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need help on checking an existing data in a database

Question

User-1974373719 posted

I have this class that inserts data into a database and works fine. I am inserting the data through formview using objectdataasource.I need help on checking

the existance of data before being inserted ie if data being inserted exist should bring a popup saying data exist.

<System.ComponentModel.DataObjectMethodAttribute(System.ComponentModel.DataObjectMethodType.Insert, True)> _
    Public Function AddtblVessels(ByVal vesselName As String) As Boolean

        Dim vessels As New SAMI.tblVesselsDataTable()
        Dim vessel As SAMI.tblVesselsRow = vessels.NewtblVesselsRow()

        vessel.VesselName = vesselName

        vessels.AddtblVesselsRow(vessel)
        Dim rowsAffected As Integer = Adapter.Update(vessels)
        Return rowsAffected = 1
    End Function

Tuesday, January 29, 2013 6:25 AM

Answers

User-1034726716 posted

This one uses the traditional ado.net but I hope this will give you an idea:

private void UpdateInfo(sting strValue1, int region)
{
       SqlConnection conn = new SqlConnection("YOUR CONNECTION STRING");
       string sql = "UPDATE TableName SET ColumnName1 = @val1 WHERE RegionID = @region";
       try
       {
        conn.Open();
           SqlCommand cmd = new SqlCommand(sql, conn);
           cmd.Parameters.AddWithValue("@Val1", strValue1);
           cmd.Parameters.AddWithValue("@region", region);
           cmd.CommandType = CommandType.Text;
           cmd.ExecuteNonQuery();
       }
       catch (System.Data.SqlClient.SqlException ex)
       { 
            //catch exception here
       }
       finally
       {
          conn.Close();
       }
}

private void InsertInfo(string strValue1, string strValue2, string strValue3)
{

       SqlConnection conn = new SqlConnection("YOUR CONNECTION STRING");
       string sql = "INSERT INTO TableName (ColumnName1,ColumnName2,ColumnName3) VALUES (@Val1,@Val2,@Val3)";
       try
       {
           conn.Open();
           SqlCommand cmd = new SqlCommand(sql, conn);
           cmd.Parameters.AddWithValue("@Val1", strValue1);
           cmd.Parameters.AddWithValue("@Val2", strValue2);
           cmd.Parameters.AddWithValue("@Val3", strValue3);
           cmd.CommandType = CommandType.Text;
           cmd.ExecuteNonQuery();
       }
       catch (System.Data.SqlClient.SqlException ex)
       {
              //catch exception here
       }
       finally
       {
       conn.Close();
       }


}
private void CheckIfExist(int region)
{
    SqlConnection conn = new SqlConnection("Your Connection String");
    DataTable dt = new DataTable();
    try
    {
        conn.Open();
       

        String sql = "SELECT * FROM region WHERE RegionID = @region";
        SqlCommand cmd = new SqlCommand(sql, conn);
        cmd.Parameters.AddWithValue("@region",region);
        SqlDataAdapter ad = new SqlDataAdapter(cmd);
        ad.Fill(dt);


        if (dt.Rows.Count > 0)
        {
            Label1.Text = "REGION ID Exist!";
            //CALL the UPDATE method here and pass its parameter values
            UpdateInfo("Value1",region);
        }
        else
        {
            Label1.Text = "REGION ID NOT FOUND!";
            //CALL the INSERT method here and pass its parameter values
            InsertInfo("value1","Value2","Value3");
        }
    }
    catch (System.Data.SqlClient.SqlException ex)
    {
          //catch exception here
    }
    finally
    {
       conn.Close();
    }
       
}

protected void Button1_Click(object sender, EventArgs e)
{
    string region = 10;
    CheckIfExist(region);
}

Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM

Tuesday, January 29, 2013 6:30 AM

Answered by:

need help on checking an existing data in a database

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