db2存储过程小结

1.distinct 去掉重复的值，保证值唯一

2. 临时表字段默认字体颜色  if_check_cn     VARCHAR(500)  DEFAULT '<font color="blue">可以替换</font>'  --字体颜色为蓝色      

3.如果a表中phone_number为空，则取b表的 phone_number；用coalesce()函数

   coalesce(nullif(a.phone_number,''),b.phone_number)

4.向临时表插入数据

  insert into session.result(临时表字段 )

  select .(字段)...from .(表a)..left join .(表b)..on(a.字段=b.字段)(也可添加条件 and a.字段=xx) left join ..(可join 多个表) 

  where （条件） and ，order by xx;

5.向临时表中merge数据

(1)　　merge into session.result a
　　　　using(select  code from  c_wx where..)b
　　　　on a.code=b.code
　　　　when matched then update 

              set  a.price=1, a.price_cn='是',

              a.check_cn ='<font color="red" title="点击查看驳回意见" class="more-info" onclick="showCheckMsg('''||trim(char(cust_code))||''','||trim(char(a.if_check))||')">驳                   回&rsaquo;&rsaquo;</font>';

6.存储过程输出参数在java Action类中使用

简写一个存储过程

DROP PROCEDURE GetInfo
@
CREATE PROCEDURE GetInfo
(
    IN  p_code                 INT,
    OUT p_rejectInfo         VARCHAR(100)
    )
    LANGUAGE SQL
    DYNAMIC RESULT SETS 0
    
BEGIN

    DECLARE SQLCODE INT;
    DECLARE SQLSTATE CHAR(5);
    DECLARE v_errCode INT DEFAULT 0;
    DECLARE v_errState CHAR(5) DEFAULT '00000';    
    DECLARE v_save_state INT DEFAULT 0;    
    DECLARE v_rejectComm VARCHAR(100);  

    --------------------------------------------------------
    -- DECLARE ERROR HANDLERS
    --------------------------------------------------------
    
    DECLARE CONTINUE HANDLER FOR SQLEXCEPTION
    BEGIN
        SET v_errCode = SQLCODE;
        SET v_errState = SQLSTATE;
    END;
 
 
    SELECT reject_comm INTO v_rejectComm
    FROM g_info b
    LEFT JOIN DATA_LOG a
    ON a.check_person_id = b.person_id
    WHERE a.code=p_code;
        
    SET p_rejectInfo = v_rejectComm;    
    IF v_errCode <> 0 AND v_errCode <> 100 
    THEN 
        SET v_save_state = 1;
        GOTO QuitProc;
    END IF;     
    GOTO EndProc;
    
QuitProc:
    ROLLBACK;
    
EndProc:
    RETURN v_errCode;
END
@

在 action中获取值

public ActionForward checkMsgShow(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response) throws Exception {
        CallHelper helper = new CallHelper("GetInfo");
        helper.setParam("code",  request.getParameter("code"));
        helper.execute();        
        request.setAttribute("rejectInfo", (String) helper.getOutput("rejectInfo"));
        return mapping.findForward("checkMsgShow");
    }