Mega Code Archive
Nested cursor
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SQL>
SQL> CREATE TABLE emp (
2 id NUMBER PRIMARY KEY,
3 fname VARCHAR2(50),
4 lname VARCHAR2(50)
5 );
Table created.
SQL>
SQL> INSERT INTO emp (id, fname, lname)VALUES (1, 'A', 'B');
1 row created.
SQL> INSERT INTO emp (id, fname, lname)VALUES (2, 'C', 'D');
1 row created.
SQL> INSERT INTO emp (id, fname, lname)VALUES (3, 'Enn', 'F');
1 row created.
SQL> INSERT INTO emp (id, fname, lname)VALUES (4, 'G', 'H');
1 row created.
SQL> INSERT INTO emp (id, fname, lname)VALUES (5, 'G', 'Z');
1 row created.
SQL>
SQL> CREATE TABLE books (
2 isbn CHAR(10) PRIMARY KEY,
3 category VARCHAR2(20),
4 title VARCHAR2(100),
5 num_pages NUMBER,
6 price NUMBER,
7 copyright NUMBER(4),
8 emp1 NUMBER,
9 emp2 NUMBER,
10 emp3 NUMBER
11 );
Table created.
SQL>
SQL> INSERT INTO books (isbn, category, title, num_pages, price, copyright, emp1, emp2, emp3)
2 VALUES ('1', 'Database', 'Oracle', 563, 39.99, 2009, 1, 2, 3);
1 row created.
SQL> INSERT INTO books (isbn, category, title, num_pages, price, copyright, emp1, emp2)
2 VALUES ('2', 'Database', 'MySQL', 765, 44.99, 2009, 4, 5);
1 row created.
SQL> INSERT INTO books (isbn, category, title, num_pages, price, copyright, emp1, emp2, emp3)
2 VALUES ('3', 'Database', 'SQL Server', 404, 39.99, 2001, 6, 7, 8);
1 row created.
SQL>
SQL> SET SERVEROUTPUT ON ESCAPE OFF
SQL>
SQL> DECLARE
2
3 cv_emp SYS_REFCURSOR;
4 v_title BOOKS.TITLE%TYPE;
5 v_emp emp%ROWTYPE;
6 v_counter PLS_INTEGER := 0;
7
8 CURSOR book_cur IS SELECT b.title,CURSOR (SELECT * FROM emp a WHERE a.id = b.emp1 OR a.id = b.emp2 OR a.id = b.emp3)
9 FROM books b
10 WHERE isbn = '1';
11
12 BEGIN
13
14 DBMS_OUTPUT.ENABLE(1000000);
15
16 OPEN book_cur;
17
18 LOOP
19 FETCH book_cur INTO v_title, cv_emp;
20 EXIT WHEN book_cur%NOTFOUND;
21
22 v_counter := 0;
23
24 DBMS_OUTPUT.PUT_LINE('Title from the main cursor: '||v_title);
25
26 LOOP
27 FETCH cv_emp INTO v_emp;
28 EXIT WHEN cv_emp%NOTFOUND;
29
30 v_counter := v_counter + 1;
31
32 DBMS_OUTPUT.PUT_LINE('emp'||v_counter||': '||v_emp.fname||' '||v_emp.lname);
33 END LOOP;
34 END LOOP;
35
36 CLOSE book_cur;
37
38 END;
39 /
Title from the main cursor: Oracle
emp1: Enn F
emp2: C D
emp3: A B
PL/SQL procedure successfully completed.
SQL> drop table emp;
Table dropped.
SQL> drop table books;
Table dropped.
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