 4000);
 
    -- Find the length of the longest column name.
    IF LENGTH(tableDesc(i).col_name) > colLength THEN
      colLength := LENGTH(tableDesc(i).col_name);
    END IF;
 
    -- Replace non-displayable column values with displayable values.
    IF i < colCount THEN
      dynamic_stmt := dynamic_stmt || check_column(tableDesc(i).col_name,tableDesc(i).col_type) || ' AS '
                   || tableDesc(i).col_name || ', ';
    ELSE
      dynamic_stmt := dynamic_stmt || check_column(tableDesc(i).col_name,tableDesc(i).col_type) || ' AS '
                   || tableDesc(i).col_name || ' ' || 'FROM ' || dbms_assert.simple_sql_name(TABLE_NAME)
                   || ' ' || where_clause;
    END IF;
 
  END LOOP;
 
  -- Provide conditional debugging instruction that displays dynamically created query.
  $IF $$DEBUG = 1 $THEN
     dbms_output.put_line(dynamic_stmt);
  $END
 
  -- Prepare unfiltered display cursor. 
  dbms_sql.parse(stmt, dynamic_stmt, dbms_sql.native);
 
  -- Describe the table structure:
  -- --------------------------------------------------------
  --  1. Store metadata in tableDesc (reuse of existing variable)
  --  2. Store the number of columns in colCount
  -- --------------------------------------------------------
  dbms_sql.describe_columns2(stmt, colCount, tableDesc);
 
  -- Define individual columns and assign value to colValue variable.
  FOR i IN 1..colCount LOOP
    dbms_sql.define_column(stmt, i, colValue, 4000);
  END LOOP;
 
  -- Execute the dynamic cursor.
  STATUS := dbms_sql.execute(stmt);
 
  -- Fetch the results, row-by-row.
  WHILE dbms_sql.fetch_rows(stmt) > 0 LOOP
 
    -- Reset row counter for display purposes.
    rowIndex := rowIndex + 1;
    dbms_output.put_line('********************************** ' || rowIndex || '. row **********************************');
 
    -- For each column, print left-aligned column names and values.
    FOR i IN 1..colCount LOOP
 
      -- Limit display of long text.  
      IF tableDesc(i).col_type IN (1,9,96,112) THEN
 
        -- Display 40 character substrings of long text.  
  	dbms_sql.column_value(stmt, i, colValue);
        dbms_output.put_line(RPAD(tableDesc(i).col_name, colLength,' ') || ' : ' || SUBSTR(colValue, 1,40));	  
 
      ELSE
 
        -- Display full value as character string.  
        dbms_sql.column_value(stmt, i, colValue);
        dbms_output.put_line(RPAD(tableDesc(i).col_name, colLength,' ') || ' : ' || colValue);
 
      END IF;
 
    END LOOP;
 
  END LOOP;
 
EXCEPTION
  -- Customer error handlers.
  WHEN table_name_error THEN
    dbms_output.put_line(SQLERRM);
  WHEN invalid_relational_operator THEN
    dbms_output.put_line(SQLERRM);
  WHEN invalid_identifier THEN
    dbms_output.put_line(SQLERRM);
  WHEN missing_keyword THEN
    dbms_output.put_line(SQLERRM);
  WHEN misquoted_string THEN
    dbms_output.put_line(SQLERRM);
  WHEN OTHERS THEN
    dbms_output.put_line(SQLERRM);
END;
/

You can run the procedure with the following syntax:

EXECUTE display_vertical('ITEM','WHERE item_title LIKE ''Star%''');

It’ll return the following display of data:

********************************** 1. ROW **********************************
ITEM_ID           : 1002
ITEM_BARCODE      : 24543-02392
ITEM_TYPE         : 1011
ITEM_TITLE        : Star Wars I
ITEM_SUBTITLE     : Phantom Menace
ITEM_RATING       : PG
ITEM_RELEASE_DATE : 04-MAY-99
CREATED_BY        : 3
CREATION_DATE     : 09-JUN-10
LAST_UPDATED_BY   : 3
LAST_UPDATE_DATE  : 09-JUN-10
ITEM_DESC         :
DISPLAY_PHOTO     : BLOB NOT displayable.
********************************** 2. ROW **********************************
ITEM_ID           : 1003
ITEM_BARCODE      : 24543-5615
ITEM_TYPE         : 1010
ITEM_TITLE        : Star Wars II
ITEM_SUBTITLE     : Attack OF the Clones
ITEM_RATING       : PG
ITEM_RELEASE_DATE : 16-MAY-02
CREATED_BY        : 3
CREATION_DATE     : 09-JUN-10
LAST_UPDATED_BY   : 3
LAST_UPDATE_DATE  : 09-JUN-10
ITEM_DESC         :
DISPLAY_PHOTO     : BLOB NOT displayable.
********************************** 3. ROW **********************************
ITEM_ID           : 1004
ITEM_BARCODE      : 24543-05539
ITEM_TYPE         : 1011
ITEM_TITLE        : Star Wars II
ITEM_SUBTITLE     : Attack OF the Clones
ITEM_RATING       : PG
ITEM_RELEASE_DATE : 16-MAY-02
CREATED_BY        : 3
CREATION_DATE     : 09-JUN-10
LAST_UPDATED_BY   : 3
LAST_UPDATE_DATE  : 09-JUN-10
ITEM_DESC         : This IS designed TO be a long enough str
DISPLAY_PHOTO     : BLOB NOT displayable.
********************************** 4. ROW **********************************
ITEM_ID           : 1005
ITEM_BARCODE      : 24543-20309
ITEM_TYPE         : 1011
ITEM_TITLE        : Star Wars III
ITEM_SUBTITLE     : Revenge OF the Sith
ITEM_RATING       : PG13
ITEM_RELEASE_DATE : 19-MAY-05
CREATED_BY        : 3
CREATION_DATE     : 09-JUN-10
LAST_UPDATED_BY   : 3
LAST_UPDATE_DATE  : 09-JUN-10
ITEM_DESC         :
DISPLAY_PHOTO     : BLOB NOT displayable.

Function for \G output ↓

The function is the best solution. It does have a dependency on a user-defined type (UDT). The function, like the procedure, only returns column values that are printable at the console. It also parses the first 40 characters from long text strings.

Before you create the function, you must create a UDT collection variable. The following syntax creates a schema-level UDT.

CREATE OR REPLACE TYPE query_result AS TABLE OF VARCHAR2(77);
/

Here’s the function definition:

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CREATE OR REPLACE FUNCTION vertical_query
( TABLE_NAME VARCHAR2, where_clause VARCHAR2 ) RETURN query_result IS
 
  -- Open a cursor for a query against all columns in a table. 
  base_stmt	INTEGER := dbms_sql.open_cursor;
 
  -- Open a cursor for a dynamically constructed query, which excludes
  -- any non-displayable columns with text.
  stmt      INTEGER := dbms_sql.open_cursor;
 
  -- Declare local variables.
  colValue	VARCHAR2(4000);      -- Declare a maximum string length for column values.
  STATUS		INTEGER;             -- Declare a variable to hold acknowledgement of DBMS_SQL.EXECUTE
  tableDesc	dbms_sql.desc_tab2;  -- Declare a table to hold metadata for the queries.
  colCount	NUMBER;              -- Declare a variable for the column count.
  rowIndex	NUMBER := 0;         -- for displaying the row number retrieved from the cursor
  colLength	NUMBER := 0;         -- for keeping track of the length of the longest column name
 
  -- Declare local variable for the dynamically constructed query.
  dynamic_stmt VARCHAR2(4000) := 'SELECT ';
 
  -- Declare a index for the return collection.
  rsIndex NUMBER := 0;
 
  -- Declare a collection variable and instantiate the collection.
  result_set QUERY_RESULT := query_result();
 
  -- Declare an exception for a bad table name, raised by a call to
  -- the dbms_assert.qualified_sql_name function.
  table_name_error EXCEPTION;
  PRAGMA EXCEPTION_INIT(table_name_error, -942);
 
  -- Declare exception handlers for bad WHERE clause statements.
 
  -- Declare an exception for a missing WHERE keyword.
  missing_keyword EXCEPTION;
  PRAGMA EXCEPTION_INIT(missing_keyword, -933);  
 
  -- Declare an exception for a bad relational operator.
  invalid_relational_operator EXCEPTION;
  PRAGMA EXCEPTION_INIT(invalid_relational_operator, -920);  
 
  -- Declare an exception for a bad column name.
  invalid_identifier EXCEPTION;
  PRAGMA EXCEPTION_INIT(invalid_identifier, -904);  
 
  -- Declare an exception for a missing backquoted apostrophe.
  misquoted_string EXCEPTION;
  PRAGMA EXCEPTION_INIT(misquoted_string, -1756);  
 
  -- ------------------------------------------------------------------
 
  -- Declare a function that replaces non-displayable values with text messages.
  FUNCTION check_column( p_name   VARCHAR2
                       , p_type   NUMBER ) RETURN VARCHAR2 IS
 
    -- Return column name or literal value.
    retval VARCHAR2(30);			   
 
  BEGIN
 
    -- Find strings, numbers, dates, timestamps, rowids and replace non-display values.
    IF p_type IN (1,2,8,9,12,69,96,100,101,112,178,179,180,181,231) THEN
 
      -- Assign the column name for a displayable column value.
      retval := p_name;
 
    ELSE
 
      -- Re-assign string literals for column names where values aren't displayable.      
      SELECT DECODE(p_type, 23,'''RAW not displayable.'''
                          ,105,'''MLSLABEL not displayable.'''
                          ,106,'''MLSLABEL not displayable.'''
                          ,113,'''BLOB not displayable.'''
                          ,114,'''BFILE not displayable.'''
                          ,115,'''CFILE not displayable.'''
                          ,'''UNDEFINED not displayable.''')
      INTO retval
      FROM dual;
 
    END IF;
 
    -- Return the column name or a apostrophe delimited string literal.
    RETURN retval;
  END check_column;
 
  -- ------------------------------------------------------------------
 
BEGIN
 
	-- Prepare unfiltered display cursor.
	dbms_sql.parse(base_stmt, 'SELECT * FROM ' || dbms_assert.simple_sql_name(TABLE_NAME) || ' ' || where_clause, dbms_sql.native);
 
  -- Describe the table structure:
  -- --------------------------------------------------------
  --  1. Store metadata in tableDesc
  --  2. Store the number of columns in colCount
  -- --------------------------------------------------------
  dbms_sql.describe_columns2(base_stmt, colCount, tableDesc);
 
  -- Define individual columns and assign value to colValue variable.
  FOR i IN 1..colCount LOOP
 
    -- Define columns for each column returned into tableDesc.
    dbms_sql.define_column(base_stmt, i, colValue, 4000);
 
    -- Find the length of the longest column name.
    IF LENGTH(tableDesc(i).col_name) > colLength THEN
      colLength := LENGTH(tableDesc(i).col_name);
    END IF;
 
    -- Replace non-displayable column values with displayable values.
    IF i < colCount THEN
      dynamic_stmt := dynamic_stmt || check_column(tableDesc(i).col_name,tableDesc(i).col_type) || ' AS '
                   || tableDesc(i).col_name || ', ';
    ELSE
      dynamic_stmt := dynamic_stmt || check_column(tableDesc(i).col_name,tableDesc(i).col_type) || ' AS '
                   || tableDesc(i).col_name || ' ' || 'FROM ' || dbms_assert.simple_sql_name(TABLE_NAME)
                   || ' ' || where_clause;
    END IF;
 
  END LOOP;
 
  -- Provide conditional debugging instruction that displays dynamically created query.
  $IF $$DEBUG = 1 $THEN
     dbms_output.put_line(dynamic_stmt);
  $END
 
  -- Prepare unfiltered display cursor. 
  dbms_sql.parse(stmt, dynamic_stmt, dbms_sql.native);
 
  -- Describe the table structure:
  -- --------------------------------------------------------
  --  1. Store metadata in tableDesc (reuse of existing variable)
  --  2. Store the number of columns in colCount
  -- --------------------------------------------------------
  dbms_sql.describe_columns2(stmt, colCount, tableDesc);
 
  -- Define individual columns and assign value to colValue variable.
  FOR i IN 1..colCount LOOP
    dbms_sql.define_column(stmt, i, colValue, 4000);
  END LOOP;
 
  -- Execute the dynamic cursor.
  STATUS := dbms_sql.execute(stmt);
 
  -- Fetch the results, row-by-row.
  WHILE dbms_sql.fetch_rows(stmt) > 0 LOOP
 
    -- Reset row counter for output display purposes.
    rowIndex := rowIndex + 1;
 
    -- Increment the counter for the collection and extend space before assignment.
    rsIndex := rsIndex + 1;
    result_set.EXTEND;
    result_set(rsIndex) := '********************************** ' || rowIndex || '. row **********************************';
 
    -- For each column, print left-aligned column names and values.
    FOR i IN 1..colCount LOOP
 
      -- Increment the counter for the collection and extend space before assignment.
      rsIndex := rsIndex + 1;
      result_set.EXTEND;
 
      -- Limit display of long text.  
      IF tableDesc(i).col_type IN (1,9,96,112) THEN
 
        -- Display 40 character substrings of long text.  
        dbms_sql.column_value(stmt, i, colValue);
        result_set(rsIndex) := RPAD(tableDesc(i).col_name, colLength,' ') || ' : ' || SUBSTR(colValue, 1,40);	  
 
      ELSE
 
        -- Display full value as character string.  
        dbms_sql.column_value(stmt, i, colValue);
        result_set(rsIndex) := RPAD(tableDesc(i).col_name, colLength,' ') || ' : ' || colValue;
 
      END IF;
 
    END LOOP;
 
  END LOOP;
 
  -- Increment the counter for the collection and extend space before assignment.
  FOR i IN 1..3 LOOP
    rsIndex := rsIndex + 1;
    result_set.EXTEND;
 
    CASE i
      WHEN 1 THEN
        result_set(rsIndex) := '****************************************************************************';
      WHEN 2 THEN
        result_set(rsIndex) := CHR(10);    
      WHEN 3 THEN
        result_set(rsIndex) := rowIndex || ' rows in set';    
    END CASE;
  END LOOP;
 
  -- Return collection.
  RETURN result_set;
EXCEPTION
  -- Customer error handlers, add specialized text or collapse into one with the OTHERS catchall.
  WHEN table_name_error THEN
    dbms_output.put_line(SQLERRM);
  WHEN invalid_relational_operator THEN
    dbms_output.put_line(SQLERRM);
  WHEN invalid_identifier THEN
    dbms_output.put_line(SQLERRM);
  WHEN missing_keyword THEN
    dbms_output.put_line(SQLERRM);
  WHEN misquoted_string THEN
    dbms_output.put_line(SQLERRM);
  WHEN OTHERS THEN
    dbms_output.put_line(SQLERRM);
END;
/

Before you attempt to run the function, you should set two Oracle SQL*Plus environment commands. One suppresses a message saying what just ran, and the other removes column headers. Clearly, the output is sufficient and the headers are clutter. You set these, as noted below:

SET FEEDBACK OFF
SET PAGESIZE 0

You can run the function with the following syntax (the COLUMN_VALUE is the standard name returned from a scalar schema-level collection.

SELECT column_value
FROM   TABLE(vertical_query('ITEM','WHERE item_title LIKE ''Star%'''));

It’ll return the following display of data:

********************************** 1. ROW **********************************
ITEM_ID           : 1002
ITEM_BARCODE      : 24543-02392
ITEM_TYPE         : 1011
ITEM_TITLE        : Star Wars I
ITEM_SUBTITLE     : Phantom Menace
ITEM_RATING       : PG
ITEM_RELEASE_DATE : 04-MAY-99
CREATED_BY        : 3
CREATION_DATE     : 09-JUN-10
LAST_UPDATED_BY   : 3
LAST_UPDATE_DATE  : 09-JUN-10
ITEM_DESC         :
DISPLAY_PHOTO     : BLOB NOT displayable.
********************************** 2. ROW **********************************
ITEM_ID           : 1003
ITEM_BARCODE      : 24543-5615
ITEM_TYPE         : 1010
ITEM_TITLE        : Star Wars II
ITEM_SUBTITLE     : Attack OF the Clones
ITEM_RATING       : PG
ITEM_RELEASE_DATE : 16-MAY-02
CREATED_BY        : 3
CREATION_DATE     : 09-JUN-10
LAST_UPDATED_BY   : 3
LAST_UPDATE_DATE  : 09-JUN-10
ITEM_DESC         :
DISPLAY_PHOTO     : BLOB NOT displayable.
********************************** 3. ROW **********************************
ITEM_ID           : 1004
ITEM_BARCODE      : 24543-05539
ITEM_TYPE         : 1011
ITEM_TITLE        : Star Wars II
ITEM_SUBTITLE     : Attack OF the Clones
ITEM_RATING       : PG
ITEM_RELEASE_DATE : 16-MAY-02
CREATED_BY        : 3
CREATION_DATE     : 09-JUN-10
LAST_UPDATED_BY   : 3
LAST_UPDATE_DATE  : 09-JUN-10
ITEM_DESC         : This IS designed TO be a long enough str
DISPLAY_PHOTO     : BLOB NOT displayable.
********************************** 4. ROW **********************************
ITEM_ID           : 1005
ITEM_BARCODE      : 24543-20309
ITEM_TYPE         : 1011
ITEM_TITLE        : Star Wars III
ITEM_SUBTITLE     : Revenge OF the Sith
ITEM_RATING       : PG13
ITEM_RELEASE_DATE : 19-MAY-05
CREATED_BY        : 3
CREATION_DATE     : 09-JUN-10
LAST_UPDATED_BY   : 3
LAST_UPDATE_DATE  : 09-JUN-10
ITEM_DESC         :
DISPLAY_PHOTO     : BLOB NOT displayable.
****************************************************************************

As usual, I hope this helps folks.

Written by maclochlainn

June 14th, 2010 at 1:01 am

Posted in MySQL,Oracle,Oracle XE,pl/sql,sql

Tagged with ,

Goodbye to my iPhone

with 4 comments

For almost two years, I’ve loved my iPhone. That’s amazing, since I live where AT&T has never provided 3G coverage. The contract expires this summer.

Admittedly, business trips were refreshing because I generally always had a 3G connection. That is, until the last six months or so. During that period of time, I’ve been experiencing some random dropped calls. For example, AT&T dropped my 3G connections about 8 times in less than 30 minutes in April. All three calls went over 5 minutes before they were dropped, and they were made from a hotel in Anaheim, California (near Angels Stadium). Those drops certainly made it appear that their system couldn’t handle the volume of concurrent calls, but it could have been something else. 😉

The final straw was AT&T’s unlimited data plan change announcement. Wow! It caught me by surprise. Their back peddling with a subsequent announcement of qualified renewed contracts doesn’t work for me. They’ve lost what little trust I had for them.

Fortunately, I’d deferred buying an iPad. I’d planned to order an iPad 3G model this last week, but now it will definitely be a Wi-Fi only device! I’m also deferring the purchase now to see if there’s another surprise in the wings.

When I compare the cost of my iPhone against the HTC EVO, the iPhone loses. I found Daniel Lyon’s article Phone Fight! interesting for many reasons. While his comparison of Microsoft versus Apple of yesteryear to Google versus Apple of today is interesting, this quote strikes me:

“Right now the most advanced smart phone on the market is arguably not the new iPhone 4 but rather an Android device called the EVO 4G, made by HTC, a Taiwanese company. That phone has front and rear cameras, and shoots hi-def video, just like the new iPhone 4. But the EVO has a bigger display, its camera shoots in higher resolution, and it can turn itself into a mobile Wi-Fi hotspot, something the iPhone 4 can’t do.”

The mobile Wi-Fi hotspot means my iPad Wi-Fi works virtually anywhere. That alone is probably the single most important reason why I considered dropping my iPhone. Alas, I was disabused of the notion today by David Pogue (6/17/2010). The battery life is pathetic.

Let’s face it: the iPhone interface is AWESOME! Therefore, my idea of replacing my iPhone with an EVO will be a nearly forgotten memory, like my HP-25C of college days and Star Wars IV premiere gone by …

Written by maclochlainn

June 13th, 2010 at 12:55 am

Posted in EVO,iPhone

A couple DBMS_SQL limits

without comments

While developing a dynamic SQL example in Oracle 11g that builds a query based on available display columns, I found two interesting error messages. Now instead of noting it for the umpteenth time, I’m documenting it for everybody. The error messages are generated when this DBMS_SQL package’s statement is a SELECT statement, and is executed with either a BLOB, BFILE or CFILE column in the list of returned columns.

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STATUS := dbms_sql.execute(stmt);

BLOB data type

You get the following error when a column in the query has a BLOB data type. If you alter the query to exclude the column, no error occurs.

BEGIN test('DEMO'); END;
*
ERROR at line 1:
ORA-00932: inconsistent datatypes: expected NUMBER got BLOB
ORA-06512: at "SYS.DBMS_SQL", line 1575
ORA-06512: at "STUDENT.TEST", line 26
ORA-06512: at line 1

BFILE or CFILE data type

You get the following error when a column in the query has a BFILE or CFILE data type. If you alter the query to exclude the column, no error occurs.

BEGIN test('DEMO'); END;
*
ERROR at line 1:
ORA-00932: inconsistent datatypes: expected NUMBER got FILE
ORA-06512: at "SYS.DBMS_SQL", line 1575
ORA-06512: at "STUDENT.TEST", line 26
ORA-06512: at line 1

It’s never a joy to debug the DBMS_SQL package, at least it’s never a joy for me. I hope this helps somebody sort out an issue more quickly.

Written by maclochlainn

June 12th, 2010 at 11:43 pm

Posted in blob,clob,Oracle,Oracle XE,pl/sql,sql

VMWare Fusion Permissions

with 3 comments

It’s always interesting when I have to sort out problems with VMWare Fusion on my Mac OS X. Right, as you guessed, interesting means frustrating. 😉 What started the whole thing was my investigating why VMWare networking would sometimes not start. I noticed the problem began after my upgrade to VMWare Fusion 3.1.0 (261058).

Rather than reboot the Mac OS X, which has fixed the problem, I tried to restart the service after closing my VMs. You can find how to do that in this older post of mine.

When I tried to restart it with the following command:

# sudo /Library/Application\ Support/VMware\ Fusion/boot.sh  --restart

I got the following error on VMWare file permissions:

VMware Fusion 261058: Shutting down VMware Fusion: 
Stopped DHCP service on vmnet1
Disabled hostonly virtual adapter on vmnet1
Stopped DHCP service on vmnet8
Stopped NAT service on vmnet8
Disabled hostonly virtual adapter on vmnet8
Stopped all configured services on all networks
No matching processes were found
No matching processes were found
No matching processes were found
No matching processes were found
No matching processes were found
No matching processes were found
(kernel) Kext com.vmware.kext.vmcrosstalk not found for unload request.
Failed to unload com.vmware.kext.vmcrosstalk - (libkern/kext) not found.
(kernel) Kext com.vmware.kext.vmmon not found for unload request.
Failed to unload com.vmware.kext.vmmon - (libkern/kext) not found.
 
VMware Fusion 261058: Starting VMware Fusion: 
2010-06-10 22:22:30.588 repair_packages[455:607] PackageKit: *** Missing bundle identifier: /Library/Receipts/vpn.pkg
Verifying files from package 'com.vmware.fusion.application' on '/'.
	Permissions differ on "Library/Application Support/VMware Fusion/VMDKMounter.app/Contents/MacOS/vmware-vmdkMounter", should be -rwxr-xr-x , they are -rwsr-xr-x .
	Warning: SUID file 'Library/Application Support/VMware Fusion/VMDKMounter.app/Contents/MacOS/vmware-vmdkMounter' has been modified and will not be repaired.
Finished verifying files from package 'com.vmware.fusion.application' on '/'.
Started network services
Verifying and re-installing files from /Library/Application Support/VMware Fusion/thnuclnt

Navigating to the directory, an ls -al found the two files below and their respective permissions.

drwxr-xr-x  4 root  wheel      136 Jun 10 22:51 .
drwxr-xr-x  5 root  wheel      170 May 27 21:22 ..
-rwsr-xr-x  1 root  wheel  1593620 May 21 03:51 vmware-vmdkMounter
-rwsr-xr-x  1 root  wheel  1475396 May 21 03:51 vmware-vmdkMounterTool

I thought perhaps both files required the same permissions but I was wrong. If you change the permissions on the vmware-vmdkMounterTool file, you’ll raise an error telling you that it should be -rwsr-xr-x. If you make that same mistake too, I’ve got the reset syntax at the bottom of the post.

You should only change the file permissions of vmware-vmdkMounter file. The following syntax lets you remove the sticky bit from the user permissions but you’ll need the root password (the administrator password).

sudo chmod u=rwx,go=rx vmware-vmdkMounter

That should leave you with the following permissions:

drwxr-xr-x  4 root  wheel      136 Jun 10 22:51 .
drwxr-xr-x  5 root  wheel      170 May 27 21:22 ..
-rwxr-xr-x  1 root  wheel  1593620 May 21 03:51 vmware-vmdkMounter
-rwsr-xr-x  1 root  wheel  1475396 May 21 03:51 vmware-vmdkMounterTool

When you restart you should get the following pseudo clean output. Pseudo because apparently the two errors are not meaningful. At least, I couldn’t find anything on them and VMWare Fusion now works. I’ll probably investigate this a bit more later, and I’ll update anything in this post. If you know something, post it as a comment to help everybody.

VMware Fusion 261058: Shutting down VMware Fusion: 
Stopped DHCP service on vmnet1
Disabled hostonly virtual adapter on vmnet1
Stopped DHCP service on vmnet8
Stopped NAT service on vmnet8
Disabled hostonly virtual adapter on vmnet8
Stopped all configured services on all networks
No matching processes were found
No matching processes were found
No matching processes were found
No matching processes were found
No matching processes were found
No matching processes were found
(kernel) Kext com.vmware.kext.vmcrosstalk not found for unload request.
Failed to unload com.vmware.kext.vmcrosstalk - (libkern/kext) not found.
(kernel) Kext com.vmware.kext.vmmon not found for unload request.
Failed to unload com.vmware.kext.vmmon - (libkern/kext) not found.
 
VMware Fusion 261058: Starting VMware Fusion: 
2010-06-10 22:58:45.276 repair_packages[861:607] PackageKit: *** Missing bundle identifier: /Library/Receipts/vpn.pkg
Verifying files from package 'com.vmware.fusion.application' on '/'.
Finished verifying files from package 'com.vmware.fusion.application' on '/'.
Started network services
Verifying and re-installing files from /Library/Application Support/VMware Fusion/thnuclnt

If you fat fingered the resetting command and also changed the vmware-vmdkMounterTool file permissions, you can reset them to shared user by using the following syntax:

sudo chmod u=rwxs,go=rx vmware-vmdkMounterTool

As always, I hope this helps others.

Written by maclochlainn

June 10th, 2010 at 11:28 pm

Posted in bash,Linux,Mac,Mac OS X,VMWare

LIKE operator in Excel

with 2 comments

While discussing the limitations of wild card comparisons in the Microsoft Excel’s IF function, I resolved to share my ISLIKE function. It acts like the LIKE operator in SQL. You can’t use the word like as the function name because it’s a reserved word in Visual Basic for Applications (VBA).

The function lets you compare any string to see if it is contained in another string. The default mode is case-insensitive, and the override mode case-sensitive. The optional third element lets you override the default comparison method.

You should remember or note that a number 0 is always evaluated as false, and any other number (negative or positive) is always true. You can put the ISLIKE function in a macro sheet or an Add-in library. I recently posted instructions on how to create your own Add-in library.

Here is the VBA code for the user defined ISLIKE function:

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Function ISLIKE( inValue As Variant _
               , hasValue As Variant _
               , Optional caseSensitive As Integer = 0)
 
  ' Define a logical return variable and assign a default value.
  Dim logicReturn As Boolean
  logicReturn = False
 
  If caseSensitive Then
 
    ' Finds a case-insensitive value as a component in a larger value.
    If inValue Like "*" + hasValue + "*" Then
      logicReturn = True
    End If
 
  Else
 
    ' Finds a case-sensitive value as a component in a larger value.
    If UCase(inValue) Like "*" + UCase(hasValue) + "*" Then
      logicReturn = True
    End If
 
  End If
  ' Return the logical value.
  ISLIKE = logicReturn
 
End Function

Line numbers 12 and 19 use the "*", which is equivalent to the regular expression of "\.*". I’ve no idea why they made this choice, and it’s not well explained on Microsoft’s web site covering SmartTags.

You can shorten the program and make it slightly less efficient by performing the case sensitive match twice. The following doesn’t rely on nested block IF statements. You also must change the third parameter to a Boolean or the Not operator won’t work correctly.

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Function ISLIKE( lookupValue As Variant _
               , containsValue As Variant _
               , Optional caseSensitive As Boolean = 0)
 
  ' Define a logical return variable and assign a default value.
  Dim logicReturn As Boolean
  logicReturn = False
 
  ' Finds a case-insensitive value as a component in a larger value.
  If caseSensitive And _
     lookupValue Like "*" + containsValue + "*" Then
      logicReturn = True
 
  ' Finds a case-sensitive value as a component in a larger value.
  ElseIf Not caseSensitive And _
    UCase(lookupValue) Like "*" + UCase(containsValue) + "*" Then
      logicReturn = True
 
  End If
 
  ' Return the logical value.
  ISLIKE = logicReturn
 
End Function

Somebody asked me, “How this can be useful?” That meant from their perspective, how is it useful beyond a comparison of cell values. A quick example of that additional utility can be demonstrated from an early post. In that post on replacing a VLOOKUP function with a UDF, there’s compound logic used to find the occurrence of a substring in a string. The ISLIKE function can simplify that logic.

Here’s that snippet of the code from that referenced post. The snippet evaluates whether the base string is greater than one character and checks the second character of the string to see if it is a - (minus sign).

58

ElseIf Len(LetterGrades(i)) > 1 And Mid(LetterGrades(i), 2, 1) = "-" Then

You can replace the compound logic with a call to the LIKE function. It would replace line 58 as follows:

58

ElseIf ISLIKE(LetterGrades(i),"-") Then

The logic of the function examines to see if the first parameter contains the second parameter. This is what is meant by like. In the following illustration, you examine if a string contains a substring (or is like a substring). The cell A2 is also assigned a Range name. Range names can increase the readability of your models and functions. All but the last one perform case insensitive comparisons that find whether the substring in cell A2 is found with cell range of the B5:B10. The B10 formula performs a case sensitive match.

Another logic comparison uses grades to see if a minus sign is found in them. The example compares the cell values in A1 and A2 against the B1 and B2 values. Returning true for one and false for the other cases in column C of the respective rows.

Here are the calls to the ISLIKE user defined function. The first one is case-insensitive and the second case-sensitive, but there’s no case sensitivity with a minus sign, -.

Spreadsheet Functions
Cell Formula
C1 =ISLIKE(A1,B1)
C2 =ISLIKE(A2,B2,TRUE)

As always, I hope this helps. If you’ve comments or alternative approaches, please let me know.

Written by maclochlainn

June 4th, 2010 at 11:28 am

Posted in Microsoft Excel,Microsoft Office,VBA,VBA Tutorial

Tagged with , , ,

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