Oracle PL/SQL/Data Type/IS NULL Value

If value IS NULL, raise exception

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SQL> SQL> DECLARE

 2     lv_general_excep EXCEPTION;
 3  BEGIN
 4     IF NULL IS NULL THEN
 5        RAISE lv_general_excep;
 6     ELSE
 7        -- Process Logic
 8        NULL;
 9     END IF;
10  EXCEPTION
11     WHEN lv_general_excep THEN
12        NULL;
13  END;
14  /

PL/SQL procedure successfully completed. SQL>

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The IS NULL operator in action

   <source lang="sql">

SQL> SQL> -- The IS NULL operator in action. SQL> SET SERVEROUTPUT ON SQL> DECLARE

 2     test  INTEGER;
 3  BEGIN
 4     --the variable TEST is currently null because
 5     -- a value hasn"t been assigned to it yet.
 6     IF test IS NULL THEN
 7       DBMS_OUTPUT.PUT_LINE("The variable TEST is null.");
 8     END IF;
 9     --Assign a value to TEST and display it.
10     test := 1;
11     DBMS_OUTPUT.PUT_LINE("TEST = " || TO_CHAR(test));
12     --Test is no longer null because a value has been assigned to it.
13     IF test IS NOT NULL THEN
14          DBMS_OUTPUT.PUT_LINE("The variable TEST is NOT null.");
15     END IF;
16  END;
17  /

The variable TEST is null. TEST = 1 The variable TEST is NOT null. PL/SQL procedure successfully completed. SQL>

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