How to use update trigger in sql server 2008 with specific column

Question

Hello friends currently my trigger updates on table update, and I need to change this to only fire when specific column changes.
/****** Object: Table [dbo].[User_Detail] ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[User_Detail](
[sno] [int] IDENTITY(1,1) NOT NULL,
[userid] [nvarchar](50) NULL,
[name] [nvarchar](max) NULL,
[jointype] [nvarchar](50) NULL,
[joinside] [nvarchar](50) NULL,
[lleg] [nvarchar](50) NULL,
[rleg] [nvarchar](50) NULL,
[ljoining] [int] NULL,
[rjoining] [int] NULL,
[pair] [int] NULL
) ON [PRIMARY]
GO
/****** Object: Table [dbo].[User_Detail] table data ******/
SET IDENTITY_INSERT [dbo].[User_Detail] ON
INSERT [dbo].[User_Detail] values (1, N'LDS', N'LDS Rajput', N'free', N'Left', N'jyoti123', N'SUNIL', 6, 4, 4)
INSERT [dbo].[User_Detail] VALUES (2, N'jyoti123', N'jyoti rajput', N'free', N'Left', N'mhesh123', N'priya123', 3, 2, 2)
SET IDENTITY_INSERT [dbo].[User_Detail] OFF
/****** Object: Table [dbo].[User_Detail] trigger ******/
CREATE TRIGGER triggAfterUpdate ON User_Detail
FOR UPDATE
AS
declare @userid nvarchar(50);
declare @pair varchar(100);
select @userid=i.userid from inserted i;
select @pair=i.pair from inserted i;
SET NOCOUNT ON
if update(pair)
begin
insert into Complete_Pairs(userid,pair)
values(@userid,1);
end
GO
/****** Object: Table [dbo].[Complete_Pairs] Script Date: 05/22/2014 21:20:35 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Complete_Pairs](
[Sno] [int] IDENTITY(1,1) NOT NULL,
[userid] [nvarchar](50) NULL,
[pair] [int] NULL
) ON [PRIMARY]
GO
my query is TRIGGER triggAfterUpdate is fired only when pair column in User_Details table is update only and when we update other column like ljoin or rjoin then my trigger is not fired
please any one can suggest us how it can done or provide solution
Jitendra Kumar Sr. Software Developer at Ruvixo Technologies 7895253402

Answer 1

>select @userid=i.userid
frominserted i;
        select
@pair=i.pair
frominserted i;
The code above assumes a single row UPDATE.
You have to setup the trigger for set processing like when 100 rows are updated in a single statement.
UPDATE trigger example: http://www.sqlusa.com/bestpractices2005/timestamptrigger/
Kalman Toth Database & OLAP Architect
SQL Server 2014 Design & Programming
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