Creating primary key on the existing table with data

[ahlone]

Hi,

Currently, I have a table with no primary key, but, data are already loaded. So, I am trying to create the primary key on one of the columns with Enterprise Manager, but, no luck. Right now, it's allowing duplicate records to be inserted to the table.

Thanks

 

[bborissov]

You can't create primary key if you have duplicateed info in the field you want to use as PK. First you must delete/Change records with duplicated info.
Check for duplicate:

SELECT Field1, field2, Count(*) AS Cnt FROM MyTable
GROUP BY Field1, field2
HAVING Cnt > 1

where field1 and field2 are fields PK based on.

Borislav Borissov