In order to accomplish this, we will make use of NULL indicator after the SELECT query on the INVOICE_ID of the ORDERS table. If the NULL indicator has the value as -1 then we can conclude that INVOIVE_ID has a null value.
Below is a COBOL paragraph for this−
A010-CHECK-ORDER. EXEC SQL SELECT INVOICE_ID INTO :INVOICE_ID_DATA :INVOICE_ID_N FROM ORDERS WHERE ORDER_ID = ‘678542112’ END-EXEC IF INVOICE-ID-N = -1 MOVE SPACES TO INVOICE-ID-DATA END-IF
INVOICE-ID-N is a null indicator here which is generated automatically by DCLGEN utility.