how to remove duplicate rows using SQL query in Microsoft SQL server.
basically my requirement is i have a table with no constraint.
Now that table contains lots of duplicate data rows.
how can i remove all duplicate rows in one sort and add constraint in that table.
In sql we can use below:
to delete duplicates Firstly you need to find out a column which can be a primary key for that table.use that column in below query
delete from table e where rowid not in (select max(rowid) from table e1 where e.primarykeycolumn=e1.primarykeycolumn);
based on your requirement you can delete latest record or old record by changing max,min in above query.