我需要为每种类型的查询使用单独的索引，还是一个多列索引可以工作？

Question

WickedNet

Asked: 2018-05-05 06:25:26 +0800 CST2018-05-05 06:25:26 +0800 CST 2018-05-05 06:25:26 +0800 CST

UPDATE 结合嵌套的 SELECT 查询和 LEFT OUTER JOIN

772

我对包含嵌套 SELECT 语句和 LEFT OUTER JOIN 语句的 UPDATE 语句有疑问。

情况：在我们的数据库中，向我们数据库中的所有人添加了一个新列，我想在某些人上更新值为“X”的列，但仅限于具有某些条件的人。

通过以下 SELECT 语句，我成功选择了所有需要更新此列的人。我要更新的列是“Testfield”

SELECT
    TESTDB.CONTACT.number2 AS CustomerID,
    TESTDB.PERSON.firstname AS FirstName,
    TESTDB.PERSON.lastname AS LastName,
    (SELECT UPPER(string19) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) AS Testfield
FROM         
    TESTDB.CONTACT 
    LEFT OUTER JOIN TESTDB.PERSON ON TESTDB.CONTACT.contact_id = TESTDB.PERSON.contact_id
    LEFT OUTER JOIN TESTDB.UDPERSONSMALL ON TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.udpersonSmall_id 
    LEFT OUTER JOIN TESTDB.UDCONTACTLARGE ON TESTDB.CONTACT.userdef2_id = TESTDB.UDCONTACTLARGE.udcontactLarge_id
WHERE 
    (TESTDB.CONTACT.contact_id = TESTDB.PERSON.contact_id) 
/*  No retired people*/
    AND TESTDB.PERSON.retired = '0'
/*  Other conditions*/
    AND ((SELECT UPPER(string05) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'A'
    OR  (SELECT UPPER(string07) FROM CRM5.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'B'
    OR  (SELECT UPPER(string08) FROM CRM5.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'C')
/*  testpersonen*/
    AND (SELECT string45 FROM TESTDB.UDPERSONLARGE WHERE TESTDB.PERSON.userdef2_id = TESTDB.UDPERSONLARGE.UDPERSONLARGE_id) = '123'
ORDER BY
    CustomerID, FirstName, LastName

输出：

10001;Test1;Person1;
10001;Test2;Person2;
10001;Test3;Person3;
10001;Test4;Person4;
10001;Test6;Person6;
10001;Test7;Person7;
10001;Test8;Person8;

(7 rows affected)

这是正确的，人们目前在 Testfield 上的值为 NULL。（第四栏为空）

现在我想更新“Testfield”列，到目前为止尝试了这个：

UPDATE
    TESTDB.CONTACT 
    LEFT OUTER JOIN TESTDB.PERSON ON TESTDB.CONTACT.contact_id = TESTDB.PERSON.contact_id
    LEFT OUTER JOIN TESTDB.UDPERSONSMALL ON TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.udpersonSmall_id 
    LEFT OUTER JOIN TESTDB.UDCONTACTLARGE ON TESTDB.CONTACT.userdef2_id = TESTDB.UDCONTACTLARGE.udcontactLarge_id
SET
    (SELECT UPPER(string19) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'J'
WHERE 
    (TESTDB.CONTACT.contact_id = TESTDB.PERSON.contact_id) 
/*  No retired people*/
    AND TESTDB.PERSON.retired = '0'
/*  Other conditions*/
    AND ((SELECT UPPER(string05) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'A'
    OR  (SELECT UPPER(string07) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'B'
    OR  (SELECT UPPER(string08) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'C')
/*  testpersonen*/
    AND (SELECT string45 FROM TESTDB.UDPERSONLARGE WHERE TESTDB.PERSON.userdef2_id = TESTDB.UDPERSONLARGE.UDPERSONLARGE_id) = '123'

但是在这里我得到了它不接受放置在这里的 LEFT OUTER JOIN 的错误：

Msg 156, Level 15, State 1, Server TESTSERVER, Line 3
Incorrect syntax near the keyword 'LEFT'.
Msg 156, Level 15, State 1, Server TESTSERVER, Line 7
Incorrect syntax near the keyword 'SET'.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 7
Incorrect syntax near '='.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 15
Incorrect syntax near '='.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 16
Incorrect syntax near '='.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 17
Incorrect syntax near '='.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 19
Incorrect syntax near '='.

我也试过这样：

UPDATE
    TESTDB
SET
    (SELECT UPPER(string19) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'X'
FROM
    TESTDB.CONTACT 
    LEFT OUTER JOIN TESTDB.PERSON ON TESTDB.CONTACT.contact_id = TESTDB.PERSON.contact_id
    LEFT OUTER JOIN TESTDB.UDPERSONSMALL ON TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.udpersonSmall_id 
    LEFT OUTER JOIN TESTDB.UDCONTACTLARGE ON TESTDB.CONTACT.userdef2_id = TESTDB.UDCONTACTLARGE.udcontactLarge_id
WHERE 
    (TESTDB.CONTACT.contact_id = TESTDB.PERSON.contact_id) 
/*  No retired people*/
    AND TESTDB.PERSON.retired = '0'
/*  Other conditions*/
    AND ((SELECT UPPER(string05) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'X'
    OR  (SELECT UPPER(string07) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'X'
    OR  (SELECT UPPER(string08) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'X')
/*  testpersonen*/
    AND (SELECT string45 FROM TESTDB.UDPERSONLARGE WHERE TESTDB.PERSON.userdef2_id = TESTDB.UDPERSONLARGE.UDPERSONLARGE_id) = '123'

这导致另一个错误：

Msg 102, Level 15, State 1, Server TESTSERVER, Line 4
Incorrect syntax near '('.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 4
Incorrect syntax near '='.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 17
Incorrect syntax near '='.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 18
Incorrect syntax near '='.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 19
Incorrect syntax near '='.
Msg 102, Level 15, State 1, Server TESTSERVER, Line 21
Incorrect syntax near '='.

该软件是一个带有 SQL Server 2005 数据库的 CRM。

有人可以帮我语法吗？我要迷路了。

提前致谢。

2 个回答

Voted

Tara Kizer · Answer 1 · 2018-05-05T07:29:00+08:00

Best Answer

Tara Kizer

2018-05-05T07:29:00+08:002018-05-05T07:29:00+08:00

您的SELECT查询可以简化很多，这样可以更容易地确定需要什么 UPDATE 语句。所有这些SELECT UPPER都是不必要的，因为您已经加入了它们，所以只需参考该列。

在测试环境中试试这个：

UPDATE c
SET TestField = UPPER(udps.string19)
FROM         
    TESTDB.CONTACT c
    LEFT OUTER JOIN TESTDB.PERSON p ON c.contact_id = p.contact_id
    LEFT OUTER JOIN TESTDB.UDPERSONSMALL udps ON p.userdef_id = udps.udpersonSmall_id 
    LEFT OUTER JOIN TESTDB.UDCONTACTLARGE udc ON c.userdef2_id = udc.udcontactLarge_id
    LEFT OUTER JOIN TESTDB.UDPERSONLARGE udpl ON p.userdef2_id = udpl.UDPERSONLARGE_id
WHERE 
/*  No retired people*/
    p.retired = '0'
/*  Other conditions*/
    AND (UPPER(udps.string05) = 'A'
    OR   UPPER(udps.string07) = 'B'
    OR   UPPER(udps.string08) = 'C')
/*  testpersonen*/
    AND udpl.string45 = '123'

3

Shaulinator · Answer 2 · 2018-05-05T07:26:53+08:00

看看这是否有帮助：

Update TESTDB.CONTACT 
SET Testfield = SubTestField
FROM
(
SELECT
    TESTDB.CONTACT.number2 AS CustomerID,
    TESTDB.PERSON.firstname AS FirstName,
    TESTDB.PERSON.lastname AS LastName,
    TESTDB.CONTACT.contact_id AS SubContact_ID
    (SELECT UPPER(string19) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) AS SubTestfield
FROM         
    TESTDB.CONTACT 
    LEFT OUTER JOIN TESTDB.PERSON ON TESTDB.CONTACT.contact_id = TESTDB.PERSON.contact_id
    LEFT OUTER JOIN TESTDB.UDPERSONSMALL ON TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.udpersonSmall_id 
    LEFT OUTER JOIN TESTDB.UDCONTACTLARGE ON TESTDB.CONTACT.userdef2_id = TESTDB.UDCONTACTLARGE.udcontactLarge_id
WHERE 
    (TESTDB.CONTACT.contact_id = TESTDB.PERSON.contact_id) 
/*  No retired people*/
    AND TESTDB.PERSON.retired = '0'
/*  Other conditions*/
    AND (
    (SELECT UPPER(string05) FROM TESTDB.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'A'
    OR  (SELECT UPPER(string07) FROM CRM5.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'B'
    OR  (SELECT UPPER(string08) FROM CRM5.UDPERSONSMALL WHERE TESTDB.PERSON.userdef_id = TESTDB.UDPERSONSMALL.UDPERSONSMALL_id) = 'C'
    )
/*  testpersonen*/
    AND (SELECT string45 FROM TESTDB.UDPERSONLARGE WHERE TESTDB.PERSON.userdef2_id = TESTDB.UDPERSONLARGE.UDPERSONLARGE_id) = '123'
    )Sub
Where TESTDB.CONTACT.contact_id = SubContact_ID

您的 set 子句需要有一个值来比较。有关另一个示例，请参见Robin Day的此答案。我还将发布下面的示例以方便查看。

UPDATE
    Table_A
SET
    Table_A.col1 = Table_B.col1,
    Table_A.col2 = Table_B.col2
FROM
    Some_Table AS Table_A
    INNER JOIN Other_Table AS Table_B
        ON Table_A.id = Table_B.id
WHERE
    Table_A.col3 = 'cool'

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