多个内部加入 - SQL

Question

我有这样的SQL请求，但不工作...我真的不知道为什么，因为我与SQL开始...

Select CDR.*, 
    p1.*, 
    p2.*, 
    p3.* 
From dbo.T_CDR_APPEL CDR 
    Inner Join dbo.POS As p1 On CDR.CDR_LOC_CODE = p1.Loc_Code And 
    CDR.CDR_LOC_CODE Like 'SC%VI%' And CDR.CDR_TYPE Like 'I%' 
    Inner Join dbo.POS As p2 On CDR.CDR_LAST_REDIR_NO = p2.Post_type And 
    CDR.CDR_LOC_CODE Like 'CCN%' And CDR.CDR_TYPE Like 'I' 
    Inner Join dbo.POS As p3 On CDR.CDR_LAST_REDIR_NO = p3.Backup_Number And 
    CDR.CDR_LOC_CODE Like 'VoiceMail%' And CDR.CDR_TYPE Like 'IF' 

感谢您的帮助

Answer 1

你的SELECT语句

Select CDR.*, 
    p1.*, 
    p2.*, 
    p3.* 
From dbo.T_CDR_APPEL CDR 
    Inner Join dbo.POS As p1 On CDR.CDR_LOC_CODE = p1.Loc_Code And 
    CDR.CDR_LOC_CODE Like 'SC%VI%' And CDR.CDR_TYPE Like 'I%' 
    Inner Join dbo.POS As p2 On CDR.CDR_LAST_REDIR_NO = p2.Post_type And 
    CDR.CDR_LOC_CODE Like 'CCN%' And CDR.CDR_TYPE Like 'I' 
    Inner Join dbo.POS As p3 On CDR.CDR_LAST_REDIR_NO = p3.Backup_Number And 
    CDR.CDR_LOC_CODE Like 'VoiceMail%' And CDR.CDR_TYPE Like 'IF' 

是基本相同

SELECT CDR.*, 
    p1.*, 
    p2.*, 
    p3.* 
FROM dbo.T_CDR_APPEL CDR 
    INNER JOIN dbo.POS AS p1 ON CDR.CDR_LOC_CODE = p1.Loc_Code 
    INNER JOIN dbo.POS AS p2 ON CDR.CDR_LAST_REDIR_NO = p2.Post_type 
    INNER JOIN dbo.POS AS p3 ON CDR.CDR_LAST_REDIR_NO = p3.Backup_Number 
WHERE 
    CDR.CDR_LOC_CODE LIKE 'SC%VI%' AND  
    CDR.CDR_LOC_CODE LIKE 'CCN%' AND 
    CDR.CDR_LOC_CODE LIKE 'VoiceMail%' AND 
    CDR.CDR_TYPE LIKE 'I%' AND 
    CDR.CDR_TYPE LIKE 'I' AND 
    CDR.CDR_TYPE LIKE 'IF' 

因此，问题是WHERE子句与CDR.CDR_LOC_CODE和CDR.CDR_TYPE相同的列的AND条件的许多组合。请尝试用OR代替AND。

更新： 由于p1,p2,p3是相同的表，避免重复列，试试这个

SELECT CDR.*, p.* FROM 
(
    SELECT *, 
    (CASE 
     WHEN CDR_TYPE LIKE 'I%' THEN CDR_LOC_CODE 
     WHEN CDR_TYPE LIKE 'I' THEN CDR_LAST_REDIR_NO 
     WHEN CDR_TYPE LIKE 'IF' THEN CDR_LAST_REDIR_NO 
     ELSE '' 
    END) TMP_COL FROM dbo.T_CDR_APPEL 
) CDR 
INNER JOIN dbo.POS p ON 
    (CASE 
     WHEN CDR.CDR_TYPE LIKE 'I%' THEN p.Loc_Code 
     WHEN CDR.CDR_TYPE LIKE 'I' THEN p.Post_type 
     WHEN CDR.CDR_TYPE LIKE 'IF' THEN p.Backup_Number 
     ELSE '' 
    END) = CDR.TMP_COL 
WHERE 
    (CDR.CDR_LOC_CODE LIKE 'SC%VI%' AND CDR.CDR_TYPE LIKE 'I%') OR 
    (CDR.CDR_LOC_CODE LIKE 'CCN%' AND CDR.CDR_TYPE LIKE 'I') OR 
    (CDR.CDR_LOC_CODE LIKE 'VoiceMail%' AND CDR.CDR_TYPE LIKE 'IF') 

注：运行上述查询可能需要一段时间与大表。您可能需要为WHERE子句添加一些条件以进一步调整。我们还应该把WHERE子句放到子查询中，因为CDR_LOC_CODE和CDR_TYPE与dbo.T_CDR_APPEL是同一个表。另外，请检查动态列TMP_COL的空值或空值，以避免连接表ON '' = ''或ON NULL = NULL。

SELECT CDR.*, p.* FROM 
(
    SELECT *, 
    (CASE 
     WHEN CDR_TYPE LIKE 'I%' THEN CDR_LOC_CODE 
     WHEN CDR_TYPE LIKE 'I' THEN CDR_LAST_REDIR_NO 
     WHEN CDR_TYPE LIKE 'IF' THEN CDR_LAST_REDIR_NO 
     ELSE '' 
    END) TMP_COL FROM dbo.T_CDR_APPEL 
    WHERE 
     (CDR_LOC_CODE LIKE 'SC%VI%' AND CDR_TYPE LIKE 'I%') OR 
     (CDR_LOC_CODE LIKE 'CCN%' AND CDR_TYPE LIKE 'I') OR 
     (CDR_LOC_CODE LIKE 'VoiceMail%' AND CDR_TYPE LIKE 'IF') 
) CDR 
INNER JOIN dbo.POS p ON 
    (CASE 
     WHEN CDR.CDR_TYPE LIKE 'I%' THEN p.Loc_Code 
     WHEN CDR.CDR_TYPE LIKE 'I' THEN p.Post_type 
     WHEN CDR.CDR_TYPE LIKE 'IF' THEN p.Backup_Number 
     ELSE '' 
    END) = CDR.TMP_COL AND NULLIF(CDR.TMP_COL, '') IS NOT NULL