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

Question

what is the best way to check if a Data Table has a null value in it ?

Most of the time in our scenario, one column will have all null values.

(This datatable is returned by a 3rd party application - we are trying to put a valiadation before our application processes the data-table)

Answer 1

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

---

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();