SQL MERGE for Upsert example

gistfile1.txt

--- CREATE THE TABLE

USE [Bench]
GO

/****** Object:  Table [dbo].[users]    Script Date: 1/30/2014 5:42:46 PM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE [dbo].[users](
	[id] [int] IDENTITY(1,1) NOT NULL,
	[first_name] [nvarchar](50) NOT NULL,
	[last_name] [nvarchar](50) NOT NULL,
	[nickname] [nvarchar](50) NULL,
	[created_at] [datetime] NOT NULL,
	[updated_at] [datetime] NOT NULL,
 CONSTRAINT [PK_users] PRIMARY KEY CLUSTERED 
(
	[id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO


--- INSERT A RECORD
INSERT INTO users (first_name, last_name, nickname, created_at, updated_at)
VALUES ('John', 'Doe', 'Johnny', getdate(), getdate())
GO

--- UPSERT THE RECORD

MERGE
	users as target  --Table name
USING (
	VALUES (1, 'Joe', 'Doe', null, getdate(), getdate())
) as source (id, first_name, last_name, nickname, created_at, updated_at)

ON target.id = source.id

WHEN MATCHED THEN
	UPDATE SET
		first_name = source.first_name,
		last_name = source.last_name,
		nickname = source.nickname,
		created_at = source.created_at,
		updated_at = source.updated_at
WHEN NOT MATCHED THEN
	INSERT (first_name, last_name, nickname, created_at, updated_at)
	VALUES (source.first_name, source.last_name, source.nickname, source.created_at, source.updated_at)
;  -- semicolon important for merge

--- UPSERT A NEW RECORD
MERGE
	users as target  --Table name
USING (
	VALUES (2, 'Jane', 'Doe', null, getdate(), getdate())
) as source (id, first_name, last_name, nickname, created_at, updated_at)

ON target.id = source.id

WHEN MATCHED THEN
	UPDATE SET
		first_name = source.first_name,
		last_name = source.last_name,
		nickname = source.nickname,
		created_at = source.created_at,
		updated_at = source.updated_at
WHEN NOT MATCHED THEN
	INSERT (first_name, last_name, nickname, created_at, updated_at)
	VALUES (source.first_name, source.last_name, source.nickname, source.created_at, source.updated_at)
;

SELECT * FROM users  -- should be two records