How to convert a value if it's null

Question

I am using C#

Convert.ToDateTime(rdr["Termination_Date"])

rdr is defined as

OracleDataReader rdr = cmd.ExecuteReader();

The Termination_Date field in the table maybe null. How do I check if it's null and set a date like 01/01/0001

Answer 1

If you have to access the column by name, you can compare against DBNull.Value with something like a ternary statement to pick between DateTime.MinValue (1/1/0001) and the result of converting the non-null value.

OracleDataReader rdr = cmd.ExecuteReader();

DateTime terminationDate = rdr["Termination_Date"] == DBNull.Value
    ? DateTime.MinValue
    : Convert.ToDateTime(rdr["Termination_Date"]);

You can do this more concisely with OracleDataReader.IsDBNull() and OracleDataReader.GetDateTime() if you know the column index (assume that our desired value is the first column in the result).

OracleDataReader rdr = cmd.ExecuteReader();

DateTime terminationDate = rdr.IsDBNull(0)
    ? DateTime.MinValue
    : rdr.GetDateTime(0);