Use the set_value v4 API method to describe to the consumer how many columns the result set has and how data should be read.
short set_value( void * arg_handle, a_sql_uint32 arg_num, an_extfn_value *value )
This method is used by the UDF in the _evaluate_extfn API. The UDF must call the set_value method to tell the consumer how many columns are in the result set and what set of a_v4_extfn_table_func functions the UDF supports.
For the set_value API, the UDF provides an appropriate arg_handle pointer via the _evaluate_extfnAPI, or from the args_handle member of a_v4_extfn_table_context structure.
The value argument for the set_value method must be of type DT_EXTFN_TABLE for v4 Table UDFs.
Parameter | Description |
---|---|
arg_handle | A context pointer provided by the consumer. |
arg_num | The index of the argument to set a value for. The only supported argument is 0. |
value | The value of the specified argument. |
1 if successful, 0 otherwise.