Question

因此，我一直在替换应用程序中的所有旧查询，以删除*=运算符。在其中一个查询中，我在弄清楚为什么输出不同时遇到了一些麻烦。

这是旧查询：

 SELECT 
    URMS_User_Name AS FE_Name,
    URMS_User_ID AS FE_Code, 
    COUNT( MRFS_FE_Code ) AS No_Of_Jobs, 
    SCRM_Service_Center_Name AS Service_Center_Name, 
    CSMSDVLP.fnGetExpertise( URMS_User_ID ) AS Expertise 
 FROM 
    TBL_User_Master, 
    TBL_Service_Center_Master, 
    TBL_User_Role, 
    TBL_MR_FE_Schedule 
 WHERE                
    USRL_Role_Code = 'FE' AND
    URMS_User_ID = USRL_User_ID AND      
    SCRM_Service_Center_ID = URMS_Service_Center_ID AND
    URMS_User_ID *= MRFS_FE_Code AND
    MRFS_Scheduled_Date >= '28-Oct-2014 00:00:00' AND 
    MRFS_Scheduled_Date <= '04-Nov-2014 00:00:00' 
 GROUP BY 
    SCRM_Service_Center_Name,
    URMS_User_Name,
    URMS_User_ID 
 ORDER BY 
    URMS_User_ID

这是更新的查询：

SELECT 
    URMS_User_Name AS FE_Name,
    URMS_User_ID AS FE_Code,
    COUNT( MRFS_FE_Code ) AS No_Of_Jobs,
    SCRM_Service_Center_Name AS Service_Center_Name, 
    CSMSDVLP.fnGetExpertise( URMS_User_ID ) AS Expertise 
FROM 
    TBL_User_Master 
    Left Join TBL_MR_FE_Schedule 
       ON URMS_User_ID = MRFS_FE_Code 
    Inner Join TBL_Service_Center_Master 
       ON SCRM_Service_Center_ID = URMS_Service_Center_ID 
    Inner Join TBL_User_Role 
       ON URMS_User_ID = USRL_User_ID 
WHERE 
    USRL_Role_Code = 'FE'
    AND MRFS_Scheduled_Date >= '28-Oct-2014 00:00:00' 
    AND MRFS_Scheduled_Date <= '04-Nov-2014 00:00:00' 
GROUP BY 
    SCRM_Service_Center_Name,
    URMS_User_Name, 
    URMS_User_ID 
ORDER BY 
    URMS_User_ID

旧查询完全返回数据，但新查询返回空行。我尝试用交叉连接和相同的问题替换所有连接。

虽然，奇怪的是如果我在没有日期条件的情况下运行查询，一切似乎都能正常工作。所以，现在，我很困惑我是否犯了错误，或者只是老操作员表现得很疯狂。

Answer 1

外连接表的条件属于ON子句。外连接记录的MRFS_Scheduled_Date为NULL，因此使用WHERE子句删除它们，从而将外连接转换为内连接。由于WHERE子句比以前更具限制性，这可能是没有得到任何结果的原因。

SELECT 
  URMS_User_Name AS FE_Name, 
  URMS_User_ID AS FE_Code, 
  COUNT( MRFS_FE_Code ) AS No_Of_Jobs, 
  SCRM_Service_Center_Name AS Service_Center_Name, 
  CSMSDVLP.fnGetExpertise( URMS_User_ID ) AS Expertise 
FROM TBL_User_Master 
LEFT JOIN TBL_MR_FE_Schedule ON URMS_User_ID = MRFS_FE_Code AND MRFS_Scheduled_Date >= '28-Oct-2014 00:00:00' AND MRFS_Scheduled_Date <= '04-Nov-2014 00:00:00' 
INNER JOIN TBL_Service_Center_Master ON SCRM_Service_Center_ID = URMS_Service_Center_ID 
INNER JOIN TBL_User_Role ON URMS_User_ID = USRL_User_ID 
WHERE USRL_Role_Code = 'FE'  
GROUP BY SCRM_Service_Center_Name, URMS_User_Name, URMS_User_ID 
ORDER BY URMS_User_ID;

更新的SQL查询不返回数据，即使使用交叉连接也是如此

1 个答案: