Question

我有以下查询：

SELECT        UsersAccountLink.UserId, Customer.Account.AccountNumber, Web.Customer.Name, Web.Customer.Street, UsersAccountLink.AccountId
FROM            UsersAccountLink INNER JOIN
                         Web.Customer ON UsersAccountLink.AccountId = Web.Customer.AccountId LEFT OUTER JOIN
                         Customer.Account ON UsersAccountLink.AccountId = Customer.Account.AccountId
WHERE        (Customer.Account.AccountNumber IS NULL)
Order by Name

我需要将选择更改为并更新。如果Customer.Account.AcountNumber为NULL，我需要将UsersAccountLink.UserId设置为空guid。

我怀疑我有这个权利，所以这就是我想出来的：

UPDATE
    UsersAccountLink
SET
    UsersAccountLink.AccountId = '00000000-0000-0000-0000-000000000000'
FROM            
    UsersAccountLink 
INNER JOIN
    Web.Customer ON UsersAccountLink.AccountId = Web.Customer.AccountId 
LEFT OUTER JOIN
    Customer.Account ON UsersAccountLink.AccountId = Customer.Account.AccountId
WHERE        
    (Customer.Account.AccountNumber IS NULL)

我的帖子基于How do I UPDATE from a SELECT in SQL Server?

UPDATE
    Table
SET
    Table.col1 = other_table.col1,
    Table.col2 = other_table.col2
FROM
    Table
INNER JOIN
    other_table
ON
    Table.id = other_table.id

两个问题：

有没有办法在实际运行之前测试运行查询，例如更新或删除？
我是否将其正确转换为更新？

谢谢！

Answer 1

This is what you can do to test

insert a select statment here to view the record(s) before the insert
BEgin tran
UPDATE
    UsersAccountLink
SET
    UsersAccountLink.AccountId = '00000000-0000-0000-0000-000000000000'
FROM            
    UsersAccountLink 
INNER JOIN
    Web.Customer ON UsersAccountLink.AccountId = Web.Customer.AccountId 
LEFT OUTER JOIN
    Customer.Account ON UsersAccountLink.AccountId = Customer.Account.AccountId
WHERE        
    (Customer.Account.AccountNumber IS NULL)

insert a select statment here to view the record(s) after the insert
Rollback tran

最好不要在开发时这样做。在您遇到的特定情况下，我还想测试如果稍后在不同记录上运行会发生什么。或者至少检查一下，确保你没有一个独特的指数。

我也喜欢这样做：

UPDATE
    UsersAccountLink
SET
    UsersAccountLink.AccountId = '00000000-0000-0000-0000-000000000000'
--SELECT * (or you can specify columns you specifically want to see)

FROM            
    UsersAccountLink 
INNER JOIN
    Web.Customer ON UsersAccountLink.AccountId = Web.Customer.AccountId 
LEFT OUTER JOIN
    Customer.Account ON UsersAccountLink.AccountId = Customer.Account.AccountId
WHERE        
    (Customer.Account.AccountNumber IS NULL)

这使您可以通过运行注释选择轻松检查。通过编写select，然后将更新信息放在其上并在FROM statmenet之前评论select中的所有内容，可以轻松地将select更改为更新。

将查询更改为更新

1 个答案: