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
3-37
Date-Time and Interval Data
Selecting SQL/MP DATETIME Values Not Equivalent to
DATE, TIME, or TIMESTAMP
To retrieve nonstandard SQL/MP DATETIME values that are not equivalent to DATE,
TIME, or TIMESTAMP, declare a C char array one character larger than the number of
characters you expect to store in the array. For a list of nonstandard SQL/MP
DATETIME data types, see the SQL/MX Reference Manual.
Use the SQL/MX CAST function to convert a date-time column in a select list to a
character string. You must also specify the length in the AS clause of the CAST
function to be the length of the declared host variable minus 1. Append a null
terminator to the output character string before you process it as a C character string.
Example
Suppose that an SQL/MP database has a BILLINGS table that consists of the
CUSTNUM and BILLING_DATE columns. The BILLING_DATE column has a
DATETIME MONTH TO DAY data type, which has no equivalent in SQL/MX. This
example selects the SQL/MP DATETIME value:
EXEC SQL BEGIN DECLARE SECTION;
struct billing_rec {
unsigned short hv_custnum;
char hv_billing_date[6];
...
} bill;
...
EXEC SQL END DECLARE SECTION;
...
EXEC SQL SELECT custnum, CAST(billing_date AS CHAR(5))
INTO :bill.hv_custnum, :bill.hv_billing_date
FROM billings
WHERE custnum = :hv_this_customer;
... bill.hv_billing_date[5]='\0';
Inserting or Updating SQL/MP DATETIME Values Not
Equivalent to DATE, TIME, or TIMESTAMP
To insert or update nonstandard SQL/MP DATETIME values that are not equivalent to
DATE, TIME, or TIMESTAMP, format a C character string in the desired display format
for a date, time, or timestamp. Within an INSERT or UPDATE statement, use the
SQL/MX CAST function to convert the character date-time data to a DATE, TIME, or
TIMESTAMP data type.
If you are using date-time values as input values to the database in statements other
than INSERT or UPDATE (for example, within the WHERE clause of a SELECT
statement), you must also use the CAST function to convert the character string to a
DATE, TIME, or TIMESTAMP data type.
C