в 13:45, 26 мая 2010

2010-05-26T13:45:19Z

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2010-05-26T09:59:33Z

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==An anonymous block demonstrates a guard on exit simple loop==



<source lang="sql">

SQL>
SQL> DECLARE
2 counter NUMBER;
3 first BOOLEAN;
4 BEGIN
5 LOOP
6 IF NVL(counter,1) >= 1 THEN
7 IF NOT NVL(first,TRUE) THEN
8 counter := counter + 1;
9 ELSE
10 counter := 1;
11 first := FALSE;
12 END IF;
13 END IF;
14 dbms_output.put_line("Iteration ["||counter||"]");
15
16 EXIT WHEN NOT counter < 3;
17 END LOOP;
18 END;
19 /
Iteration [1]
Iteration [2]
Iteration [3]
PL/SQL procedure successfully completed.
SQL>

</source>

==Empty Loop statement==



<source lang="sql">

SQL>
SQL> BEGIN
2 LOOP
3 NULL;
4 EXIT;
5 END LOOP;
6 END;
7 /
PL/SQL procedure successfully completed.
SQL>
SQL> --

</source>

==Insert a row into MyTable with the current value of the loop counter.==



<source lang="sql">

SQL>
SQL>
SQL> CREATE TABLE MyTable (
2 num_col NUMBER,
3 char_col VARCHAR2(60)
4 );
Table created.
SQL>
SQL> DECLARE
2 v_Counter BINARY_INTEGER := 1;
3 BEGIN
4 LOOP
5 INSERT INTO MyTable
6 VALUES (v_Counter, "Loop index");
7 v_Counter := v_Counter + 1;
8 IF v_Counter > 50 THEN
9 EXIT;
10 END IF;
11 END LOOP;
12 END;
13 /
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL> drop table MyTable;
Table dropped.
SQL>
SQL>

</source>

==LOOP..END LOOP, Cursor Loop==



<source lang="sql">

SQL>
SQL> CREATE TABLE lecturer (
2 id NUMBER(5) PRIMARY KEY,
3 first_name VARCHAR2(20),
4 last_name VARCHAR2(20),
5 major VARCHAR2(30),
6 current_credits NUMBER(3)
7 );
Table created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10001, "Scott", "Lawson","Computer Science", 11);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major, current_credits)
2 VALUES (10002, "Mar", "Wells","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10003, "Jone", "Bliss","Computer Science", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10004, "Man", "Kyte","Economics", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10005, "Pat", "Poll","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10006, "Tim", "Viper","History", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10007, "Barbara", "Blues","Economics", 7);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10008, "David", "Large","Music", 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10009, "Chris", "Elegant","Nutrition", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10010, "Rose", "Bond","Music", 7);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10011, "Rita", "Johnson","Nutrition", 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10012, "Sharon", "Clear","Computer Science", 3);
1 row created.
SQL>
SQL> CREATE TABLE myStudent (
2 student_id NUMBER(5) NOT NULL,
3 department CHAR(3) NOT NULL,
4 course NUMBER(3) NOT NULL,
5 grade CHAR(1)
6 );
Table created.
SQL>
SQL>
SQL>
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10000, "CS", 102, "A");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10002, "CS", 102, "B");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10003, "CS", 102, "C");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10000, "HIS", 101, "A");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10001, "HIS", 101, "B");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10002, "HIS", 101, "B");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10003, "HIS", 101, "A");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10004, "HIS", 101, "C");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10005, "HIS", 101, "C");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10006, "HIS", 101, "E");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10007, "HIS", 101, "B");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10008, "HIS", 101, "A");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10009, "HIS", 101, "D");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10010, "HIS", 101, "A");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10008, "NUT", 307, "A");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10010, "NUT", 307, "A");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10009, "MUS", 410, "B");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10006, "MUS", 410, "E");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10011, "MUS", 410, "B");
1 row created.
SQL>
SQL> INSERT INTO myStudent (student_id, department, course, grade)
2 VALUES (10000, "MUS", 410, "B");
1 row created.
SQL>
SQL>
SQL> CREATE TABLE MyTable (
2 num_col NUMBER,
3 char_col VARCHAR2(60)
4 );
Table created.
SQL>
SQL> DECLARE
2 myLecturerID lecturer.id%TYPE;
3 myFirstName lecturer.first_name%TYPE;
4 v_LastName lecturer.last_name%TYPE;
5
6 CURSOR myHistoryLecturer IS
7 SELECT id, first_name, last_name
8 FROM lecturer
9 WHERE major = "History";
10 BEGIN
11 OPEN myHistoryLecturer;
12 LOOP
13 FETCH myHistoryLecturer INTO myLecturerID, myFirstName, v_LastName;
14
15 EXIT WHEN myHistoryLecturer%NOTFOUND;
16
17 INSERT INTO myStudent (student_id, department, course)
18 VALUES (myLecturerID, "HIS", 301);
19
20 INSERT INTO MyTable (num_col, char_col)
21 VALUES (myLecturerID, myFirstName || " " || v_LastName);
22
23 END LOOP;
24
25 CLOSE myHistoryLecturer;
26
27 COMMIT;
28 END;
29 /
PL/SQL procedure successfully completed.
SQL>
SQL> select * from MyTable;
NUM_COL CHAR_COL
---------- ------------------------------------------------------------
10002 Mar Wells
10005 Pat Poll
10006 Tim Viper
SQL>
SQL> drop table MyTable;
Table dropped.
SQL>
SQL> drop table lecturer;
Table dropped.
SQL> drop table myStudent;
Table dropped.
SQL>
SQL>

</source>

==Loop with label==



<source lang="sql">

SQL>
SQL>
SQL> DECLARE
2 lv_counter_num PLS_INTEGER := 0;
3 BEGIN
4 <<LOOP1>>
5 LOOP
6 <<LOOP2>>
7 LOOP
8 lv_counter_num := lv_counter_num + 1;
9 DBMS_OUTPUT.PUT_LINE("Counter: " ||lv_counter_num);
10 EXIT LOOP1 WHEN lv_counter_num = 3;
11 END LOOP LOOP2;
12 DBMS_OUTPUT.PUT_LINE("Exited LOOP2");
13 END LOOP LOOP1;
14 DBMS_OUTPUT.PUT_LINE("Exited LOOP1");
15 END;
16 /
Counter: 1
Counter: 2
Counter: 3
Exited LOOP1
PL/SQL procedure successfully completed.
SQL>

</source>

==unconstrained loop==



<source lang="sql">

SQL>
SQL> declare
2 l_loops number := 0;
3 begin
4 dbms_output.put_line("Before my loop");
5
6 loop
7 if l_loops > 4 then
8 exit;
9 end if;
10 dbms_output.put_line("Looped " || l_loops || " times");
11 l_loops := l_loops + 1;
12 end loop;
13
14 dbms_output.put_line("After my loop");
15 end;
16 /
Before my loop
Looped 0 times
Looped 1 times
Looped 2 times
Looped 3 times
Looped 4 times
After my loop
PL/SQL procedure successfully completed.
SQL>

</source>

==Use EXIT WHEN to exit a loop==



<source lang="sql">

SQL>
SQL> DECLARE
2 v_Radius NUMBER := 2;
3 BEGIN
4 LOOP
5 DBMS_OUTPUT.PUT_LINE("The AREA of the circle is "
6 || v_RADIUS*v_RADIUS);
7 v_Radius := v_Radius + 2;
8 EXIT WHEN v_Radius > 10;
9 END LOOP;
10 END;
11 /
The AREA of the circle is 4
The AREA of the circle is 16
The AREA of the circle is 36
The AREA of the circle is 64
The AREA of the circle is 100
PL/SQL procedure successfully completed.
SQL> --

</source>

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Oracle PL/SQL/PL SQL/Loop - История изменений

в 13:45, 26 мая 2010

Admin: 1 версия