Statement Terminators

Some SQL statement editors — specifically the isql utility that comes with Firebird, and possibly some third-party editors — employ an internal convention that requires all statements to be terminated with a semicolon.This creates a conflict with PSQL syntax when coding in these environments.If you are unacquainted with this problem and its solution, please study the details in the PSQL chapter in the section entitled Switching the Terminator in isql.

Parameters

Each parameter has a data type.The NOT NULL constraint can also be specified for any parameter, to prevent NULL being passed or assigned to it.

A collation can be specified for string-type parameters, using the COLLATE clause.

Input Parameters: Input parameters are presented as a parenthesized list following the name of the function.They are passed by value into the procedure, so any changes inside the procedure has no effect on the parameters in the caller.Input parameters may have default values.Parameters with default values specified must be added at the end of the list of parameters.
Output Parameters: The optional RETURNS clause is for specifying a parenthesised list of output parameters for the stored procedure.