DESCRIBE

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DESCRIBE gathers information on the result-set or dynamic variable specifications in a prepared statement and places the information in an SQL descriptor area.

Usage

Embedded.

Description

Information concerning the prepared statement identified by statement-name is placed in the named SQL descriptor area.

The DESCRIBE statement and the DESCRIBE OUTPUT statement are equivalent, and gather information on the items in the result-set of the statement and places it in the SQL descriptor area.

The DESCRIBE INPUT statement describes the statement's input and output variables.

The DESCRIBE OUTPUT statement describes the result-set returned by the statement (a SELECT or a CALL to a result set procedure).

If descriptions of both the result set and the input variables are required for a prepared statement, the statement must be described separately with each form of DESCRIBE.

The descriptor-name is identified by a host variable or a literal.

WITHOUT NESTING is implicit. If NESTING is specified, a structured user-defined type will result in a subordinate descriptor, which means that the structured type's attributes will be be included in the description.

See ALLOCATE DESCRIPTOR for a description of the SQL descriptor area.

See ALLOCATE CURSOR for a description of extended statements.

See also, GET DESCRIPTOR.

Restrictions

The DESCRIBE statement is only applicable to dynamically prepared SQL statements.

Examples

 exec sql ALLOCATE DESCRIPTOR 'DescrIn';
 exec sql ALLOCATE DESCRIPTOR 'DescrOut';
 sqlstr = 'SELECT * FROM tab1 WHERE col1 = ? and col2 = ?';
 exec sql PREPARE 'stmt X1' FROM :sqlstr;
 exec sql DESCRIBE INPUT 'stmt X1' USING SQL DESCRIPTOR 'DescrIn';
 exec sql DESCRIBE OUTPUT 'stmt X1' USING SQL DESCRIPTOR 'DescrOut';
 
 sqlstr = 'CALL proc(?, ?, ?)';
 exec sql PREPARE stmt2 FROM :sqlstr;
 exec sql DESCRIBE INPUT stmt2 USING SQL DESCRIPTOR :SQLA1;
 

For more information, see the Mimer SQL Programmer's Manual, Describing Prepared Statements.

Standard Compliance

Standard	Compliance	Comments
SQL-2011	Features outside core	Feature B031, "Basic dynamic SQL".

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