Copying Data From Multiple Tables To One Table

Hi,

I have 3 tables with the follwing schema
Table <Category>
{

UniqueID,
LastDate DateTime
}


Assume the follwing tables with data following the above schema

Table Cat1
{

1, D1
2, D2
3, D3
}
Table Cat2
{

2, D4
3,D5
4, D6
}
Table Cat3
{

1, D7
3,D8
5,D9
}

I have a Master and the schema is as follows
Table master
{

UniqueId,
Cat1 DateTime, -- This is same as the Table name
Cat2 DateTime, -- This is same as the Table name
Cat3 DateTime -- This is same as the Table name
}

After inserting the data from all these 3 tables, I want the my master table to look like this
Table Master
{

UniqueId cat1 cat2 Cat3
------------ --------- ------- -----------
1 D1 NULL D7
2 D2 D4 NULL
3 D3 D5 D8
4 NULL D6 NULL
5 NULL NULL D9
}


Please remember the column names will be same as that of table names

can any one pelase let me know the query t o acheive this

Thanks for your quick response
~Mohan Babu