Question

这是我确切的SQL代码，但它非常慢，我知道它很糟糕......

还有另一种方法可以做到这一点但速度更快吗？

UPDATE Customer SET Title = "MR", SurName = "Test", FirstName ="Bob", HomePostCode ="SW18" WHERE CustomerID IN (SELECT CxID FROM Production WHERE policy_number = "001C5T" AND member_number = "100" AND family_group = "000001" AND CxID > 0)

由于

Answer 1

试试这个（未经测试的）

UPDATE Customer c
JOIN Production p ON p.CxID = c.CustomerID
SET c.Title = "MR",
    c.SurName = "Test",
    c.FirstName ="Bob",
    c.HomePostCode ="SW18"
WHERE p.policy_number = "001C5T"
    AND p.member_number = "100"
    AND p.family_group = "000001"
    AND p.CxID > 0

Answer 2

您可以在更新中加入表格，因此不会有子选择。

Answer 3

我想你想要这样的东西：

UPDATE customer 
SET Title = "MR", SurName = "Test", FirstName ="Bob", HomePostCode ="SW18" 
FROM customer    
inner join production on customer.customerID = production.cxid 
where policy_number = "001C5T" AND member_number = "100" AND family_group = "000001" AND CxID > 0

Answer 4

要扩展krakover的答案，您可以加入表格：

UPDATE Customer JOIN 
Production P ON (C.CustomerID = P.CxID) 
AND (P.policy_number = "001C5T") 
AND (P.member_number = "100") 
AND (P.family_group = "000001") 
AND (P.CxID > 0)  
SET C.Title = "MR", C.SurName = "Test", C.FirstName ="Bob", C.HomePostCode ="SW18"

注意，请仔细检查表别名，具体取决于你的shema。

Answer 5

没有JOIN的另一种方法：

INSERT INTO Customer (CustomerID, Title, SurName, FirstName, HomePostCode)
SELECT CxID, 'MR', 'Test', 'Bob', 'SW18'
FROM Production
WHERE policy_number = '001C5T' AND member_number = '100' AND family_group = '000001' AND CxID > 0
ON DUPLICATE KEY UPDATE Title = VALUES(Title), SurName = VALUES(SurName), FirstName = VALUES(FirstName), HomePostCode = VALUES(HomePostCode)

这将要求您拥有并选择至少一个唯一列。我认为CustomerID是。

加快/提高SQL效率

5 个答案: