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DB2存储过程语法规则
如何声明一个存储过程
CREATE PROCEDURE 存储过程名(IN 输入变量名 输入变量类型,OUT 输出变量名 输出变量类型)
紧跟其后的是存储过程属性列表
常用的有：LANGUAGE SQL、MODIFIES SQL DATA、RESULT SETS 1(返回结果集个数)
l 存储过程体以begin开始
l 存储过程体以end结束
存储过程约束规则
存储过程中调用存储过程
CALL 存储过程名（参数1，参数2，参数n）
例：
call spco_init_custom(bankcode,errno,errmsg);
GET DIAGNOSTICS retval=RETURN_STATUS;
if(retval<>0) then
set errno=errno;
set errmsg=errmsg;
return errno;
end if;
变量的定义
变量使用前必须先定义，方法为
DECLARE 变量名 变量类型 （default 默认值）
例：
DECLARE SQLCODE INTEGER DEFAULT 0;
DECLARE inum INTEGER DEFAULT 0;
DECLARE curtime char(8);
DECLARE bcode char(6);
DECLARE sqlstate char(5);
if 表达式
if 条件1 then
逻辑体；
elseif 条件2 then
逻辑体；
else
逻辑体；
end if;
例：
IF rating = 1 THEN
UPDATE employee
SET salary = salary * 1.10, bonus = 1000
WHERE empno = employee_number;
ELSEIF rating = 2 THEN
UPDATE employee
SET salary = salary * 1.05, bonus = 500
WHERE empno = employee_number;
ELSE
UPDATE employee
SET salary = salary * 1.03, bonus = 0
WHERE empno = employee_number;
END IF;
case表达式
case 变量名 when
变量值1 then
. . .
when
变量值2 then
- - -
else
. . .
end case;
或
case when
变量名=变量值1 then
. . .
when
变量名=变量值2 then
- - -
else
. . .
end case;
例一：
CASE v_workdept
WHEN ‘A00‘
THEN UPDATE department
SET deptname = ‘DATA ACCESS 1‘;
WHEN ‘B01‘
THEN UPDATE department
SET deptname = ‘DATA ACCESS 2‘;
ELSE UPDATE department
SET deptname = ‘DATA ACCESS 3‘;
END CASE；
例二：
CASE
WHEN v_workdept = ‘A00‘
THEN UPDATE department
SET deptname = ‘DATA ACCESS 1‘;
WHEN v_workdept = ‘B01‘
THEN UPDATE department
SET deptname = ‘DATA ACCESS 2‘;
ELSE UPDATE department
SET deptname = ‘DATA ACCESS 3‘;
END CASE；
for 表达式
for 循环名 as
游标名或select 表达式
do
sql表达式；
end for;
例：
1）
DECLARE fullname CHAR(40);
FOR vl AS
SELECT firstnme, midinit, lastname FROM employee
DO
SET fullname = lastname || ‘,‘ || firstnme ||‘ ‘ || midinit;
INSERT INTO tnames VALUE (fullname);
END FOR
2）
for loopcs1 as cousor1 cursor as
select market_code as market_code
from tb_market_code
for update
do
end for;
goto表达式
goto 标示名；
标示名：
逻辑体；
例：
GOTO FAIL；
...
SUCCESS: RETURN 0
FAIL: RETURN -200
while表达式
while 条件表达式 do
逻辑体；
end while；
LOOP表达式
LOOP... END LOOP；
例：
OPEN c1;
ins_loop:
LOOP
FETCH c1 INTO v_dept, v_deptname, v_admdept;
IF at_end = 1 THEN
LEAVEins_loop; --中断循环
ELSEIF v_dept = ‘D11‘ THEN
ITERATEins_loop; --下一个循环
END IF;
INSERT INTO department (deptno, deptname, admrdept)
VALUES (‘NEW‘, v_deptname, v_admdept);
END LOOP;
CLOSE c1;
关于游标
定义游标：
DECLARE 游标名 CURSOR FOR
Select 语句；
打开游标：
OPEN 游标名；
取值：
FETCH 游标名 INTO 变量列表
例：
DECLARE c1 CURSOR FOR
SELECT CAST(salary AS DOUBLE)
FROM staff
WHERE DEPT = deptNumber
ORDER BY salary;
DECLARE EXIT HANDLER FOR NOT FOUND
SET medianSalary = 6666;
SET medianSalary = 0;
SELECT COUNT(*) INTO v_numRecords
FROM staff
WHERE DEPT = deptNumber;
OPEN c1;
WHILE v_counter < (v_numRecords / 2 + 1) DO
FETCH c1 INTO medianSalary;
SET v_counter = v_counter + 1;
END WHILE;
CLOSE c1;
注：游标的申明如果放在中间段，要用”begin。。。end;”.段分割标志分割开；
动态sql
1) declare stmt varchar(1024);
set stmt=‘create table zhouhaiming( f1 smallint, f2 varchar(9), f3 char(5) )‘;
prepare s1 from stmt;
execute s1;
set stmt=‘insert into zhouhaiming values (1,‘www‘,‘aaa‘)‘;
prepare s1 from stmt;
execute s1;
2) DECLARE CURSOR C1 FOR STMT1;
PREPARE STMT1 FROM
‘ALLOCATE C2 CURSOR FOR RESULT SET ?‘;
临时表的建立
DECLARE GLOBAL TEMPORARY TABLE TABLE_NAME
AS (FULLSELECT) DEFINITION ONLY
EXCLUDING IDENTITY COLUMN ATTRIBUTES
ON COMMIT DELETE ROWS
NOT LOGGED IN 临时表空间名with replace；
第一行規定臨時表的名稱.
第二行規定臨時表的列的定義.
第三行規定不是從源結果表定義中復制的恒等列.
第四行規定如果沒有打開WITH GOLD光標,將會刪除表的所有行.
第五行規定不對表的改變進行記錄.
With replace选项会隐式的自动删除该临时表。
例如:
DECLARE GLOBAL TEMPORARY TABLE DEC_BSEMPMS
AS (SELECT * FROM BSEMPMS) DEFINITION ONLY
EXCLUDING IDENTITY COLUMN ATTRIBUTES
ON COMMIT DELETE ROWS
NOT LOGGED；
DB2中的几个全局变量
n ROW_COUNT—影响行数
UPDATE CORPDATA.PROJECT
SET PRSTAFF = PRSTAFF + 1.5
WHERE DEPTNO = deptnbr;
GET DIAGNOSTICSrcount = ROW_COUNT;
n RETURN_STATUS--返回状态
CALL TRYIT;--调用存储过程
GET DIAGNOSTICSRETVAL = RETURN_STATUS;
IF RETVAL <> 0 THEN
...
LEAVE A1;
ELSE
...
END IF;
n SQLSTATE—SQL返回错误代码
注：使用前必先定义
declare sqlstate char(5);
declare state char(5);
insert into tbname values(…)
set state=sqlstate;
if(state<> ‘00000‘) then
return -1;
end if;
关于ATOMIC和NOT ATOMIC
P1:BEGIN ATOMIC –P1段的事务会自动回滚
P1:BEGIN NOT ATOMIC –P1段的事务不会自动回滚
DB2中的条件句柄
句柄类型:
n CONTINUE
n EXIT
n UNDO
条件类型：
n SQLSTATE string
n SQLEXCEPTION
n SQLWARNING
n NOT FOUND
例：
1）DECLARE EXIT HANDLER FOR NOT FOUND
SET medianSalary = 6666;
2） DECLARE not_found CONDITION FOR SQLSTATE ‘02000‘;
DECLARE EXIT HANDLER FOR not_found
SET rating = -1;
3) DECLARE not_found CONDITION FOR SQLSTATE ‘02000‘;
DECLARE c1 CURSOR FOR
SELECT deptno, deptname, admrdept
FROM department
ORDER BY deptno;
DECLARE CONTINUE HANDLER FOR not_found
SET at_end = 1;
如何抽取/提交存储过程
db2 "get routine into 文件名 from procedure 存储过程名"
抽取存储过程；
提交存储过程
db2 "put routine from 文件名"
安装已编译好的存储过程。
如何在命令符下提交存储过程
在存储过程的最后加上@符号，然后在命令符下打入：db2 -td@ -vf procfile.sql 就可以生成过程。
非存储过程的SQL文件，在命令符下打入：db2 –tvf sqlfile.sql
从存储过程返回结果集(游标)的用法
1、建一sp返回结果集
CREATE PROCEDURE DB2INST1.Proc1 (
LANGUAGE SQL
result sets 2 --(返回两个结果集)
P1: BEGIN
declare c1 cursor with return to caller for
select market_code
from tb_market_code;
--指定该结果集用于返回给调用者
declare c2 cursor with return to caller for
select market_code
from tb_market_code;
open c1;
open c2;
END P1
2、建一SP调该sp且使用它的结果集
CREATE PROCEDURE DB2INST1.Proc2 (
out out_market_code char(1))
LANGUAGE SQL
P1: BEGIN
declare loc1,loc2 result_set_locator varying;
--建立一个结果集数组
call proc1;
--调用该SP返回结果集。
associate result set locator(loc1,loc2) with procedure proc1;
--将返回结果集和结果集数组关联
allocate cursor1 cursor for result set loc1;
allocate cursor2 cursor for result set loc2;
--将结果集数组分配给cursor
fetch cursor1 into out_market_code;
--直接从结果集中赋值
close cursor1;
END P1
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/aawanghuan/archive/2008/02/20/2108951.aspx
DB2存储过程语法规则