Oracle: Howto use Cursors and Dynamic Cursors
2011-07-01 11:00
661 查看
1. Open cursor with a dynamic select statement
2. Opening multiple queries using the same cursor variable
[/code]
SQL> SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL, 2 ENAME VARCHAR2(10), 3 JOB VARCHAR2(9), 4 MGR NUMBER(4), 5 HIREDATE DATE, 6 SAL NUMBER(7, 2), 7 COMM NUMBER(7, 2), 8 DEPTNO NUMBER(2)); Table created. SQL> SQL> INSERT INTO EMP VALUES (7369, 'SMITH', 'CLERK', 7902, TO_DATE('17-DEC-1980', 'DD-MON-YYYY'), 800, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7499, 'ALLEN', 'SALESMAN', 7698, TO_DATE('20-FEB-1981', 'DD-MON-YYYY'), 1600, 300, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7521, 'WARD', 'SALESMAN', 7698, TO_DATE('22-FEB-1981', 'DD-MON-YYYY'), 1250, 500, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7566, 'JONES', 'MANAGER', 7839, TO_DATE('2-APR-1981', 'DD-MON-YYYY'), 2975, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7654, 'MARTIN', 'SALESMAN', 7698,TO_DATE('28-SEP-1981', 'DD-MON-YYYY'), 1250, 1400, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7698, 'BLAKE', 'MANAGER', 7839,TO_DATE('1-MAY-1981', 'DD-MON-YYYY'), 2850, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7782, 'CLARK', 'MANAGER', 7839,TO_DATE('9-JUN-1981', 'DD-MON-YYYY'), 2450, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7788, 'SCOTT', 'ANALYST', 7566,TO_DATE('09-DEC-1982', 'DD-MON-YYYY'), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7839, 'KING', 'PRESIDENT', NULL,TO_DATE('17-NOV-1981', 'DD-MON-YYYY'), 5000, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7844, 'TURNER', 'SALESMAN', 7698,TO_DATE('8-SEP-1981', 'DD-MON-YYYY'), 1500, 0, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7876, 'ADAMS', 'CLERK', 7788,TO_DATE('12-JAN-1983', 'DD-MON-YYYY'), 1100, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7900, 'JAMES', 'CLERK', 7698,TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 950, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7902, 'FORD', 'ANALYST', 7566,TO_DATE('3-DEC-1981', 'DD-MON-YYYY'), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7934, 'MILLER', 'CLERK', 7782,TO_DATE('23-JAN-1982', 'DD-MON-YYYY'), 1300, NULL, 10); 1 row created. SQL> SQL> SQL> CREATE OR REPLACE PROCEDURE showemps (where_in IN VARCHAR2 := NULL) 2 IS 3 TYPE cv_typ IS REF CURSOR; 4 cv cv_typ; 5 v_nm emp.ename%TYPE; 6 BEGIN 7 OPEN cv FOR 8 'SELECT ename FROM emp WHERE ' || NVL (where_in, '1=1'); 9 LOOP 10 FETCH cv INTO v_nm; 11 EXIT WHEN cv%NOTFOUND; 12 DBMS_OUTPUT.PUT_LINE (v_nm); 13 END LOOP; 14 CLOSE cv; 15 END; 16 / Procedure created. SQL> SQL> show error No errors. SQL> SQL> EXEC showemps(null); SMITH ALLEN WARD JONES MARTIN BLAKE CLARK SCOTT KING TURNER ADAMS JAMES FORD MILLER PL/SQL procedure successfully completed. SQL> SQL> SQL> drop table emp; Table dropped.
------------------------------------------------------------------------
2. Opening multiple queries using the same cursor variable
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> DECLARE 2 TYPE rc is REF CURSOR; 3 refCursorValue rc; 4 productRecord product%ROWTYPE; 5 v_product_description VARCHAR2(20); 6 v_company_short_name VARCHAR2(30); 7 BEGIN 8 OPEN refCursorValue FOR SELECT *from product; 9 10 LOOP 11 FETCH refCursorValue INTO productRecord; 12 EXIT WHEN refCursorValue%NOTFOUND; 13 dbms_output.put_line(to_char(productRecord.product_id)||' '|| 14 rpad(productRecord.product_description,20,' ')); 15 END LOOP; 16 17 OPEN refCursorValue FOR SELECT h.product_description,o.company_short_name 18 FROM company o,product h 19 WHERE o.product_id =h.product_id; 20 21 LOOP 22 FETCH refCursorValue INTO v_product_description,v_company_short_name; 23 EXIT WHEN refCursorValue%NOTFOUND; 24 dbms_output.put_line(rpad(v_product_description,20,' ')||' '||rpad(v_company_short_name,30,' ')); 25 END LOOP; 26 CLOSE refCursorValue; 27 END; 28 / 1 Java 2 Oracle 3 C# 4 Javascript 5 Python Java A Inc. Java B Inc. Java C Inc. Oracle D Inc. Oracle E Inc. Oracle F Inc. PL/SQL procedure successfully completed. SQL> SQL> SQL> drop table product; Table dropped. SQL> drop table company; Table dropped.
--------------------------------------------------------------------------------------
3.Dyamic cursors in PL/SQL
[code]create or replace package dynamic_cursor is
type t_crs is ref cursor;
procedure dyn_sel (
tab_name in varchar2,
field_name in varchar2,
val in varchar2,
crs in out t_crs);
procedure openCursor;
end dynamic_cursor;
/
create or replace package body dynamic_cursor as
procedure dyn_sel (
tab_name in varchar2,
field_name in varchar2,
val in varchar2,
crs in out t_crs)
is
stmt varchar2(100);
begin
stmt := 'select * from ' || tab_name || ' where ' || field_name || ' = :1 ';
open crs for stmt using val;
end dyn_sel;
procedure openCursor is
tc t_crs;
f1 varchar2(50);
f2 varchar2(50);
begin
dyn_sel('test_for_cursor','a','two',tc);
loop
fetch tc into f1,f2;
exit when tc%notfound;
dbms_output.put_line(f2);
end loop;
end openCursor;
end dynamic_cursor;
/
begin
dynamic_cursor.openCursor;
end;
/ |
相关文章推荐
- How to Enabling and Diabling VxDMP devices for use with Oracle ASM
- How to use script to get all oracle EBS Form name and corresponding fmb file name
- Know How And When To Use System.Message_Level To Control Messages In Oracle Forms
- How to use script to get all Oracle EBS Concurrent Program/Report name and corresponding execution f
- Howto Enable and Use A2DP Sink on Ubuntu Linux with Bluez
- Ubuntu 14.04安装PostgreSQL How To Install and Use PostgreSQL on Ubuntu 14.04
- How To Perform Oracle Solaris 11 System Backup And Recovery
- How to export Oracle Database and packages
- A summary: how to use bit manipulation to solve problems easily and efficiently
- How to create a DLL library in C and then use it with C#
- [MST] Create Dynamic Types and use Type Composition to Extract Common Functionality
- Larbin learning (1)——How to compile and use larbin
- iOS开发UI-Quartz2D what about Quartz2D ?and how to use it ?
- How to use udev for Oracle ASM in Oracle Linux 5
- When and how to use a ThreadLocal
- How To Use a DataReader Against an Oracle Stored Procedure in Visual C# .NET
- How To Use Dynamic Sql in Sql Server ?
- the command 'vim' and how to use it
- How to use Spring @Component, @Repository, @Service and @Controller Annotations?