Check Bound Datatable for Null Value Vb.Net

check bound datatable for null value vb.net

use DbNull.Value:

   If Not DbNull.Value.Equals(dt.Rows(1).Item(1).value) Then 
      ' do something
   Else 
      ' do something else 
   End If

or use

If dt.Rows(1).Item(1).value=DbNull.Value

Best way to check if a Data Table has a null value in it

Try comparing the value of the column to the DBNull.Value value to filter and manage null values in whatever way you see fit.

foreach(DataRow row in table.Rows)
{
    object value = row["ColumnName"];
    if (value == DBNull.Value)
        // do something
    else
        // do something else
}

More information about the DBNull class

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If you want to check if a null value exists in the table you can use this method:

public static bool HasNull(this DataTable table)
{
    foreach (DataColumn column in table.Columns)
    {
        if (table.Rows.OfType<DataRow>().Any(r => r.IsNull(column)))
            return true;
    }

    return false;
}

which will let you write this:

table.HasNull();

How to check for a Null value in VB.NET

If you are using a strongly-typed dataset then you should do this:

If Not ediTransactionRow.Ispay_id1Null Then
    'Do processing here
End If

You are getting the error because a strongly-typed data set retrieves the underlying value and exposes the conversion through the property. For instance, here is essentially what is happening:

Public Property pay_Id1 Then
   Get
     return DirectCast(me.GetValue("pay_Id1", short)
   End Get
   'Abbreviated for clarity
End Property

The GetValue method is returning DBNull which cannot be converted to a short.

c# check the empty or null value in all datatable values

Use the indexer

dt.Rows[i][j] != null && string.IsNullOrEmpty(dt.Rows[i][j].ToString())

How To Show A Null Value From Database In TextBox In VB.NET

If I'm reading your question right, it sounds like you could just do this:

txtFine_amt.Text = dt.Rows(0).Item("fine_amt").ToString()

For null values, ToString() will always just return an empty string.

Checking for null value with DataTable.Select

CopyToDataTable should fix the issue:

LV_Employees.DataSource = employees.Select("Name LIKE '%" + TB_Search.Text + "%'")
    .CopyToDataTable();
LV_Employees.DataBind();

Simple way to convert dbNull to a string in VB.NET

For string types you can directly use it this way dt.rows(0).item(0).ToString(), without the If condition

adap.Fill(dt)

Dim someStr As String = "The first column of the first row returned: " & dt.rows(0).item(0).ToString()

MsgBox(somestr)

i.e. you can completely omit the if statement. As per MSDN any DBNull value will be converted to EmptyString with .ToString()

Also check this SO post Conversion from type 'DBNull' to type 'String'

However, for non-string database column types such as integers, doubles you must apply checks using IsDBNull to avoid any exceptions.

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