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Sandiya
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Compare two tables

Hi All,

I want a asp.net ,vb code to compare two datatables and dynamically generate alter table for the missing columns .
Visual Basic.NETASP.NET

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Sandiya

8/22/2022 - Mon
Dirk Haest

You can use linq. Small example attached.

    Private Sub compareTables()
        Dim Table1 As DataTable = New DataTable("Customers")
        Table1.Columns.Add("Name", Type.GetType("System.String"))
        Table1.Columns.Add("Firstname", Type.GetType("System.String"))
        Table1.Columns.Add("Street", Type.GetType("System.String"))
        Table1.Columns.Add("HouseNumber", Type.GetType("System.String"))
        Table1.Columns.Add("PostalCode", Type.GetType("System.String"))

        Dim Table2 As DataTable = New DataTable("Customers2")
        Table2.Columns.Add("Name", Type.GetType("System.String"))
        Table2.Columns.Add("Firstname", Type.GetType("System.String"))
        Table2.Columns.Add("State", Type.GetType("System.String"))

        Dim firstquery = From col In Table1.Columns Select col.columnName
        Dim notinsecondtable = From col In Table2.Columns Where Not firstquery.Contains(col.columnName)
    End Sub

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The last query will tell you that you have a column (namely state) in your second datatable that is not in your first datatable
ASKER CERTIFIED SOLUTION
Nasir Razzaq

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Sandiya

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Thanks All
Your help has saved me hundreds of hours of internet surfing.
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