Macros for datetime and interval data types
In addition to the datetime and interval data
structures, the datetime.h file defines the macro
functions shown in the following table for working directly with qualifiers
in binary form.
| Name of Macro | Description |
|---|---|
| TU_YEAR | Time unit for the YEAR qualifier field |
| TU_MONTH | Time unit for the MONTH qualifier field |
| TU_DAY | Time unit for the DAY qualifier field |
| TU_HOUR | Time unit for the HOUR qualifier field |
| TU_MINUTE | Time unit for the MINUTE qualifier field |
| TU_SECOND | Time unit for the SECOND qualifier field |
| TU_FRAC | Time unit for the leading qualifier field of FRACTION |
| TU_Fn | Names for datetime ending fields of FRACTION(n), for n from 1 - 5 |
| TU_START(q) | Returns the leading field number from qualifier q |
| TU_END(q) | Returns the trailing field number from qualifier q |
| TU_LEN(q) | Returns the length in digits of the qualifier q |
| TU_FLEN(f) | Returns the length in digits of the first field, f, of an interval qualifier |
| TU_ENCODE(p,f,t) | Creates a qualifier from the first field number f with precision p and trailing field number t |
| TU_DTENCODE(f,t) | Creates a datetime qualifier from the first field number f and trailing field number t |
| TU_IENCODE(p,f,t) | Creates an interval qualifier from the first field number f with precision p and trailing field number t |
For example, if your program does not provide an interval qualifier
in the host-variable declaration, you need to use the interval qualifier
macros to initialize and set the interval host variable. In
the following example, the interval variable gets a day
to second qualifier. The precision of the largest field in the
qualifier, day, is set to
2:/* declare a host variable without a qualifier */
EXEC SQL BEGIN DECLARE SECTION;
interval inv1;
EXEC SQL END DECLARE SECTION;
/* set the interval qualifier for the host variable */
inv1.in_qual = TU_IENCODE(2, TU_DAY, TU_SECOND);
/* assign values to the host variable */
incvasc ("5 2:10:02", &inv1);