MacLochlainns Weblog

-- 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;
/

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;
/