SQL/MX Programming Manual for C and COBOL (G06.24+, H06.03+)

Host Variables in COBOL Programs
HP NonStop SQL/MX Programming Manual for C and COBOL—523627-004
4-20
Testing for Null or a Truncated Value
MOVE -1 TO RETIRE-IND.
EXEC SQL
INSERT INTO persnl.retirees
VALUES (:NEW-EMPNUM,:RETIRE-DATE INDICATOR :RETIRE-IND)
END-EXEC.
...
This example uses the NULL keyword instead of an indicator variable to insert the null
value:
...
EXEC SQL
INSERT INTO persnl.retirees VALUES (:NEW-EMPNUM, NULL)
END-EXEC.
Testing for Null or a Truncated Value
To test for null or a truncated character value, check the indicator variable associated
with a host variable. If the value of the indicator variable is less than zero, the
associated column contains null. If the value of the indicator variable is greater than
zero, character data in the column was truncated when it was assigned to the host
variable.
Example
A database contains a PRODUCTS table that includes the columns PRODNUM and
TIMESTAMP_SHIPPED (which allows null). Example 4-1 on page 4-21 selects data
from the PRODUCTS table and then tests for null by using the indicator variable SHIP-
IND. If the value of the indicator variable is less than 0 (zero), the associated column
contains a null value.