Called by a copy of a table function that does not want to participate in the process of returning rows.
| IF the call is … | THEN FNC_TblOptOut returns … |
|---|---|
| successful | 0. |
| not successful | -1. This can happen when a table function calls FNC_TblOptOut in the wrong mode or phase. |
Use this library function when the return value of FNC_GetPhase is TBL_MODE_CONST, indicating that the SELECT statement invoked the table function with constant expression input arguments.
For example:
SELECT *
FROM TABLE (table_function_1('STRING_CONSTANT'))
AS table_1;
Syntax
int FNC_TblOptOut(void)
Usage Notes
If every copy of the table function calls FNC_TblOptOut, then the step ends as if no rows are created and the result is an empty derived table.
This function can only be called from within a table function. Calling this function from a scalar function, aggregate function, UDM, or external stored procedure results in an exception on the transaction.
- return value of TBL_MODE_CONST for the mode
- value of TBL_PRE_INIT or TBL_INIT for the processing phase
A table function can call FNC_TblOptOut only once.
Example Using FNC_TblOptOut
FNC_Phase Phase;
if (FNC_GetPhase(&Phase) == TBL_MODE_CONST)
{
switch(Phase)
{
case TBL_PRE_INIT:
switch (FNC_Tbl_FirstParticipant() )
{
case 1: /* participant */
return;
case 0: /* not participant */
if (FNC_TblOptOut())
strcpy(sqlstate, "U0006"); /* an error return */
return;
default: /* -1 or other error */
strcpy(sqlstate, "U0007");
return;
}
...
}
...
}