{"Operator '=' is not defined for type 'DBNull' and type 'Double'."}

[rocks_lp]

when a user inputs a value into a text box, i am searching that value in my dataset. although the number that i entered is in my dataset, i am getting this excemption.
please help me

 

[JuggaloBrotha]

What you should do when dealing with null values is use the 'Is DBNull.Value' because null's don't equal anything (not even 'Nothing').

So what you can do is first check that the data isn't null then check to see if the values match:

If DataSetValue IsNot DBNull.Value AndAlso DataSetValue = SomeValue Then
  'Value isn't a DB Null and is equal to whatever condition(s)
End If

 

[rocks_lp]

thank you
JuggaloBrotha
your answer solved the problem

 

[jmcilhinney]

You certainly can do as JB suggests but if you're getting a value from a DataReader or a DataRow then they both have methods for detecting null values:

If Not myDataReader.IsDBNull(columnIndex) AndAlso myDataReader.GetDouble(columnIndex) = myDouble Then

If Not myDataRow.IsNull(columnName) AndAlso CDbl(myDataRow(columnName)) = myDouble Then