Oracle PL/SQL Tutorial/Collections/IS EMPTY

IS EMPTY Operator

You use the IS EMPTY operator to check if a nested table doesn"t contain elements. The following procedure, is_empty_example(), illustrates the use of IS EMPTY:

   <source lang="sql">

SQL> SQL> CREATE OR REPLACE PROCEDURE is_empty_example AS

 2    TYPE nestedTableType IS TABLE OF VARCHAR2(10);
 3    myTable1 nestedTableType;
 4    result BOOLEAN;
 5  BEGIN
 6    myTable1 := nestedTableType("F", "G", "S");
 7    result := myTable1 IS EMPTY;
 8    IF result THEN
 9      DBMS_OUTPUT.PUT_LINE("Nested table is empty");
10    ELSE
11      DBMS_OUTPUT.PUT_LINE("Nested table contains elements");
12    END IF;
13  END is_empty_example;
14  /

Procedure created. SQL> CALL is_empty_example(); Nested table contains elements Call completed. SQL> SQL></source>

IS EMPTY operator checks whether a VARRAY or NESTED TABLE collection variable is empty

   <source lang="sql">

SQL> SQL> DECLARE

 2     TYPE list IS TABLE OF INTEGER;
 3     a LIST := list();
 4   BEGIN
 5     IF a IS EMPTY THEN
 6       dbms_output.put_line(""a" is empty.");
 7     END IF;
 8   END;
 9   /

"a" is empty. PL/SQL procedure successfully completed. SQL></source>