The EXTFNAPIV4_DESCRIBE_PARM_TABLE_NUM_COLUMNS attribute indicates the number of columns in the table. Used in a describe_parameter_set scenario.
a_sql_uint32
The number of columns in the table. Only valid for argument 0 and table arguments.
If the UDF sets this property, the server compares the value with the name of the parameter supplied in the CREATE PROCEDURE statement. If the two values do not match, the server returns an error. This allows the UDF to ensure the CREATE PROCEDURE statement has the same parameter names as the UDF is expecting.
On success, returns the sizeof(a_sql_uint32).