How to UPDATE from SELECT in SQL Server

In this article we will show you, How to write a SQL Query to UPDATE columns in a table using the SELECT Statement in SQL Server with example. This is one of the SQL Server Frequently Asked Question. For this example, We are going to use the below shown data

Below table will show the data present in Employee Duplicate table. Our task is to update the columns (firstname, lastname, and Yearly Income) in this table with the above specified table.

How to UPDATE from SELECT in SQL Server Example 1

In this example we will show you, How to update from select statement using the Subquery.

-- Query to UPDATE from SELECT in SQL Server
USE [SQL Tutorial]
GO

UPDATE [EmployeeDuplicates]
   SET [YearlyIncome] = ( SELECT [YearlyIncome] 
			  FROM [Employee]
			  WHERE [Employee].EmpID = [EmployeeDuplicates].EmpID)
 
GO

OUTPUT

Now let me show you the Updated table

How to UPDATE from SELECT in SQL Server Example 2

Above specified example might be a good option to update single column. In this example we will show you, How can I do an UPDATE statement with JOIN in SQL Server.

-- Query to UPDATE from SELECT in SQL Server
USE [SQL Tutorial]
GO

UPDATE [EmpDup]
   SET [EmpDup].[FirstName] = [Emp].[FirstName],
	   [EmpDup].[LastName] = [Emp].[LastName],
	   [EmpDup].[YearlyIncome] = [Emp].[YearlyIncome]
FROM [EmployeeDuplicates] AS [EmpDup]
INNER JOIN [Employee] AS [Emp] 
   ON [EmpDup].EmpID = [Emp].EmpID 
WHERE [EmpDup].EmpID = [Emp].EmpID 
GO

OUTPUT

Now let me show you the Updated table

How to UPDATE from SELECT in SQL Server Example 3

In this example we will show you, How to update the table columns using the Select statement. Here, we are using the Subquery at FROM statement

-- Query to UPDATE from SELECT in SQL Server
USE [SQL Tutorial]
GO

UPDATE [EmployeeDuplicates]
   SET [FirstName] = [Emp].[FirstName],
	   [LastName] = [Emp].[LastName],
	   [YearlyIncome] = [Emp].[YearlyIncome]
FROM (SELECT EmpID,
	     [FirstName], 
	     [LastName],
	     [YearlyIncome] 
       FROM [Employee]
     ) [Emp] 
WHERE [EmployeeDuplicates].EmpID = [Emp].EmpID 
GO

OUTPUT

Now let me show you the Updated table

How to UPDATE from SELECT in SQL Server Example 4

In this example we will show you, How to update the table columns from the Select statement using the MERGE Statement

-- Query to UPDATE from SELECT Statement in SQL Server
USE [SQL Tutorial]
GO

MERGE INTO [EmployeeDuplicates] AS [EmpDup]
   USING (
           SELECT EmpID,
		  [FirstName], 
		  [LastName],
		  [YearlyIncome] 
           FROM [Employee] 
         ) [Emp]
   ON [EmpDup].EmpID = [Emp].EmpID
WHEN MATCHED THEN
   UPDATE 
  	SET [EmpDup].[FirstName] = [Emp].[FirstName],
	    [EmpDup].[LastName] = [Emp].[LastName],
	    [EmpDup].[YearlyIncome] = [Emp].[YearlyIncome];

OUTPUT

Now let me show you the Updated table

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