Question

how to detect/remove duplicate entries from a database in a table where there is no primary key ?

[If we use ‘DISTINCT’ how do we know which record is the correct one and duplicate one ? ]

Answer 1

delete f
from
(
    select ROW_NUMBER() 
        over (partition by 
            YourFirstPossibleDuplicateField,
            YourSecondPossibleDuplicateField
            order by WhateverFieldYouWantSortedBy) as DelId
    from YourTable
) as f
where DelId > 1