An SQLDA is a set of variables that is required for execution of the SQL DESCRIBE statement, and it may optionally be used by the PREPARE, OPEN, CALL, FETCH, and EXECUTE statements. An SQLDA can be used in a DESCRIBE statement, altered with the addresses of host variables, and then used again in a FETCH statement.
SQLDAs are supported for all languages, but predefined declarations are provided only for C (and C++), COBOL, ILE RPG/400, PL/I, and REXX. In REXX, the SQLDA is somewhat different than in the other languages; for information on the use of SQLDAs in REXX, see the SQL Programming with Host Languages book.
The meaning of the information in an SQLDA depends on its use. In PREPARE and DESCRIBE, an SQLDA provides information to an application program about a prepared statement. In OPEN, CALL, EXECUTE, and FETCH, an SQLDA provides information to the database manager about host variables.