Oracle PL/SQL Loops Please use speaker notes for additional information!

DECLARE v_recno testloop.rec_no%TYPE :=1; v_ctr testloop.ctr%TYPE :=100; BEGIN LOOP INSERT INTO testloop(rec_no, ctr) VALUES(v_recno, v_ctr); v_recno :=v_recno + 1; v_ctr := v_ctr + 10; IF v_recno > 5 THEN EXIT; END IF; END LOOP; END; / SQL> edit basicloop1 Basic loop SYNTAX: LOOP Processing code within the loop EXIT (which can include a WHEN condition) END LOOP; SQL> SELECT * FROM testloop; REC_NO CTR DATA_IN basicloop1 PL/SQL procedure successfully completed. PL/SQL code for the basicloop1 block (as seen in the editor).

DECLARE v_recno testloop.rec_no%TYPE :=1; v_ctr testloop.ctr%TYPE :=100; BEGIN LOOP INSERT INTO testloop(rec_no, ctr) VALUES(v_recno, v_ctr); v_recno :=v_recno + 1; v_ctr := v_ctr + 10; IF v_recno > 5 THEN EXIT; END IF; END LOOP; END; / Pass Rows in testloop v_recno v_ctr test v_recno > 5 Initialize Pass > 5 = NO - LOOP Pass > 5 = NO - LOOP Pass > 5 = NO - LOOP Pass > 5 = NO - LOOP Pass > 5 = YES - EXIT Basic loop

DECLARE v_recno testloop.rec_no%TYPE :=1; v_ctr testloop.ctr%TYPE :=100; BEGIN LOOP INSERT INTO testloop(rec_no, ctr) VALUES(v_recno, v_ctr); v_recno :=v_recno + 1; v_ctr := v_ctr + 10; EXIT WHEN v_recno > 5 END LOOP; END; / Pass Rows in testloop v_recno v_ctr test v_recno > 5 Initialize Pass > 5 = NO - LOOP Pass > 5 = NO - LOOP Pass > 5 = NO - LOOP Pass > 5 = NO - LOOP Pass > 5 = YES - EXIT Basic loop

Basicloop1 v_recno = 1 v_ctr = 100 Loop Insert v_recno, v_ctr into testloop Add 1 to v_recno Add 1 to v_ctr v_recno NOT > 5 END Basicloop1 Loop Y N Pass Rows in testloop v_recno v_ctr test v_recno NOT > 5 Initialize Pass NOT> 5 = NO - LOOP Pass NOT > 5 = NO - LOOP Pass NOT > 5 = NO - LOOP Pass NOT > 5 = NO - LOOP Pass > 5 = YES - EXIT Exit drops to END processing complete END has been reached - processing complete END Directions: Click to initialize and then click to see each of the passes. The last message will tell you processing is complete.

While loops DECLARE v_recno testloop.rec_no%TYPE :=1; v_ctr testloop.ctr%TYPE :=100; BEGIN WHILE v_recno < 6 LOOP INSERT INTO testloop(rec_no, ctr) VALUES(v_recno, v_ctr); v_recno :=v_recno + 1; v_ctr := v_ctr + 10; END LOOP; END; / SQL> edit whileloop1 whileloop1 PL/SQL procedure successfully completed. SQL> SELECT * FROM testloop; REC_NO CTR DATA_IN SYNTAX: WHILE condition LOOP processing code END LOOP;

While loops DECLARE v_recno testloop.rec_no%TYPE :=1; v_ctr testloop.ctr%TYPE :=100; BEGIN WHILE v_recno < 6 LOOP INSERT INTO testloop(rec_no, ctr) VALUES(v_recno, v_ctr); v_recno :=v_recno + 1; v_ctr := v_ctr + 10; END LOOP; END; / Pass test v>recno recno < 6 rows in testloop v_recno v_ctr Initialize Pass 1 1 < 6 is YES - LOOP Pass 2 2 < 6 is YES - LOOP Pass 3 3 < 6 is YES - LOOP Pass 4 4 < 6 is YES - LOOP Pass 5 5 < 6 is YES - LOOP Pass 6 6 < 6 is NO - END LOOP (processing is not executed)

v_recno < 6 Y N Whileloop1 v_recno = 1 v_ctr = 100 LOOP END Whileloop1 END Insert v_recno, v_ctr into testloop Add 1 to v_recno Add 1 to v_ctr LOOP END LOOP While loop This flowchart shows the loop code in a separate module. If v_recno <6 the loop is executed. Then the control returns to ask the question again. If the answer to v_recno <6 is No, then the loop is not performed and the END is executed since there is no code except END after the loop. The dotted lines would not be included in the flowchart - I put them in to show the flow.

v_recno < 6 Y N Whileloop1 v_recno = 1 v_ctr = 100 LOOP END Whileloop1 END Insert v_recno, v_ctr into testloop Add 1 to v_recno Add 1 to v_ctr LOOP END LOOP While loop Pass test v>recno recno < 6 rows in testloop v_recno v_ctr Initialize Pass 1 1 < 6 is YES - LOOP Pass 2 2 < 6 is YES - LOOP Pass 3 3 < 6 is YES - LOOP Pass 4 4 < 6 is YES - LOOP Pass 5 5 < 6 is YES - LOOP Pass 6 6 < 6 is NO - END LOOP (processing is not executed) Directions: Click to initialize and then click to see each of the passes. The last message will tell you processing is complete. processing complete END has been reached - processing complete

While loop Whileloop1 v_recno = 1 v_ctr = 100 Loop Insert v_recno, v_ctr into testloop Add 1 to v_recno Add 1 to v_ctr END Whileloop1 END End Loop v_recno NOT < 6 Y N End Loop Pass test v>recno recno < 6 rows in testloop v_recno v_ctr Initialize Pass 1 1 < 6 is YES - LOOP Pass 2 2 < 6 is YES - LOOP Pass 3 3 < 6 is YES - LOOP Pass 4 4 < 6 is YES - LOOP Pass 5 5 < 6 is YES - LOOP Pass 6 6 < 6 is NO - END LOOP (processing is not done)

For loop SYNTAX: FOR index in [REVERSE] lower_bound..upper_bound LOOP processing code END LOOP; DECLARE v_recno testloop.rec_no%TYPE :=1; v_ctr testloop.ctr%TYPE :=100; BEGIN FOR i IN 1..5 LOOP INSERT INTO testloop(rec_no, ctr) VALUES(v_recno, v_ctr); v_recno :=v_recno + 1; v_ctr := v_ctr + 10; END LOOP; END; / SQL> edit forloop1 SQL> SELECT * FROM testloop; REC_NO CTR DATA_IN PL/SQL procedure successfully completed.

For loop DECLARE v_recno testloop.rec_no%TYPE :=1; v_ctr testloop.ctr%TYPE :=100; BEGIN FOR i IN 1..5 LOOP INSERT INTO testloop(rec_no, ctr) VALUES(v_recno, v_ctr); v_recno :=v_recno + 1; v_ctr := v_ctr + 10; END LOOP; END; / Pass i range 1 to 5 rows in testloop v_recno v_ctr Initialize Pass 1 i = 1 - LOOP Pass 2 i = 2 - LOOP Pass 3 i = 3 - LOOP Pass 4 i = 4 - LOOP Pass 5 i = 5 - LOOP Maximum value i has been reached - END LOOP (processing is not done)