使用另一个表中的信息更新表中的列

Posted 2023-05-08

【中文标题】使用另一个表中的信息更新表中的列

【英文标题】：Update a column in table with information from another table

【发布时间】：2013-09-27 09:08:26

【问题描述】：

我已经有了这个：

USE [AdventureWorks2012];
--- somewhere create table  
IF OBJECT_ID('[dbo].[PersonPhone]','U') IS NOT NULL   
DROP TABLE [dbo].[PersonPhone]  
CREATE TABLE [dbo].[PersonPhone](  
    [BusinessEntityID] [int] NOT NULL,  
    [PhoneNumber] nvarchar(25) NOT NULL,  
    [PhoneNumberTypeID] [int] NOT NULL,  
    [ModifiedDate] [datetime] NOT NULL)  
--- and append new column  
ALTER Table [dbo].[PersonPhone]  
ADD [StartDate] date NULL  
--- after this, i want copy dates in this column (at another table, we increase dates by one)  
UPDATE [dbo].[PersonPhone]
SET [StartDate] = [NewTable].[NewDate]
FROM (
       SELECT DATEADD(day, 1, [HumanResources].[EmployeeDepartmentHistory].[StartDate]) AS [NewDate],
          row_number() over(order by (select 1)) AS [RN]
   FROM [HumanResources].[EmployeeDepartmentHistory]
 ) [NewTable]

如何改进查询以将值从 [NewTable] 复制到 [dbo].[PersonPhone].[StartDate] 行？

【参考方案1】：

在您更新时：

UPDATE [dbo].[PersonPhone]
SET [StartDate] = DATEADD(day, 1, [HumanResources].[EmployeeDepartmentHistory].[StartDate])
FROM [HumanResources].[EmployeeDepartmentHistory]
GO

SELECT row_number() over(order by (select 1)) AS [RN] FROM [HumanResources].[EmployeeDepartmentHistory]

【讨论】：

SQL Server 告诉我“此查询返回的结果不止一个...”

现在写，“不能为日期时间调用方法”

已复制，但所有行都有一个值。如何逐行复制？

如果是这样，如果我是你，我会将更新查询放入循环语句中。