Create Unique Constraint

UniqueConstraint Class represents a restriction on a set of columns in which all values must be unique.

Following example show how to create Unique Constraint

Sub Main()

Dim objmyTable As DataTable = New DataTable

objmyTable.Columns.Add("Id", GetType(Integer))

objmyTable.Columns.Add("Name", GetType(String))

Dim uniqueConstraint As Data.UniqueConstraint = New Data.UniqueConstraint("UniqueConstraint", objmyTable.Columns("Id"))

objmyTable.Constraints.Add(uniqueConstraint)

Try

objmyTable.Rows.Add(132, "mukesh")

objmyTable.Rows.Add(123, "vinay")

objmyTable.Rows.Add(132, "ashish")

Catch ex As Exception

Console.WriteLine(vbLf & "Error: {0}", ex.Message)

End Try

Console.WriteLine(vbLf & "Press any key to continue.")

Console.ReadLine()

End Sub

Output :