References to procedures

Stored Procedures are invoked from the CALL statement where they are referenced by a qualified name (schema and stored procedure name), followed by a list of arguments enclosed by parentheses. A stored procedure can also be invoked without the schema name, resulting in a choice of possible stored procedures in different schemas with the same number of parameters.

Each parameter passed to the stored procedure can be composed of a host variable, parameter marker, expression, or NULL. The following are restrictions for stored procedure parameters:

OUT and INOUT parameters must be host variables.
NULLs cannot be passed to Java™ stored procedures unless the SQL data type maps to a Java class type.
NULLs cannot be passed to PARAMETER STYLE GENERAL stored procedures.

The position of the arguments is important and must conform to the stored procedure definition for the semantics to be correct. Both the position of the arguments and the stored procedure definition must conform to the stored procedure body itself. The database manager does not attempt to shuffle arguments to better match a stored procedure definition, and the database manager do not understand the semantics of the individual stored procedure parameters.