Creating a single trigger for Insert/Update - sql-server

Question

I am using SQL Server 2008.
Assuming I have Table A which is a transaction table. And Table B which is a history table.
Whenever a row is inserted or updated in Table A, a new row should be inserted in Table B.
The Status column of Table B should change to INSERTED or UPDATED respectively.
How to handle this from a single trigger?

Answer 1

What you're asking for is quite simple:
CREATE TRIGGER TR_TableA_IU ON dbo.TableA FOR INSERT, UPDATE
AS
SET NOCOUNT ON;
INSERT dbo.TableB (Column1, Column2, Status)
SELECT
I.Column1,
I.Column2,
CASE WHEN EXISTS (SELECT * FROM Deleted) THEN 'UPDATED' ELSE 'INSERTED' END
FROM Inserted I;
If you also wanted to handle deletions, that can be done in a single statement, too:
CREATE TRIGGER TR_TableA_IUD ON dbo.TableA FOR INSERT, UPDATE, DELETE
AS
SET NOCOUNT ON;
INSERT dbo.TableB (Column1, Column2, Status)
SELECT
I.Column1,
I.Column2,
CASE WHEN EXISTS (SELECT * FROM Deleted) THEN 'UPDATED' ELSE 'INSERTED' END
FROM
Inserted I
UNION ALL
SELECT
D.Column1,
D.Column2,
'DELETED'
FROM Deleted D
WHERE NOT EXISTS (
SELECT * FROM Inserted
);
Wow, there are a lot of outright-wrong and semi-wrong (at least in being overcomplicated) answers given so far.

Answer 2

Assuming that both tables:
has an "Id" column as primary key.
has the same schema, except that history table has an extra "Status" column at the end.
You can create a trigger like this:
CREATE TRIGGER dbo.TableA_InsUpd
ON dbo.TableA
AFTER INSERT, UPDATE, DELETE
AS
BEGIN
Insert Into TableB
Select i.*, 'INSERTED'
From inserted i
Where not exists ( Select * From deleted d Where d.Id = i.Id )
Update B
Set [Status] = 'UPDATED',
Field1 = i.Field1,
Field2 = i.Field2
From TableB B
Inner Join inserted i On i.Id = B.Id
Where exists ( Select * From deleted d Where d.Id = i.Id )
Update B
Set [Status] = 'DELETED'
From TableB B
Inner Join deleted d On d.Id = B.Id
Where not exists ( Select * From inserted i Where i.Id = d.Id )
END
Here is a SqlFiddle with the complete code
(Note this will fail if a record Id is deleted and then inserted again)

Answer 3

Try this code
CREATE TRIGGER YouTriggerName
ON TableA
AFTER INSERT,DELETE,UPDATE
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
SET NOCOUNT ON;
-- Insert statements for trigger here
DECLARE #type NVarChar(15)=
CASE when not exists(SELECT * FROM inserted)
THEN 'Deleted'
WHEN exists(SELECT * FROM deleted)
THEN 'Updated'
ELSE
'Inserted'
END
/*
TableB should contains all the columns of TableA
OR tweak it to suit your need
*/
IF #type = 'Deleted' BEGIN
INSERT INTO TableB
SELECT *, #type Stat FROM deleted
END
ELSE BEGIN
INSERT INTO TableB
SELECT *, #type Stat FROM inserted
END
END
NOTE
You will get this error if TableB has identity on since we use (select *)
An explicit value for the identity column in table 'TableB' can only be specified when a column list is used and IDENTITY_INSERT is ON.

Answer 4

this is tested.here employee and employee have same table structure.0 means updated and 1=inserted,2=deleted
Alter trigger trgTest on dbo.employee
AFTER INSERT, UPDATE,Delete
as
Begin
Set noCount on
if exists(select e.id from deleted e inner join inserted i on e.ID=i.id )
Begin
insert into Employee1
select id,name,0 from inserted
End
else if exists(select e.id from Employee1 e inner join deleted d on e.ID=d.id)
Begin
insert into Employee1
select id,name,2 from deleted
End
else
Begin
insert into Employee1
select id,name,1 from inserted
End
End