MacLochlainns Weblog

Michael McLaughlin's Technical Blog

Site Admin

Archive for the ‘MySQL’ Category

Common Lookup Tables 2

with 2 comments

Last October I posted an example and description of a common_lookup table. It was intended to show how common_lookup tables support drop down selections in web forms. However, it wasn’t adequate to show how they work with existing data, and the function only supported fresh queries.

This post goes to the next level, and shows how to use foreign keys to preselect values for display in web forms. It also rewrites the prior function so that it supports querying existing data and inserting new data.

Let’s start with data stored in join between two tables – the member and contact tables. The internal lookup uses the customers name from the contact table to find the membership account information in the member table.

1
2
3
4
5
6
7
8
9
10
11
12
13
SELECT   m.account_number
,        m.member_type         -- A fk to common_lookup table.
,        m.credit_card_number
,        m.credit_card_type    -- A fk to common_lookup table.
,        c.first_name
,        c.middle_name
,        c.last_name
,        c.contact_type        -- A fk to common_lookup table.
FROM     member m INNER JOIN contact c
ON       m.member_id = c.member_id
WHERE    c.first_name = 'Harry'
AND      c.middle_name = 'James'
AND      c.last_name = 'Potter'\G

It returns the results on the left, while a set of joins against the common_lookup table returns the results on the right (both use the \G in SQL Monitor to display the data vertically).

CommonLookupQueryResults01CommonLookupQueryResults01b

The member_type, credit_card_type, and contact_type columns in the data set on the left hold foreign key values. They’re copies of values found in the primary key column of the common_lookup table. You have the option of using these values to connect the data through a join or through function calls. A join requires three copies of the common_lookup table and yields the data displayed on the right above. The query to get the meaningful business information from the common_lookup table is:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
SELECT   m.account_number
,        cl1.common_lookup_meaning
,        m.credit_card_number
,        cl2.common_lookup_meaning
,        c.first_name
,        c.middle_name
,        c.last_name
,        cl3.common_lookup_meaning
FROM     member m INNER JOIN contact c
ON       m.member_id = c.member_id INNER JOIN common_lookup cl1
ON       cl1.common_lookup_id = m.member_type INNER JOIN common_lookup cl2
ON       cl2.common_lookup_id = m.credit_card_type INNER JOIN common_lookup cl3
ON       cl3.common_lookup_id = c.contact_type
WHERE    c.first_name = 'Harry'
AND      c.middle_name = 'James'
AND      c.last_name = 'Potter'\G

The data returned from any query is symmetrical, which means all columns return the same number of rows. The results of the preceding query are the business results. Although, they’re not what you’d want to display in a web form that presents the ability to change values, like the member, credit card, or contact types. You need to get that information by using the foreign key as a parameter to a function call, and in this case three function calls. One for each of the foreign keys from the original query results. The result is an asymmetric collection of data would look like the following conceptually with Lily Luna Potter as the customer (note the green row is the symmetrical return set from the preceding query):

AsymmetricalQueryData

The f(x) represents a generic function call where the x substitutes for the foreign key value as a lookup key to the primary key value of the common_lookup table. The function in this case is a query that returns a two column list. One column holds the primary key value of the (common_lookup_id) and the other holds the customer facing description (from the common_lookup_meaning column).

These steps describe the process:

  1. Use the natural key (the user name) to find the data in the contact table.
  2. Use the member_id foreign key column in the contact table to link to the same name column primary key in the member table by joining the two rows.
  3. Use the foreign keys in the new row (combining columns from the contact and member tables) as call parameters to a PHP function that returns all possible foreign key values and their business descriptions in a web form.

The vertical choices displayed above map to OPTION tag elements of an HTML SELECT tag. The blue highlighted value contains an instruction, Select Type, in the display of an HTML OPTION tag, and it holds a null as the value of the VALUE attribute for the OPTION tag. The other displayed rows are the possible values. The green highlighted value is the currently selected value and the yellow highlighted values are alternate possibilities for an end-user to select. The logic for that process is in the PHP get_common_lookup function below.

Having discussed the structure of the data and problem, we’ll present the result in a dynamically constructed web form below. The display form shows a member account with customer information.

CommonLookupQueryResults02

You should note that the primary and foreign keys aren’t displayed because they’re irrelevant to the business process. Primary and foreign keys only serve to support relationships when we use surrogate keys as the primary key of a table. Only the meaningful information from the common_lookup table are displayed in the preceding form. Behind the web form, the primary and foreign key values are critical to maintaining anomaly free table data.

Each of the drop downs contains the full selection of possibilities from the common_lookup table, and an end-user could choose a new value by clicking on any of the drop down fields. For example, the following displays the selection of a type of credit card:

CommonLookupQueryResults03

The user can click on the drop down, and then navigate from the selection to a new selection. Assuming we don’t change anything, submitting the form should transmit the foreign key column values. The following shows that’s exactly what it does:

CommonLookupQueryResults04

As you can see from the screen shot it works easily. Below is the PHP code for a MySQL credentials file and the get_lookup function. The function lets you find an existing value or returns a set of unique values for you to choose from.

You should rename the following credentials.php file as MySQLCredentials.inc for it to work in the file below it.

Assuming you’ve implemented the credentials.php file as the MySQLCredentials.inc file, you can now implement the following file. The get_common_lookup function returns a <SELECT> tag with a list embedded of <OPTION> tags with values; one <OPTION> tag is selected when the foreign key matches a valid primary key value in the common_lookup table; and no <OPTION> tag is selected when the foreign key doesn’t match a a valid primary key value in the common_lookup table. The last possibility means a user must choose a new valid value for the foreign key column when the foreign key column is constrained as a mandatory or not null column.

The code for the web form is a bit more complex, as shown below. It contains three separate calls to the modified get_common_lookup function (on lines 104, 111, and 126). Each call to the get_common_lookup function selects the list of possible values and highlights the value associated with the foreign key value.

Here’s the web form code. You should note that it only returns a single row of data from the query by using a natural key from the contact table.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
<html>
<header>
<title>Select Option Sample</title>
<style type="text/css">
  /* Class tag element styles. */
  .box {border:1px solid;padding:0px;width:392px;background-color:silver;}
  .bottomBox {border-left:1px solid;border-right:1px solid;border-bottom:1px solid;padding:5px;width:380px;background-color:silver;}
  .middleBox {border:1px solid;padding:5px;width:380px;background-color:silver;}
  .topBox {border-left:1px solid;border-right:1px solid;border-top:1px solid;padding:5px;width:380px;background-color:silver;}
  .button {margin:5px;background-color:lightblue;font-weight:bold;align:right;}
  .clear {clear:left;}
  .dropDown {min-width:50px;display:block;float:left;text-align:left;color:black;}
  .formDownLabel {width:90px;display:block;float:left;margin:5px;text-align:right;vertical-align:bottom;color:black;}
  .formAcrossLabel {width:80px;display:block;float:left;padding-bottom:0px;margin:5px 5px 0px;text-align:left;vertical-align:bottom;font-style:italic;font-size:90%;color:black;}
  .formInput {min-width:150px;margin:5px;text-align:left;}
  .formShortInput {width:80px;margin:5px;text-align:left;}
  .title1 {margin-left:0px;font-weight:bold;font-style:italic;font-size:125%;color:black;}
  .title2 {margin-left:5px;font-weight:bold;font-style:italic;font-size:105%;color:black;}
</style>
</header>
<body>
<?php
 
  // Include libraries.
  include_once("MySQLCredentials.inc");
  include_once("library.inc");
 
  // Define a HTML page string.
  $out = '';
 
  // Declare input variables.
  $first_name = (isset($_GET['first_name'])) ? $_GET['first_name'] : $first_name = "Harry";
  $middle_name = (isset($_GET['middle_name'])) ? $_GET['middle_name'] : $middle_name = "James";
  $last_name = (isset($_GET['last_name'])) ? $_GET['last_name'] : $last_name = "Potter";
 
  // Declare output variables.
  $member_account_number = null;
  $credit_card_number = null;
 
  // Declare lookup input and output (initialized as nulls to suppress warnings) variables.  
  $member_table = 'member';
  $member_type = 'member_type';
  $member_type_id = null;
  $credit_card_type = 'credit_card_type';
  $credit_card_type_id = null;
  $contact_table = 'contact';
  $contact_type = 'contact_type';
  $contact_type_id = null;
 
  // Assign credentials to connection.
  $mysqli = new mysqli(HOSTNAME, USERNAME, PASSWORD, DATABASE);
 
  // Check for connection error and print message.
  if ($mysqli->connect_errno) {
    print $mysqli->connect_error."<br />";
    print "Connection not established ...<br />";
  }
  else {
    // Initial statement.
    $stmt = $mysqli->stmt_init();
 
    // Declare a static query.
    $sql = "SELECT   m.account_number\n"
         . ",        m.member_type\n"
         . ",        m.credit_card_number\n"
         . ",        m.credit_card_type\n"
         . ",        c.first_name\n"
         . ",        c.middle_name\n"
         . ",        c.last_name\n"
         . ",        c.contact_type\n"
         . "FROM     member m INNER JOIN contact c\n"
         . "ON       m.member_id = c.member_id\n"
         . "WHERE    c.first_name = ?\n"
         . "AND      c.middle_name = ?\n"
         . "AND      c.last_name = ?\n";
 
    // Prepare statement.
    if ($stmt->prepare($sql)) {
      $stmt->bind_param("sss",$first_name,$middle_name,$last_name); } 
 
    // Attempt query and exit with failure before processing.
    if (!$stmt->execute()) {
 
      // Print failure to resolve query message.
      print $mysqli->error."<br />";
      print "Failed to resolve query ...<br />";
    }
    else {   
      // This query only returns one row, and an empty block follows the while logic.
      $stmt->bind_result($member_account_number, $member_type_id, $credit_card_number, $credit_card_type_id, $first_name, $middle_name, $last_name, $contact_type_id);
      while ($stmt->fetch()) {}
    }
  }
 
  // Print the query form.
  $out .= '<form method="post" name="myForm" action="submitItemType.php">';
  $out .= '<label class="title1">Membership Account Information</label><br />';
  $out .= '<div class="box">';
  $out .= '<div class="topBox">';
  $out .= '<label class="formDownLabel">Account #</label><input class="formInput" type="text" value="'.$member_account_number.'" />';
  $out .= '<select name="member_type" size="1" onChange="change(this.form.member_type)">';
 
  // Get dynamic membership type lookup string fragment.
  $out .= get_common_lookup($member_table, $member_type, $member_type_id);
 
  $out .= '</select><br />';
  $out .= '<label class="formDownLabel">Credit Card #</label><input class="formInput" type="text" value="'.$credit_card_number.'" />';
  $out .= '<select name="credit_card_type" size="1" onChange="change(this.form.credit_card_type)">';
 
  // Get dynamic credit card type lookup string fragment.
  $out .= get_common_lookup($member_table, $credit_card_type, $credit_card_type_id);
 
  // Print the closing HTML table tag.
  $out .= '</select><br />';
  $out .= '</div>';
  $out .= '<div class="middleBox">';
  $out .= '<label class="formDownLabel">&nbsp;</label>';
  $out .= '<label class="formAcrossLabel">First Name</label><label class="formAcrossLabel">Middle Name</label><label class="formAcrossLabel">Last Name</label><br class="clear" />';
  $out .= '<label class="formDownLabel">Customer</label><input class="formShortInput" type="text" value="'.$first_name.'" />';
  $out .= '<input class="formShortInput" type="text" value="'.$middle_name.'" />';
  $out .= '<input class="formShortInput" type="text" value="'.$last_name.'" /><br />';
  $out .= '<label class="formDownLabel">Type</label>';
  $out .= '<select style="margin:5px" name="contact_type" size="1" onChange="change(this.form.contact_type)">';
 
  // Get dynamic membership type lookup string fragment.
  $out .= get_common_lookup($contact_table, $contact_type, $contact_type_id);
 
  $out .= '</select><br />';
  $out .= '</div>';
  $out .= '<div class="bottomBox">';
  $out .= '<input class="button" style="margin-left:300px" name="submit" type="submit" value="Submit">';
  $out .= '</div>';
  $out .= '</form>';
  $out .= '</body>';
  $out .= '</html>';
 
  print $out;
?>
</body>
</html>

The submit button simply runs another web page that prints the actual values for the drop down selections. Here’s the code to print that:

1
2
3
4
5
6
7
8
9
10
11
12
<html>
<head>
</head>
<body>
<?php
  // Print the surrogate key values for the common_lookup_id column.
  print "MEMBER_TYPE -> [".$_POST['member_type']."]<br />";
  print "CREDIT_CARD_TYPE -> [".$_POST['credit_card_type']."]<br />";
  print "CONTACT_TYPE -> [".$_POST['contact_type']."]<br />";
?>
</body>
</html>

I hope this helps those who are interested in sorting how to implement a common_lookup table.

Written by maclochlainn

February 1st, 2013 at 1:47 am

MySQL Auto Increment

with one comment

Somebody ran into a problem after reading about the MySQL CREATE statement and the AUTO_INCREMENT option. They couldn’t get a CREATE statement to work with an AUTO_INCREMENT value other than the default of 1. The problem was they were using this incorrect syntax:

CREATE TABLE elvira
( elvira_id    int unsigned PRIMARY KEY AUTO_INCREMENT=1001
, movie_title  varchar(60))
  ENGINE=InnoDB
  CHARSET=utf8;

It raises this error:

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '=1001
, movie_title  varchar(60))
  ENGINE=InnoDB
  CHARSET=utf8' at line 2

They concluded that MySQL requires you to assign a default value of 1 as the initial automatic numbering value; then you use the ALTER statement to change the initial sequence value. That assumption is incorrect. The problem was with their assignment of an overriding AUTO_INCREMENT value inside the parenthetical list of columns. That assignment needs to occur after the list of columns and constraints, like

CREATE TABLE elvira
( elvira_id    int unsigned PRIMARY KEY AUTO_INCREMENT
, movie_title  varchar(60))
  ENGINE=InnoDB
  AUTO_INCREMENT=1001
  CHARSET=utf8;

It’s not an unlikely mistake since there’s no clear example on either of the referenced web pages (at the time of writing). It would be nice if they were added but I’m of the opinion some of the reference manual pages are too sparse.

After creating the table, you have the generic fix that seems to appear most often as an answer to setting or re-setting the auto numbering sequence of a MySQL table:

ALTER TABLE elvira AUTO_INCREMENT=1001;

Why would you set the auto numbering sequence to something other than 1? Some designers consider it a best practice to increment from a set point like 101 or 1,001 for your Application Programming Interface (API) and they leave a readily identifiable sequence number set for pre- or post-seeded data in tables. The region of preallocated numbers are typically only used in a few of the tables, in any application, but consistently managing sequences across all tables does sometimes simplifies data diagnostics.

Hope this helps somebody looking for a syntax fix. By the way, you can find it on Page 162 of the Oracle Database 11g & MySQL 5.6 Developer Handbook.

Written by maclochlainn

January 29th, 2013 at 1:10 am

Posted in MySQL,MySQL Workbench,sql

Tagged with ,

Mountain Lion Pre-MySQL

with 10 comments

While I try to contain everything about installing MySQL in a single post that I update from time-to-time, Mac OS X, Mountain Lion (10.8.x), requires some pre-steps. You must install XCode, and the Command Line Tools. This post provides the screen shots and step-by-step instructions.

Before you can do any of these steps, you must connect to the Apple Store and download XCode. Dependent on your internet speed this may take some time. Generally, it’s an hour or less.

  1. After installing XCode, click the Rocket Spaceship in the Mac Dock to launch a view of your Applications. Launch XCode by clicking on the hammer overlaying the blue background XCode icon shown below.

  1. After launching XCode, click the Install button on the lower right of the System Component Installation screen shown below.

  1. You’re prompted for your default user (actually a sudoer authorized user) password. Enter it in the dialog and click the OK button to continue.

  1. After entering the valid credentials and a couple minutes, you should see the System Component Installation screen shown below. Click the Start Using XCode button to continue.

  1. Inside XCode, click on the XCode menu option and select the Preferences menu option, as shown below.

  1. You should be on the General tab of XCode’s Preferences dialog. Click on the Downloads tab.

  1. You should see three choices (at the time of writing) in the Downloads tab. As shown, select the Command Line Tools item. It should take only a couple minutes to download. Click the Install button to continue.

  1. The Install button disappears and is replaced by an Installed label when the Command Line Tools are installed. You should see the following screen shot.

After completing these steps, return to the other post to install and configure MySQL. While it seems this exists already as content on Apple’s site, it seems some folks wanted me to add it with the step-by-step screen shots.

Written by maclochlainn

December 10th, 2012 at 8:55 pm

Posted in Mac,Mac OS X,MAMP,MySQL,Xcode

Tagged with , ,

MySQL Database Triggers

with 3 comments

One of the students wanted an equivalent example to an Oracle DML trigger sample that replaces a white space in a last name with a dash for an INSERT statement. Apparently, the MySQL trigger example in the Oracle Database 11g and MySQL 5.6 Developer Handbook was a bit long. I have to agree with that because the MySQL DML trigger demonstrated cursors and loops in the trigger code.

Triggers can be statement- or row-level actions. Although some databases let you define statement-level triggers, MySQL doesn’t support them. MySQL only supports row-level triggers. Row-level triggers support critical or non-critical behaviors. Critical behavior means the trigger observes an insert, update, or delete that must be stopped, which means it raises an error. Non-critical behavior means the trigger observes a DML statement and logs it or implements a change during the context of the DML activity.

The first example shows you non-critical behavior. It observes an attempt to enter a two-part last name, and replaces the white space with a dash (you can find help on MySQL Regular Expressions in this other post). This means the trigger ensures compliance on how names are entered in the database, which should be protected in the web form (through JQuery or JavaScript) and the database.

DELIMITER $$
DROP TRIGGER IF EXISTS contact_insert$$
 
CREATE TRIGGER contact_insert
BEFORE INSERT ON contact
FOR EACH ROW
BEGIN
  IF new.last_name REGEXP '^.* .*$' THEN
    SET new.last_name := REPLACE(new.last_name,' ','-');
  END IF;
END;
$$
 
DELIMITER ;

The problem with implementing a non-critical trigger is that the database performs the work but clerks entering the data don’t learn the business rule. A critical trigger simply disallows non-conforming data entry. The next program shows a critical behavior with an UPDATE statement row-level trigger. After all, won’t a data entry clerk update the entry with a white space after the INSERT statement didn’t?

Yes, that was a rhetorical question. Spelling out the business rule in the UPDATE statement row-level trigger should educate the persistent errant behavior. While letting the INSERT statement row-level trigger manage the behavior probably saves time for most end-users who make a casual mistake.

DELIMITER $$
DROP TRIGGER IF EXISTS contact_update$$
 
CREATE TRIGGER contact_update
BEFORE UPDATE ON contact
FOR EACH ROW
BEGIN
  IF new.last_name REGEXP '^.* .*$' THEN
    SIGNAL SQLSTATE '42000';
  END IF;
END;
$$
 
DELIMITER ;

Somebody wanted to know why I choose SQLSTATE 42000. That’s because it signals an error in the SQL statement, and that’s the closest existing SQLSTATE to the actual behavior that exists. Moreover, the error identified by the critical trigger signals non-compliance with the application’s SQL standards that protects the data.

Hopefully, this helps somebody looking for a MySQL database trigger example that raises an exception. The example works with MySQL 5.5 forward because the critical trigger uses the SIGNAL feature, which was introduced in MySQL 5.5. Another article shows you how to leverage MyISAM tables to create a logging mechanism for critical event triggers, and you click this link to the MySQL Triggers with Logging blog entry.

Written by maclochlainn

November 22nd, 2012 at 11:32 pm

Common Lookup Tables 1

with one comment

My students wanted an example of how to use a lookup table in the database. I thought it would be a great idea to create a simple example like this one. You can read further on my second post about common lookup tables.

A lookup table is a generalization that holds lists of values that support end-user selections. The following example uses a combination of the common_lookup_table and common_lookup_column columns to identify sets of value for drop down lists. The end-user selects a value from the list to identify a unique row, and returns a common_lookup_id surrogate key value.

The sample code uses the table defined in the previous illustration. It uses a simple HTML drop down list, a PHP library.inc file, and an HTML display form. Below is the drop down selection set for a table and column value.

The drop down list code uses an insecure and trivial GET method to keep the example simple, as shown below:

<html>
<header>
<title>Select Option Sample</title>
<style type="text/css">
  /* Class tag element styles. */
  .label {min-width:200px;text-align:left;}
  .title {font-weight:bold;font-style:italic;font-size:125%;}
</style>
</header>
<body>
<?php
 
  // Include libraries.
  include_once("library.inc");
 
  // Declare input variables.
  $table_name = (isset($_GET['table_name'])) ? $_GET['table_name'] : $table_name = "item";
  $column_name = (isset($_GET['column_name'])) ? $_GET['column_name'] : $column_name = "item_type";
 
  // Call function.
  get_lookup($table_name, $column_name);
 
?>
</body>
</html>

The library.inc file contains the logic to use a PHP prepared statement to read and render a SELECT HTML tag. It uses OPTION tags for all values in the drop down list. The values for the OPTION tag are the surrogate key values from the common_lookup_id column of the common_lookup table, and text elements are the descriptive values from the common_lookup_meaning column.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
<?php
/*
||  Program Name: library.inc
*/
function get_lookup($table_name, $column_name) {
 
  // Assign credentials to connection.
  $mysqli = new mysqli("localhost", "student", "student", "studentdb");
 
  // Check for connection error and print message.
  if ($mysqli->connect_errno) {
    print $mysqli->connect_error."<br />";
    print "Connection not established ...<br />";
  }
  else {
    // Initial statement.
    $stmt = $mysqli->stmt_init();
 
    // Declare a static query.
    $sql = "SELECT   cl.common_lookup_id\n"
         . ",        cl.common_lookup_meaning\n"
         . "FROM     common_lookup cl\n"
         . "WHERE    common_lookup_table = ?\n"
         . "AND      common_lookup_column = ?\n"
         . "ORDER BY 2";
 
    // Prepare statement.
    if ($stmt->prepare($sql)) {
      $stmt->bind_param("ss",$table_name,$column_name); }
 
    // Loop through a result set until completed.  
    do {
 
      // Attempt query and exit with failure before processing.
      if (!$stmt->execute()) {
 
        // Print failure to resolve query message.
        print $mysqli->error."<br />";
        print "Failed to resolve query ...<br />";
      }     
      else {
 
        // Fetch a row for processing.
        $result = $stmt->get_result();
 
        // Print the opening select tag.
        print '<form method="post" name="myForm" action="submitItemType.php">';
        print '<div class="title">Select unique from list:</div>';
        print '<select name="item_type" size="1" onChange="change(this.form.item_type)">';
        print "<option class=label value='' selected>Select &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</option>";
 
        // Read through the rows of the array.        
        while( $row = $result->fetch_array(MYSQLI_NUM) ) {
          print "<option class=label value='".$row[0]."'>".$row[1]."</option>";
        }
      }
    } while($stmt->next_result());
 
  // Print the closing HTML table tag.
  print '</select>';
  print '<input name="submit" type="submit" value="Submit">';
  print '</form>';
 
  // Release connection resource.
  $mysqli->close(); }
  }
?>

The display form action calls the submitItemType.php program, which displays the value from the OPTION tag selected in the prior form. The code for the display is:

<html>
<head>
</head>
<body>
<?php print "ITEM_TYPE -> [".$_POST['item_type']."]"; ?>
</body>
</html>

It generates:

Hope this helps illustrate the value of and mechanics of lookup tables. As mentioned above, there’s a newer post on how to leverage common_lookup tables with more working code.

Written by maclochlainn

October 22nd, 2012 at 1:35 am

Posted in HTML,MySQL,PHP

Tagged with ,

Open World 2012

with 2 comments

In prior years a daily update from Open World was possible, but this year my schedule was too full to support it. This is my compendium of thoughts about MySQL Connect, JavaOne, and Open World 2012.

MySQL Connect was great – good sessions re-enforcing the positive investments Oracle is making in the product. I’ll leave to others to qualify changes in what elements of technology are opened or closed along the road to a better MySQL. The announcement of Connector/Python 1.0 GA on Saturday was great news and as a community we owe a lot to Greet Vanderkelen.

NoSQL is a hot topic along with using JSON objects and it was interesting hearing of some unequal testing paradigms to position non-Oracle solutions to be “better” than Oracle solutions. Naturally, the MongoDB was the elephant in the room during those conversations. Some of the discussions seemed more like political rants than technical dialog. A great spot to start with NoSQL and JSON would be downloading Oracle’s MySQL 5.6 Release Candidate.

There were also more PostgreSQL conversations this year and fairly accurate comparisons between it and Oracle or MySQL from folks. It certainly looks like it may gain more ground.

Java 7 is awesome, and my favorite feature is clearly NIO2, reinforced at JavaOne. NIO2 brings static methods to interactions with external directory and file sources. It removes directories from the files class, which is long overdue. The nature of those static methods also happen to fit within the definition of Java code that lives inside the Oracle database and gives me a whole host of thoughts about potential in Oracle Database 12c.

Larry Ellison’s keynote was impressive because it gives us a clear vision of Oracle’s direction and Duncan Davies captured the keynote well in his blog. The continued presence of Red Hat and VMWare offers interesting reality checks to their key contributions to world wide implementation of the Oracle technical stack.

Issues that seem most critical to those I’ve chatted with are storage, security, tools, and development languages. A nice update on security can be found in the new edition of Hacking Exposed 7: Network Security Secrets & Solutions (7th Edition).

On the forthcoming Oracle 12c release, Information Week just released a good summary view. The introduction of the R programming language on the Exadata Server leads me to wonder about what uses may magically appears in Oracle Enterprise Manager down the road. The TIOBE Index for September 2012 doesn’t list the R language in the top 20 programming languages but there’s always the future. No mention of Erlang programming language at any of the conferences that I caught but it’s inevitably on the horizon as application servers evolve.

Now we wait for the Oracle Database 12c release, which looks like something in the very short term. Perhaps right after the holidays …

Written by maclochlainn

October 4th, 2012 at 12:30 pm

MySQL Workbench Book

with 2 comments

Finally, I finished writing the MySQL Workbench book. It’ll be available next spring. Now it’s time to leave for the plane, fly to San Francisco, and see everyone at MySQL Connect.

I look forward to meeting folks, I’ll be presenting after MySQL Connect for those staying for Oracle Open World. My presentation is at Oracle Develop on Monday, 10/1/12 from 16:45 – 17:45, in the Marriott Marquis – Foothill F. As I mentioned in an earlier post, you can probably catch me in Moscone West at the bookstore. The publisher requests we attend book signings. ;-)

Unfortunately as a speaker I need to convert my Keynote to Powerpoint, and had to purchase, install, and update Microsoft Office 2011 on my Mac. Open Office and Keynote weren’t on the approved list, alas …

Update: The book published 4/9/2013 (a bit of a delay from completing the write, eh?). It’s available on Safari as of yesterday.

Written by maclochlainn

September 28th, 2012 at 12:00 pm

Posted in MySQL,MySQL Workbench,Oracle

Tagged with ,

MySQL 5.0 migration bug

without comments

At present, you can’t use the MySQL Workbench migration tool to migrate MySQL 5.0 to MySQL 5.5, as documented in Bug 66861. The only documentation reference that I could find that references the mysql.proc table. Since the physical definition of the mysql.proc table changes across the MySQL 5.0, 5.1, and 5.6 releases, I modified my documentation Bug 66886 to suggest providing online documentation (as a feature request) for the mysql, information_schema, and performance_schema tables across all releases.

The actual definition of the mysql.proc table for MySQL 5.0.91 holds 16 columns not 20 columns as presently expected by the MySQL Workbench migration tool, and is summarized below:

Field Type Null Key
db char(64) NO PRI
name char(64) NO PRI
type enum(‘FUNCTION’,’PROCEDURE’) NO PRI
specific_name char(64) NO  
language enum(‘SQL’) NO SQL
sql_data_access enum(‘CONTAINS_SQL’,…) NO CONTAINS_SQL
is_deterministic enum(‘YES’,’NO’) NO NO
security_type enum(‘INVOKER’,’DEFINER’) NO DEFINER
param_list blob NO  
returns char(64) NO  
body longblob NO  
definer char(77) NO  
created timestamp NO CURRENT_TIMESTAMP
modified timestamp NO 0000-00-00 00:00:00
sql_mode set(‘REAL_AS_FLOAT’,…) NO  
comment char(64) NO  

I found out about the issue through a comment on my blog from Marc, who was trying to migrate his production instance. I hope this provides a heads-up to anybody else attempting to migrate a MySQL 5.0 database to a MySQL 5.5. The good news is that the MySQL Workbench team appears to be actively working the issue.

Written by maclochlainn

September 20th, 2012 at 12:47 am

Bulk Transfer Works

with 9 comments

As many already know, I’ve been trying to get the MySQL Workbench migration feature working between Microsoft SQL Server 2012 and MySQL 5.5. There are a number of features added to the 5.2.43 point release, and one led me to believe that the Migration tool expects to find the data in a schema of its own, as opposed to the dbo schema. Having made that change in Microsoft SQL Server, it did appear to have a positive impact on the migration and when I corrected a character set mismatch it worked perfectly!

MySQL Workbench successfully migrated the schema and table but failed to migrate the data because of a character set mismatch. I updated Bug 66516 the log file from the character set mismatch before I retyped all 9 test rows to make sure they were in a latin1 character set.

I shortened the original log file because the actual log had over 2,000 blanks line :-(. That’s probably something that should be fixed in the code too.

Starting...
Prepare information for data copy...
Prepare information for data copy done
Create shell script for data copy...
Table copy script written to C:\Users\McLaughlinM\Desktop\copy_migrated_tables.cmd
Create shell script for data copy done
Determine number of rows to copy....
Counting number of rows in tables...
 
wbcopytables.exe --count-only --passwords-from-stdin --odbc-source=DSN=SQL Server ODBC;DATABASE=;UID=sa --table [studentdb] [studentdb].[conquistador]
18:29:13 [INF][      copytable]: Opening ODBC connection to 'DSN=SQL Server ODBC;DATABASE=;UID=sa;PWD=XXX'
18:29:14 [INF][      copytable]: ODBC connection to 'DSN=SQL Server ODBC;DATABASE=;UID=sa;PWD=' opened
 
9 total rows in 1 tables need to be copied:
- [studentdb].[studentdb].[conquistador]: 9
Determine number of rows to copy finished
 
Copy data to target RDBMS....
 
Migrating data...
 
wbcopytables.exe --odbc-source=DSN=SQL Server ODBC;DATABASE=;UID=sa --target=student@mclaughlinsql:3306 --progress --passwords-from-stdin --thread-count=1 --table [studentdb] [studentdb].[conquistador] `studentdb` `conquistador` [conquistador_id], [conquistador], [actual_name], [nationality]
`studentdb`.`conquistador`:Copying 4 columns of 9 rows from table [studentdb].[studentdb].[conquistador]
 
ERROR: `studentdb`.`conquistador`:Inserting Batch: Incorrect string value: '\x9Acak' for column 'actual_name' at row 7
`studentdb`.`conquistador`:Finished copying 0 rows in 0m00s
 
29:15 [INF][      copytable]: Opening ODBC connection to 'DSN=SQL Server ODBC;DATABASE=;UID=sa;PWD=XXX'
29:16 [INF][      copytable]: ODBC connection to 'DSN=SQL Server ODBC;DATABASE=;UID=sa;PWD=' opened
29:16 [INF][      copytable]: Connecting to MySQL server at mclaughlinsql:3306 with user student
29:16 [INF][      copytable]: Connection to MySQL opened
 
Copy helper has finished
 
Data copy results:
- `studentdb`.`conquistador` has FAILED (0 of 9 rows copied)
0 tables of 1 were fully copied
 
Copy data to target RDBMS finished
Tasks finished with warnings and/or errors, view the logs for details
Finished performing tasks.

Originally, I thought the failure was due to the extended ASCII characters in the Microsoft SQL Server table. It still failed when I took all of the extended characters out. However, Alfredo suggested it was a character set issue, which is obvious when I looked more closely at the log – '\x9Acak' is clearly an incorrect string. I retyped the INSERT statement for the nine rows and it worked perfectly. Naturally, I’ve updated open Bug 66516 with the log file.

If you’re curious about the Microsoft SQL Server configuration check this post.

Written by maclochlainn

September 16th, 2012 at 6:55 pm

UTOUG Fall Symposium

without comments

Heading out to speak on Comparative SQL between Oracle and MySQL at the Utah Oracle User’s Group Fall Symposium. I’ll look forward to meeting old and new friends. Also, I’ve got a couple promotional copies of my Oracle Database 11g and MySQL 5.6 Developer Handbook to give out at the end of the session.

I’m also presenting Monday evening at Oracle Develop during Oracle Open World 2012. I’ll also have copies of the Oracle Database 11g PL/SQL Programming and Oracle Database 11g PL/SQL Programming Workbook books to give away at the end of the session. Naturally, McGraw-Hill wants me to stop by the bookstore for a signing. If you have time and are in Moscone West, stop by and visit.

Naturally, I’m also attending MySQL Connect to see the brilliant sessions being presented. Hope to see you in San Francisco! :-)

Written by maclochlainn

September 5th, 2012 at 1:56 pm

Posted in MySQL,Oracle