CODEWITHSUNDEEP
sql-serverdatetimepropertiesnullablesqldatareader
Brian Var
Brian Var

Reputation: 6227

How to read back a nulllable DateTime using SQL Data Reader?

I've declared a nullable DateTime? NextUpdateproperty in my model and database.

I can update the DateTime value fine on my DB as it allows null for this field.

But when I try to get the value of NextUpdate field from the database using SQL Data Reader it bombs out because the value of NextUpdate is null.

I did try to init the NextUpdate value if it is null using the following assignment but the error is still thrown telling me that field is null:

NextUpdate = dataReader.GetDateTime(dataReader.GetOrdinal("NextUpdate")) != null ? dataReader.GetDateTime(dataReader.GetOrdinal("NextUpdate")) : DateTime.MinValue,

Error:

Data is Null. This method or property cannot be called on Null values -  at System.Data.SqlClient.SqlBuffer.get_DateTime()

Question:

Is there a short method of reading back and initializing a nullable **DateTime?** value?

Code:

using (IDataReader dataReader = db.ExecuteReader(dbCommand))
{
   if (dataReader.Read())
   {
      esc = new Escalation
      {
          NextUpdate = dataReader.GetDateTime(dataReader.GetOrdinal("NextUpdate")),
          RootCause = dataReader["RootCause"] != null ? dataReader["EM"].ToString() : ""
      };
   }
}

Property in Model:

    public DateTime? NextUpdate { get; set; }

Upvotes: 0

Views: 115

Answers (2)

nick_n_a
nick_n_a

Reputation: 206

Try following expression:

RootCause = (dataReader["RootCause"] is DBNull) ? (DateTime?)null :  (DateTime?)dataReader["RootCause"] ;

Upvotes: 0

Cee McSharpface
Cee McSharpface

Reputation: 8725

Compare the value against DBNull.Value instead of null:

NextUpdate = dataReader["NextUpdate"].Equals(DBNull.Value) ? (DateTime?)null : (DateTime?)dataReader["NextUpdate"]

(assuming that the NextUpdate member is a DateTime?)

Upvotes: 1

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