4.5.10.5 Handling NULL Dates

The .NET DateTime data type cannot handle NULL values. As such, when assigning values from a query to a DateTime variable, you must first check whether the value is in fact NULL.

When using a MySqlDataReader, use the .IsDBNull method to check whether a value is NULL before making the assignment:

C# Code Example

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if (! myReader.IsDBNull(myReader.GetOrdinal("mytime")))
    myTime = myReader.GetDateTime(myReader.GetOrdinal("mytime"));
else
    myTime = DateTime.MinValue;

Visual Basic Code Example

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If Not myReader.IsDBNull(myReader.GetOrdinal("mytime")) Then
    myTime = myReader.GetDateTime(myReader.GetOrdinal("mytime"))
Else
    myTime = DateTime.MinValue
End If

NULL values will work in a data set and can be bound to form controls without special handling.