DBMS_SQL

• You are advised to use dbms_sql.define_column and dbms_sql.column_value to define columns.
• If the size of the result set is greater than the value of work_mem, the result set will be flushed to disk. The value of work_mem must be no greater than 512 MB.

• DBMS_SQL.OPEN_CURSOR

  This function opens a cursor and is the prerequisite for the subsequent dbms_sql operations. This function does not transfer any parameter. It automatically generates cursor IDs in an ascending order and returns values to integer variables.

  The function prototype of DBMS_SQL.OPEN_CURSOR is:
• DBMS_SQL.CLOSE_CURSOR

  This function closes a cursor. It is the end of each dbms_sql operation. If this function is not invoked when the stored procedure ends, the memory is still occupied by the cursor. Therefore, remember to close a cursor when you do not need to use it. If an exception occurs, the stored procedure exits but the cursor is not closed. Therefore, you are advised to include this interface in the exception handling of the stored procedure.

  The function prototype of DBMS_SQL.CLOSE_CURSOR is:

  Table 2 DBMS_SQL.CLOSE_CURSOR interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be closed

• DBMS_SQL.PARSE

  This function parses the query statement of a given cursor. The input query statement is executed immediately. Currently, only the SELECT query statement can be parsed. The statement parameters can be transferred only through the TEXT type. The length cannot exceed 1 GB.

  The function prototype of DBMS_SQL.PARSE is:

  Table 3 DBMS_SQL.PARSE interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor whose query statement is parsed
  query_string	Query statements to be parsed
  language_flag	Version language number. Currently, only 1 is supported.

• DBMS_SQL.EXECUTE

  This function executes a given cursor. This function receives a cursor ID. The obtained data after is used for subsequent operations. Currently, only the SELECT query statement can be executed.

  The function prototype of DBMS_SQL.EXECUTE is:

  Table 4 DBMS_SQL.EXECUTE interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor whose query statement is parsed

• DBMS_SQL.FETCHE_ROWS

  This function returns the number of data rows that meet query conditions. Each time the interface is executed, the system obtains a set of new rows until all data is read.

  The function prototype of DBMS_SQL.FETCHE_ROWS is:

  Table 5 DBMS_SQL.FETCH_ROWS interface parameters

  Parameter Name	Description
  curosorid	ID of the cursor to be executed

• DBMS_SQL.DEFINE_COLUMN

  This function defines columns returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

  The function prototype of DBMS_SQL.DEFINE_COLUMN is:

  Table 6 DBMS_SQL.DEFINE_COLUMN interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  column_ref	Variable of any type. You can select an appropriate interface to dynamically define columns based on variable types.
  column_size	Length of a defined column

• DBMS_SQL.DEFINE_COLUMN_CHAR

  This function defines columns of the CHAR type returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

  The function prototype of DBMS_SQL.DEFINE_COLUMN_CHAR is:

  Table 7 DBMS_SQL.DEFINE_COLUMN_CHAR interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  column	Parameter to be defined
  column_size	Length of a dynamically defined column

• DBMS_SQL.DEFINE_COLUMN_INT

  This function defines columns of the INT type returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

  The function prototype of DBMS_SQL.DEFINE_COLUMN_INT is:

  Table 8 DBMS_SQL.DEFINE_COLUMN_INT interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query

• DBMS_SQL.DEFINE_COLUMN_LONG

  This function defines columns of a long type (not LONG) returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type. The maximum size of a long column is 1 GB.

  The function prototype of DBMS_SQL.DEFINE_COLUMN_LONG is:

  Table 9 DBMS_SQL.DEFINE_COLUMN_LONG interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query

• DBMS_SQL.DEFINE_COLUMN_RAW

  This function defines columns of the RAW type returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

  The function prototype of DBMS_SQL.DEFINE_COLUMN_RAW is:

  Table 10 DBMS_SQL.DEFINE_COLUMN_RAW interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  column	Parameter of the RAW type
  column_size	Column length

• DBMS_SQL.DEFINE_COLUMN_TEXT

  This function defines columns of the TEXT type returned from a given cursor and can be used only for the cursors defined by SELECT. The defined columns are identified by the relative positions in the query list. The data type of the input variable determines the column type.

  The function prototype of DBMS_SQL.DEFINE_COLUMN_TEXT is:

  Table 11 DBMS_SQL.DEFINE_COLUMN_TEXT interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  max_size	Maximum length of the defined TEXT type

• DBMS_SQL.DEFINE_COLUMN_UNKNOWN

  This function processes columns of unknown data types returned from a given cursor and is used only for the system to report an error and exist when the type cannot be identified.

  The function prototype of DBMS_SQL.DEFINE_COLUMN_UNKNOWN is:

  Table 12 DBMS_SQL.DEFINE_COLUMN_UNKNOWN interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  column	Dynamically defined parameter

• DBMS_SQL.COLUMN_VALUE

  This function returns the cursor element value specified by a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

  The function prototype of DBMS_SQL.COLUMN_VALUE is:

  Table 13 DBMS_SQL.COLUMN_VALUE interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  column_value	Return value of a defined column

• DBMS_SQL.COLUMN_VALUE_CHAR

  This function returns the value of the CHAR type in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

  The function prototype of DBMS_SQL.COLUMN_VALUE_CHAR is:

  Table 14 DBMS_SQL.COLUMN_VALUE_CHAR interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  column_value	Return value
  err_num	Error No. It is an output parameter and the argument must be a variable. Currently, the output value is –1 regardless of the argument.
  actual_length	Length of a return value

• DBMS_SQL.COLUMN_VALUE_INT
  This function returns the value of the INT type in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS. The function prototype of DBMS_SQL.COLUMN_VALUE_INT is:

  Table 15 DBMS_SQL.COLUMN_VALUE_INT interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query

• DBMS_SQL.COLUMN_VALUE_LONG

  This function returns the value of a long type (not LONG or BIGINT) in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

  The function prototype of DBMS_SQL.COLUMN_VALUE_LONG is:

  Table 16 DBMS_SQL.COLUMN_VALUE_LONG interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  length	Length of a return value
  off_set	Start position of a return value
  column_value	Return value
  actual_length	Length of a return value

• DBMS_SQL.COLUMN_VALUE_RAW

  This function returns the value of the RAW type in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

  The function prototype of DBMS_SQL.COLUMN_VALUE_RAW is:

  Table 17 DBMS_SQL.COLUMN_VALUE_RAW interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  column_value	Returned column value
  err_num	Error No. It is an output parameter and the argument must be a variable. Currently, the output value is –1 regardless of the argument.
  actual_length	Length of a return value. The value longer than this length will be truncated.

• DBMS_SQL.COLUMN_VALUE_TEXT

  This function returns the value of the TEXT type in a specified position of a cursor and accesses the data obtained by DBMS_SQL.FETCH_ROWS.

  The function prototype of DBMS_SQL.COLUMN_VALUE_TEXT is:

  Table 18 DBMS_SQL.COLUMN_VALUE_TEXT interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query

• DBMS_SQL.COLUMN_VALUE_UNKNOWN

  This function returns the value of an unknown type in a specified position of a cursor. This is an error handling interface when the type is not unknown.

  The function prototype of DBMS_SQL.COLUMN_VALUE_UNKNOWN is:

  Table 19 DBMS_SQL.COLUMN_VALUE_UNKNOWN interface parameters

  Parameter Name	Description
  cursorid	ID of the cursor to be executed
  position	Position of a dynamically defined column in the query
  column_type	Returned parameter type

• DBMS_SQL.IS_OPEN

This function returns the status of a cursor: open, parse, execute, or define. The value is TRUE. If the status is unknown, an error is reported. In other cases, the value is FALSE.