Cursor expressions using multiple levels of nested cursors : Cursor function « Cursor « Oracle PL/SQL Tutorial






SQL>
SQL>
SQL> create table product(
  2     product_id number(4)     not null,
  3     product_description varchar2(20) not null
  4  );

Table created.

SQL>
SQL> insert into product values (1,'Java');

1 row created.

SQL> insert into product values (2,'Oracle');

1 row created.

SQL> insert into product values (3,'C#');

1 row created.

SQL> insert into product values (4,'Javascript');

1 row created.

SQL> insert into product values (5,'Python');

1 row created.

SQL>
SQL>
SQL> create table company(
  2     product_id        number(4)    not null,
  3     company_id          NUMBER(8)    not null,
  4     company_short_name  varchar2(30) not null,
  5     company_long_name   varchar2(60)
  6  );

Table created.

SQL> insert into company values(1,1001,'A Inc.','Long Name A Inc.');

1 row created.

SQL> insert into company values(1,1002,'B Inc.','Long Name B Inc.');

1 row created.

SQL> insert into company values(1,1003,'C Inc.','Long Name C Inc.');

1 row created.

SQL> insert into company values(2,1004,'D Inc.','Long Name D Inc.');

1 row created.

SQL> insert into company values(2,1005,'E Inc.','Long Name E Inc.');

1 row created.

SQL> insert into company values(2,1006,'F Inc.','Long Name F Inc.');

1 row created.

SQL>
SQL>
SQL>
SQL> create table company_site(
  2     site_no number(4)       not null,
  3     site_descr varchar2(20) not null
  4  );

Table created.

SQL> insert into company_site values (1,'New York');

1 row created.

SQL> insert into company_site values (2,'Washington');

1 row created.

SQL> insert into company_site values (3,'Chicago');

1 row created.

SQL> insert into company_site values (4,'Dallas');

1 row created.

SQL> insert into company_site values (5,'San Francisco');

1 row created.

SQL>
SQL>
SQL> create table org_company_site(
  2     company_id number(8) not null,
  3     site_no number(4) not null
  4  );

Table created.

SQL> insert into org_company_site values (1001,1);

1 row created.

SQL> insert into org_company_site values (1002,2);

1 row created.

SQL> insert into org_company_site values (1003,3);

1 row created.

SQL> insert into org_company_site values (1004,1);

1 row created.

SQL> insert into org_company_site values (1004,2);

1 row created.

SQL> insert into org_company_site values (1004,3);

1 row created.

SQL> insert into org_company_site values (1005,1);

1 row created.

SQL> insert into org_company_site values (1005,4);

1 row created.

SQL> insert into org_company_site values (1005,5);

1 row created.

SQL> insert into org_company_site values (1006,1);

1 row created.

SQL>
SQL> create or replace function f_cursor_exp_complex return NUMBER
  2  is
  3    TYPE rc is REF CURSOR;
  4
  5    CURSOR myCursor IS
  6      SELECT h.product_description,
  7        CURSOR(SELECT o.company_long_name,
  8          CURSOR (SELECT s.site_descr
  9                  FROM org_company_site os,company_site s
 10                  WHERE os.site_no =s.site_no
 11                  AND os.company_id =o.company_id)as site_name
 12               FROM company o
 13               WHERE o.product_id =h.product_id)long_name
 14      FROM product h;
 15
 16    myRecord rc;
 17    company_rec rc;
 18    v_product_description VARCHAR2(20);
 19    v_company_long_name VARCHAR2(60);
 20    v_site_name VARCHAR2(20);
 21  BEGIN
 22
 23    OPEN myCursor;
 24    LOOP
 25
 26      FETCH myCursor INTO v_product_description,myRecord;
 27      EXIT WHEN myCursor%notfound;
 28      LOOP
 29
 30        FETCH myRecord INTO v_company_long_name,company_rec;
 31        EXIT WHEN myRecord%notfound;
 32        LOOP
 33          FETCH company_rec INTO v_site_name;
 34          EXIT WHEN company_rec%notfound;
 35          DBMS_OUTPUT.PUT_LINE(v_product_description ||''||v_company_long_name||''||v_site_name);
 36        END LOOP;
 37      END LOOP;
 38    END LOOP;
 39
 40    close myCursor;
 41    RETURN (0);
 42  EXCEPTION WHEN OTHERS THEN
 43    RETURN (SQLCODE);
 44  END;
 45  /

Function created.

SQL>
SQL> drop table company;

Table dropped.

SQL>
SQL> drop table product;

Table dropped.

SQL>
SQL> drop table company_site;

Table dropped.

SQL>
SQL> drop table org_company_site;

Table dropped.

SQL>








25.16.Cursor function
25.16.1.Cursor function
25.16.2.A PL/SQL function that uses a cursor expression
25.16.3.Cursor expressions using multiple levels of nested cursors
25.16.4.SYS_REFCURSOR as parameter
25.16.5.Passing data from one table function to another in a pipelined fashion