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c#datatablenulldatarow
Nick Josevski
Nick Josevski

Reputation: 4216

C# DataTable ItemArray returns '{}' - how can I test for null value?

I have a DataTable resultSet; - I'm trying to check fields for null, but get an '{}' (empty-set ?) object back. Searches involving "{}" aren't yielding any appropriate solutions.

This is the code that isn't working as expected when the "fk_id" field is null:

if (resultSet.Rows[0].ItemArray[resultSet.Columns.IndexOf("fk_id")] == null)
{
   //never reaches here
}

Note: using an int index instead of the Columns.IndexOf() isn't the issue.

Also does the "{}" have some other name in C#?

Upvotes: 11

Views: 26543

Answers (3)

Khalid Rafique
Khalid Rafique

Reputation: 161

Please use:

dataTable.Select("FieldName is NULL")

this will give you the DataRows with null values in FieldName column.

Upvotes: -2

Adei
Adei

Reputation: 1

try
{
    if (DT.Rows[0][0] != null)
    {      
      //your code
    }    
}    
catch    
{    
    MessageBox.Show("AUTHANICATION FAILED.");    
}

Upvotes: -2

Matt Hamilton
Matt Hamilton

Reputation: 204229

To check a column for DBNull in a DataSet, you can use the IsNull method:

if (resultSet.Rows[0].IsNull("fk_id"))

Your comparison against null is probably failing because DataSets don't use null to represent a "database NULL" value - they use DBNull.Value. If you need your code to work the way you've presented it, try this:

if (resultSet.Rows[0].ItemArray[resultSet.Columns.IndexOf("fk_id")] == DBNull.Value)

Upvotes: 19

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