SQL/MX 3.2.1 Programming Manual for C and COBOL (H06.26+, J06.15+)

Host Variables in C/C++ Programs

HP NonStop SQL/MX Release 3.2.1 Programming Manual for C and COBOL—663854-005

3-35

Date-Time and Interval Data

DATE Representation

You can insert or retrieve date-time values in any of three formats, independently of the

SQL column definition. For example, you can specify formats such as 09/15/1993,

1993-09-15, or 15.09.1993. You control the display format by inserting the value in the

format you want and retrieving the value by using the DATEFORMAT function. See the

DATEFORMAT function in the SQL/MX Reference Manual.

For example, if a table in the database has this column definition:

HIRE_DATE DATE

The host variable representation for December 22, 1988, in DEFAULT format is:

A DATE host variable in DEFAULT format is represented as an 11-character string,

including 10 characters—with hyphens (-) as field separators—plus a character (empty

space) for a null terminator.

Selecting Standard Date-Time Values

To retrieve standard date-time values (DATE, TIME, or TIMESTAMP, or the SQL/MP

DATETIME equivalents) from the database, declare a date-time (DATE, TIME, or

TIMESTAMP) host variable. For the required number of digits for DATE, TIME, or

TIMESTAMP values, see Table 3-3 on page 3-11.

If your C program performs string operations on the date-time host variable, you must

append a null terminator to the output string before processing it because the date-time

data types are internally processed as C character strings.

Table 3-7

lists the lengths of the target arrays for TIME and TIMESTAMP values, which

depend on the precision (the number of digits in the fractional seconds).

Table 3-7. Lengths of C Target Arrays for TIME and TIMESTAMP

TIME Precision Length TIMESTAMP Precision Length

TIME 9 TIMESTAMP 27

TIME(0) 9 TIMESTAMP(0) 20

TIME(1) 11 TIMESTAMP(1) 22

TIME(2) 12 TIMESTAMP(2) 23

TIME(3) 13 TIMESTAMP(3) 24

TIME(4) 14 TIMESTAMP(4) 25

TIME(5) 15 TIMESTAMP(5) 26

TIME(6) 16 TIMESTAMP(6) 27

1 9 8 8 1 2 2 2



Year Separator Month Separator Day

Null