Inserting the diff rows into a table

Hi,

I have two tables as follows

Table TempTab

{

CatId varchar(20),

lastupdate Datetime

}

Table MainTab

{

CatId varchar(20),

lastupdate Datetime

}

and the data in those tables are as follows

Table TempTab

{

CatId LastUpdate

Cat1 D1

Cat2 D2

Cat3 D3

Cat4 D4

}

Table MainTab

{

CatId LastUpdate

Cat1 D1

Cat3 D3

Cat5 D5

}

I need a query to insert the differences into the MinTab, i mean to say the fincal MainTab should look like as follows

Table MainTab

{

CatId LastUpdate

Cat1 D1

Cat2 D2

Cat3 D3

Cat4 D4

Cat5 D5

}

can any one please let me know the query

Thanks alot

~Mohan

INSERT INTO MainTab(CatID, LastUpdate)
SELECT CatID, LastUpdate FROM TempTab
WHERE CatID NOT IN(SELECT CatID FROM MainTab WHERE atID IS NOT NULL)
|||

Here it is,

Code Snippet

Create Table #temptab (

[CatId] Varchar(100) ,

[LastUpdate] Varchar(100)

);

Insert Into #temptab Values('Cat1','D1');

Insert Into #temptab Values('Cat2','D2');

Insert Into #temptab Values('Cat3','D3');

Insert Into #temptab Values('Cat4','D4');

Create Table #maintab (

[CatId] Varchar(100) ,

[LastUpdate] Varchar(100)

);

Insert Into #maintab Values('Cat1','D1');

Insert Into #maintab Values('Cat3','D3');

Insert Into #maintab Values('Cat5','D5');

Code Snippet

Insert Into #maintab

Select * from #temptab t

Where not exists

(

select 1 from #maintab m

where m.catid=t.catid

)