Clearing/Removing a variable RSS

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  wreck_of_u

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  Clearing/Removing a variable

  Jul 04, 2007 07:22 AM|LINK

  Hi I have this code

  if (txtNewClusterName.Text != "")

  {

  //check if a duplicate exists

  Parameter PCluster = new Parameter();

  PCluster.Name = "PCluster";

  PCluster.Type = TypeCode.String;

  PCluster.DefaultValue = txtNewClusterName.Text;

  SqlDataSource SqlDS_ClusterValidate = new SqlDataSource();

  this.Controls.Add(SqlDS_ClusterValidate);

  SqlDS_ClusterValidate.ID = "SqlDS_ClusterValidate";

  SqlDS_ClusterValidate.ConnectionString = "my connection string here";

  SqlDS_ClusterValidate.SelectCommand = "SELECT [ClusterName] FROM [myClusterTable] WHERE ([ClusterName] = @PCluster)";

  SqlDS_ClusterValidate.SelectParameters.Add(PCluster);

  SqlDS_ClusterValidate.SelectCommandType = SqlDataSourceCommandType.Text;

   

  GridView gvClusterValidate = new GridView();

  gvClusterValidate.DataSource = SqlDS_ClusterValidate;

  gvClusterValidate.DataBind();

  if ((gvClusterValidate.Rows.Count != 0))

  {

  lblError.Text = "Cluster already exists!";

  }

  else

  {

  SQLDS_Cluster.Insert();

  lblError.Text = "";

  }

   

  }

   

  Yes, its for checking duplicates. It works fine, HOWEVER, I have the thing inside an AJAX UpdatePanel, and I get a "@PCluster is already declared" kind of error. Im suspecting that since I dont get a full postback, the variable doesnt get cleared/renewed.

  How do I manually remove/clear a variable manually?

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  codeasp

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  Re: Clearing/Removing a variable

  Jul 04, 2007 08:05 AM|LINK

   

  if (txtNewClusterName.Text != "")
  {
     // Clear the old message if any
     lblError.Text = ""
   
  
     // Now start checking for duplicates
  }

   

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  kipo

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  Re: Clearing/Removing a variable

  Jul 04, 2007 08:08 AM|LINK

  Try with this:

  SqlDS_ClusterValidate.SelectParameters.Clear();

  • Marked as answer by wreck_of_u on Jul 04, 2007 08:19 AM
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  wreck_of_u

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  119 Posts

  Re: Clearing/Removing a variable

  Jul 04, 2007 08:17 AM|LINK

  Hi, im having trouble with this one:

  Parameter PCluster = new Parameter();

  PCluster.Name = "PCluster"

  On full postback, it does ok. But if inside an UpdatePanel, I get an error: "The Variable Name @PCluster has already been declared. Variable names mus be unique whithin a query batch or stored procedure"

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  wreck_of_u

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  119 Posts

  Re: Clearing/Removing a variable

  Jul 04, 2007 08:19 AM|LINK

  kipo

  Try with this:

  SqlDS_ClusterValidate.SelectParameters.Clear();

   

  Thank you! Worked like a charm.

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  kipo

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  Re: Clearing/Removing a variable

  Jul 04, 2007 08:36 AM|LINK

  I'm glad I helped you, but you should try to use this code instead of your:

  using System.Data.SqlClient;

   

  if (txtNewClusterName.Text != "")
    {
     SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["your connection string name"].ConnectionString);
     SqlCommand cluster_Validate = con.CreateCommand();
     cluster_Validate.CommandText = "SELECT [ClusterName] FROM [myClusterTable] WHERE ([ClusterName] = @PCluster)";
     cluster_Validate.Parameters.Add("@PCluster", SqlDbType.NVarChar).Value = txtNewClusterName.Text;
     con.Open();
     int duplicate = cluster_Validate.ExecuteNonQuery();
     con.Close();
     if (duplicate > 0)
     {
      lblError.Text = "Cluster already exists!";
     }
     else
     {
      SQLDS_Cluster.Insert();
      lblError.Text = "";
     }
    }

  • Edited by kipo on Jul 04, 2007 08:37 AM