Index on DataTable ?

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  • fniles
    #1

    Index on DataTable ?

    Can I create an index on a DataTable ?
    On the following DataTable, I would like to create index on "Price", can I
    do that ?
    Thank you.

    Dim DT As New DataTable

    DT.Columns.Add( "Price", GetType(System. Int32))
    DT.Columns.Add( "ID", GetType(System. Int32))
    DT.Columns.Add( "Vol", GetType(System. Int32))

    Dim r As DataRow = DT.NewRow
    r.Item(0) = 99
    r.Item(1) = 1234
    r.Item(2) = 350
    r.Item(3) = 1
    DT.Rows.Add(r)

    r = DT.NewRow
    r.Item(0) = 98
    r.Item(1) = 1233
    r.Item(2) = 300
    r.Item(3) = 1
    DT.Rows.Add(r)

    r = DT.NewRow
    r.Item(0) = 97
    r.Item(1) = 1230
    r.Item(2) = 375
    r.Item(3) = 1
    DT.Rows.Add(r)

    r = DT.NewRow
    r.Item(0) = 96
    r.Item(1) = 1231
    r.Item(2) = 250
    r.Item(3) = 1
    DT.Rows.Add(r)
    DT.AcceptChange s()


    Tags: None
    • =?Utf-8?B?S2VycnkgTW9vcm1hbg==?=
      #2
      RE: Index on DataTable ?

      fniles,

      No, I don't believe you can add an index to a datatable.

      Keep in mind that datasets/datatables are not the same as an in-memory sql
      database and trying to treat them as such will only lead to frustration.

      Having said that, if you need an index for performance while selecting, you
      might look into the dataview and its find methods. It will index on whatever
      you set as its sort column.

      Kerry Moorman

      "fniles" wrote:
      Can I create an index on a DataTable ?
      On the following DataTable, I would like to create index on "Price", can I
      do that ?
      Thank you.
      >
      Dim DT As New DataTable
      >
      DT.Columns.Add( "Price", GetType(System. Int32))
      DT.Columns.Add( "ID", GetType(System. Int32))
      DT.Columns.Add( "Vol", GetType(System. Int32))
      >
      Dim r As DataRow = DT.NewRow
      r.Item(0) = 99
      r.Item(1) = 1234
      r.Item(2) = 350
      r.Item(3) = 1
      DT.Rows.Add(r)
      >
      r = DT.NewRow
      r.Item(0) = 98
      r.Item(1) = 1233
      r.Item(2) = 300
      r.Item(3) = 1
      DT.Rows.Add(r)
      >
      r = DT.NewRow
      r.Item(0) = 97
      r.Item(1) = 1230
      r.Item(2) = 375
      r.Item(3) = 1
      DT.Rows.Add(r)
      >
      r = DT.NewRow
      r.Item(0) = 96
      r.Item(1) = 1231
      r.Item(2) = 250
      r.Item(3) = 1
      DT.Rows.Add(r)
      DT.AcceptChange s()
      >
      >
      >

        Comment

        • Brian Gideon
          #3
          Re: Index on DataTable ?

          On Sep 18, 8:41 am, "fniles" <fni...@pfmail. comwrote:
          Can I create an index on a DataTable ?
          On the following DataTable, I would like to create index on "Price", can I
          do that ?
          Thank you.
          >
          Dim DT As New DataTable
          >
          DT.Columns.Add( "Price", GetType(System. Int32))
          DT.Columns.Add( "ID", GetType(System. Int32))
          DT.Columns.Add( "Vol", GetType(System. Int32))
          >
          Dim r As DataRow = DT.NewRow
          r.Item(0) = 99
          r.Item(1) = 1234
          r.Item(2) = 350
          r.Item(3) = 1
          DT.Rows.Add(r)
          >
          r = DT.NewRow
          r.Item(0) = 98
          r.Item(1) = 1233
          r.Item(2) = 300
          r.Item(3) = 1
          DT.Rows.Add(r)
          >
          r = DT.NewRow
          r.Item(0) = 97
          r.Item(1) = 1230
          r.Item(2) = 375
          r.Item(3) = 1
          DT.Rows.Add(r)
          >
          r = DT.NewRow
          r.Item(0) = 96
          r.Item(1) = 1231
          r.Item(2) = 250
          r.Item(3) = 1
          DT.Rows.Add(r)
          DT.AcceptChange s()
          Not really. One exception is the PK which is indexed.

            Comment

            • fniles
              #4
              Re: Index on DataTable ?

              Thank you
              How can you create PK on the dataTable ?


              "Brian Gideon" <briangideon@ya hoo.comwrote in message
              news:b1a45494-8189-4182-b01c-4a1e00309bff@b3 8g2000prf.googl egroups.com...
              On Sep 18, 8:41 am, "fniles" <fni...@pfmail. comwrote:
              Can I create an index on a DataTable ?
              On the following DataTable, I would like to create index on "Price", can I
              do that ?
              Thank you.
              >
              Dim DT As New DataTable
              >
              DT.Columns.Add( "Price", GetType(System. Int32))
              DT.Columns.Add( "ID", GetType(System. Int32))
              DT.Columns.Add( "Vol", GetType(System. Int32))
              >
              Dim r As DataRow = DT.NewRow
              r.Item(0) = 99
              r.Item(1) = 1234
              r.Item(2) = 350
              r.Item(3) = 1
              DT.Rows.Add(r)
              >
              r = DT.NewRow
              r.Item(0) = 98
              r.Item(1) = 1233
              r.Item(2) = 300
              r.Item(3) = 1
              DT.Rows.Add(r)
              >
              r = DT.NewRow
              r.Item(0) = 97
              r.Item(1) = 1230
              r.Item(2) = 375
              r.Item(3) = 1
              DT.Rows.Add(r)
              >
              r = DT.NewRow
              r.Item(0) = 96
              r.Item(1) = 1231
              r.Item(2) = 250
              r.Item(3) = 1
              DT.Rows.Add(r)
              DT.AcceptChange s()
              Not really. One exception is the PK which is indexed.


                Comment

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