multi-field primary key

I have a table (table1) that has a bunch of fields....

[field1]
[field2]
[field3]
[field4]
[field5]

None of these fields are unique, but if I combine them, then they are
unique.

I know there is a way to make multi-field primary keys, but when I try
I get an that field1 is not unique, which I already know,

How can I make a multi-field primary key?

thanks

ALTER TABLE table1
ADD CONSTRAINT pk_table1 PRIMARY KEY (col1, col2, col3, col4, col5) ;

Tip: "column" and "row" are the terms usually preferred over "field"
and "record" when discussing SQL databases. Some people will argue that
there are quite different concepts attached to the different names and
that the distinction is a very important one. Others use the names
interchangeably without worrying to much about the formal definitions.
Still, you won't be called wrong if you stick with the terms "column"
and "row". :-)

Hope this helps.

--
David Portas
SQL Server MVP
--

thanks, I try it