Adding primary key to existing dataSet

[gharabed]

How would I add a "primary key" to an existing variable of the type dataSet? I tried something like:

resultDataSet.Tables(0).PrimaryKey(0) = resultDataSet.Tables(0).Columns("ParticipantID")

where I only have one table in my dataset and the pk would be the "ParticipantID" column. However, I get an index out of range error. Any ideas?

 

[RiverGuy]

You have to set it to an array. Something like:

        Dim dc As DataColumn() = {resultDataSet.Tables(0).Columns("ParticipantID")}
        resultDataSet.Tables(0).PrimaryKey = dc