Question

I have a special ID column in a MySQL database. Some of the rows have the same special ids. Is there a way, when I’m selecting data, to specify if I’ve already grabbed a row with that special id to ignore the next row with that same special id?

Answer 1

You haven’t give us much to go on (such as schema, sample inputs, expected outputs etc), however, what you seek might entail something akin to:

Select ....
From MyTable
    Join    (
            Select Min( PrimarykeyColumn ) As Pk
                , SpecialId
            From MyTable
            Group By SpecialId
            ) As SpecialIdValues
        On SpecialIdValues.Pk = MyTable.PrimarykeyColumn

In this scenario, I’m arbitrarily chosing the lowest Primary Key value for each of the SpecialId values.