A More Complicated Case Of Insertion Filtering By More Than Two Fields

Hi,

I posted a problem some hours ago. I found that the solution that l was given by Karolyn was great, but at that time I didn't realize that my problem was a little bit more complicated. I'll rephrase my problem:

I need to insert some registers in a table. These registers have three fileds: col1, col2 and col3. I don't want to insert a register if in the table already exists a row with the col1, col2 and col3 combination of that register. These fields are PK, but I don't want to get errors. The problem is that I'm inserting a field that belongs also to the destination table. How can I filter a "destination" table by two fields in this case?

This the table1:

create table table1(
col1 int not null,
col2 int not null,
col3 int not null,
constraint PK_table1 primary key (col1, col2, col3)
)


Here's my "insert" code:

INSERT INTO table1
SELECT table2.col1, table3.col2, table1.col3
FROM table2, table3
WHERE table2.col1 = table3.col1


The third field in the SELECT now refers also to table1. Witch conditions should I add to avoid repetitions in table1 (avoiding also erroing)

Thanks

Federico