SQL Language Extension: default paremeters in stored procedures Function: allow input parameters of stored procedures to have optional default values Autor: Vlad Khorsun <hvlad at users.sourceforge.net> Syntax: same as default value definition of column or domain, except that you can use '=' in place of 'DEFAULT' keyword. Parameters with default values must be last in parameter list i.e. not allowed to define parameter without default value after parameter with default value. Caller must set first few parameters, i.e. not allowed set param1, param2, miss param3, set param4... Default values substitution occurs at run-time. If you define procedure with defaults (say P1), call it from another procedure (say P2) and skip some last parameters (with default value) then default values for P1 will be substituted by the engine at time of the beginning of execution P1. Then if you change default values for P1 it is not need to recompile P2. But it is still necessary to disconnect all client connections, for more details see IB6 Beta documentation "Data Definition Guide", section "Altering and dropping procedures in use" Examples: CONNECT ... ; CREATE PROCEDURE P1 (X INTEGER = 123) RETURNS (Y INTEGER) AS BEGIN Y = X; SUSPEND; END; COMMIT; SELECT * FROM P1; Y ============ 123 EXECUTE PROCEDURE P1; Y ============ 123 CREATE PROCEDURE P2 RETURNS (Y INTEGER) AS BEGIN FOR SELECT Y FROM P1 INTO :Y DO SUSPEND; END; COMMIT; SELECT * FROM P2; Y ============ 123 ALTER PROCEDURE P1 (X INTEGER = CURRENT_TRANSACTION) RETURNS (Y INTEGER) AS BEGIN Y = X; SUSPEND; END; COMMIT; SELECT * FROM P1; Y ============ 5875 SELECT * FROM P2; Y ============ 123 COMMIT; CONNECT ... ; SELECT * FROM P2; Y ============ 5880 Notes: default sources and BLR's are kept in RDB$FIELDS