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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;

    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

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  • 原文地址:https://www.cnblogs.com/benbenduo/p/3978926.html
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