Invalid Date DateTime?
I have a class with the following code
public cCase(string pCaseNo, string pMode)
{
if (pMode == "new")
{
this._caseNo = Validate_CaseNo(pCaseNo);
}
if (pMode == "existing")
{
try
{
int intValidatedCaseNo = Validate_CaseNo(pCaseNo);
string sqlText = "SELECT * FROM tblCases WHERE CaseNo = @CaseNo;";
string strConnection = cConnectionString.BuildConnectionString();
SqlConnection linkToDB = new SqlConnection(strConnection);
linkToDB.Open();
SqlCommand sqlCom = new SqlCommand(sqlText, linkToDB);
sqlCom.Parameters.Add("@CaseNo", SqlDbType.Int);
sqlCom.Parameters["@CaseNo"].Value = intValidatedCaseNo;
SqlDataReader caseReader = sqlCom.ExecuteReader();
if (caseReader.HasRows)
while (caseReader.Read())
{
this._claimant = caseReader["Claimant"].ToString();
this._defendant = caseReader["Defendant"].ToString();
this._caseType = caseReader["CaseType"].ToString();
this._occupation = caseReader["Occupation"].ToString();
this._doa = (DateTime?)caseReader["DOA"];
this._dateClosed = (DateTime?)caseReader["DateClosed"];
this._dateSettled = (DateTime?)caseReader["DateSettled"];
this._dateInstructed = (DateTime?)caseReader["DateInstructed"];
this._status = caseReader["Status"].ToString();
this._instructionType = caseReader["InstructionType"].ToString();
this._feeEstimate = (decimal?)caseReader["FeeEstimate"];
this._amountClaimed = (decimal?)caseReader["AmountClaimed"];
this._amountSettled = (decimal?)caseReader["AmountSettled"];
this._caseManager = caseReader["CaseManager"].ToString();
}
caseReader.Close();
linkToDB.Close();
linkToDB.Dispose();
}
catch (Exception eX)
{
throw new Exception("Error finding case" + Environment.NewLine + eX.Message);
}
}
}
However Datetime? cleared from "Invalid Cast". I checked the SQL database and the field is storing valid dates So I cannot figure out why, since I am fetching information via DataReader into my application, datetime fields are calling Invalid Cast.
Please, help.
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The fields DateTime
probably contain a value DBNull
that you cannot directly convert.
However, for convenience, I would use an extension method on yours DataReader
.
public static class DataReaderExtensions
{
public static DateTime? ReadNullableDateTime(this IDataReader reader, string column)
{
return reader.IsDBNull(column) ? (DateTime?)null : reader.GetDateTime(column);
}
}
//Using
this._dateInstructed = CaseReader.ReadNullableDateTime("DateInstructed");
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I often practice DBNull.Value
...
Therefore I use this method which will return the object value or default value for the given value type if the object value DBNull.Value
.
public static object GetValueOrDefault(object value, Type type)
{
if (value != DBNull.Value)
return value;
if (type.IsValueType == false)
return null;
Array array = Array.CreateInstance(type, 1);
return array.GetValue(0);
}
Using:
GetValueOrDefault(dataRecord.GetValue(fieldIndex), dataRecord.GetFieldType(fieldIndex)
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