Before calling FNC_GetDistinctValue, you must allocate the buffer pointed to by returnValue using the C data type that maps to the underlying type of the distinct UDT. For example, if the distinct type represents an SQL INTEGER data type, declare the buffer like this:
INTEGER value;
If the underlying type of the distinct UDT is a character string, FNC_GetDistinctValue returns a null-terminated character string. The buffer you define must be large enough to accommodate null termination.
For information on the C data types that you can use, see C Data Types.
To guarantee that the value you pass in for the bufSize argument matches the length of the data type, use the following macros defined in the sqltypes_td.h header file.
| Macro | Description |
|---|---|
SIZEOF_CHARACTER_LATIN_WITH_NULL(len) SIZEOF_CHARACTER_KANJISJIS_WITH_NULL(len) SIZEOF_CHARACTER_KANJI1_WITH_NULL(len) SIZEOF_CHARACTER_UNICODE_WITH_NULL(len) |
Returns the length in bytes of a CHARACTER data type of len characters, including null termination characters. For example, the following returns a length of 8 (3 * 2 + 2 = 8):SIZEOF_CHARACTER_UNICODE_WITH_NULL(3) |
SIZEOF_VARCHAR_LATIN_WITH_NULL(len) SIZEOF_VARCHAR_KANJISJIS_WITH_NULL(len) SIZEOF_VARCHAR_KANJI1_WITH_NULL(len) SIZEOF_VARCHAR_UNICODE_WITH_NULL(len) |
Returns the length in bytes of a VARCHAR data type of len characters, including null termination characters. For example, the following returns a length of 8 (3 * 2 + 2 = 8):SIZEOF_VARCHAR_UNICODE_WITH_NULL(3) |
SIZEOF_BYTE(len) SIZEOF_VARBYTE(len) |
Returns the length in bytes of the specified BYTE or VARBYTE data type, where len specifies the number of values. |
SIZEOF_GRAPHIC(len) SIZEOF_VARGRAPHIC(len) |
Returns the length in bytes of the specified CHARACTER(n) CHARACTER SET GRAPHIC or VARCHAR(n) CHARACTER SET GRAPHIC data type, where len specifies the number of values. |
SIZEOF_BYTEINT SIZEOF_SMALLINT SIZEOF_INTEGER SIZEOF_BIGINT SIZEOF_REAL SIZEOF_DOUBLE_PRECISION SIZEOF_FLOAT SIZEOF_DECIMAL1 SIZEOF_DECIMAL2 SIZEOF_DECIMAL4 SIZEOF_DECIMAL8 SIZEOF_DECIMAL16 SIZEOF_NUMERIC1 SIZEOF_NUMERIC2 SIZEOF_NUMERIC4 SIZEOF_NUMERIC8 SIZEOF_NUMERIC16 SIZEOF_NUMBER |
Returns the length in bytes of the specified numeric data type. For NUMBER, the length returned is 4 + 2 + 17 = 23 bytes since Vantage allocates max length (17 bytes) for the mantissa. |
SIZEOF_DATE SIZEOF_ANSI_Time SIZEOF_ANSI_Time_WZone SIZEOF_TimeStamp SIZEOF_TimeStamp_WZone |
Returns the length in bytes of the specified DateTime type. |
SIZEOF_INTERVAL_YEAR SIZEOF_IntrvlYtoM SIZEOF_INTERVAL_MONTH SIZEOF_INTERVAL_DAY SIZEOF_IntrvlDtoH SIZEOF_IntrvlDtoM SIZEOF_IntrvlDtoS SIZEOF_HOUR SIZEOF_IntrvlHtoM SIZEOF_IntrvlHtoS SIZEOF_MINUTE SIZEOF_IntrvlMtoS SIZEOF_IntrvlSec |
Returns the length in bytes of the specified Interval type. |