Question: Convert custom DateTime object to DateTime on insert

Hello,

I am using t4 model generation and all of the DateTime properties have been converted to NodaTime.LocalDateTime.

When I am getting the data from the DB I am using this convertor successfully:

LinqToDB.Mapping.MappingSchema.Default.SetConverter<DateTime, NodaTime.LocalDateTime>(timeStamp =>
			new NodaTime.LocalDateTime(timeStamp.Year, timeStamp.Month, timeStamp.Day, timeStamp.Hour,
			timeStamp.Minute, timeStamp.Second, timeStamp.Millisecond));

The issue is when I try to submit data:

UserSession session = new UserSession
           {
               CreatedOn = NodaTime.LocalDateTime.FromDateTime(DateTime.Now),
           };

using (var db = new DBContext())
           {
                   await db.InsertAsync(session);
           }

The error is:

ArgumentException: No mapping exists from object type NodaTime.LocalDateTime to a known managed provider native type.
System.Data.SqlClient.MetaType.GetMetaTypeFromValue(Type dataType, object value, bool inferLen, bool streamAllowed)
System.Data.SqlClient.MetaType.GetMetaTypeFromType(Type dataType)
System.Data.SqlClient.SqlParameter.GetMetaTypeOnly()
lambda_method(Closure , IDbDataParameter )
LinqToDB.DataProvider.SqlServer.SqlServerDataProvider.SetParameter(DataConnection dataConnection, IDbDataParameter parameter, string name, DbDataType dataType, object value)
LinqToDB.Data.DataConnection+QueryRunner.AddParameter(DataConnection dataConnection, ICollection<IDbDataParameter> parms, string name, SqlParameter parm)
LinqToDB.Data.DataConnection+QueryRunner.GetParameters(DataConnection dataConnection, PreparedQuery pq)
LinqToDB.Data.DataConnection+QueryRunner.SetQuery(DataConnection dataConnection, IQueryContext queryContext, int startIndent)
LinqToDB.Data.DataConnection+QueryRunner.SetQuery()
LinqToDB.Linq.QueryRunnerBase.SetCommand(bool clearQueryHints)
LinqToDB.Data.DataConnection+QueryRunner.ExecuteNonQueryAsync(CancellationToken cancellationToken)
LinqToDB.Linq.QueryRunner.NonQueryQueryAsync(Query query, IDataContext dataContext, Expression expression, object[] ps, object[] preambles, CancellationToken cancellationToken)
LinqToDB.Linq.QueryRunner+Insert<T>.QueryAsync(IDataContext dataContext, T obj, InsertColumnFilter<T> columnFilter, string tableName, string serverName, string databaseName, string schemaName, CancellationToken token)

And the convertors that I have tried are:

LinqToDB.Mapping.MappingSchema.Default.SetDataType(typeof(LocalDateTime), LinqToDB.DataType.DateTime);
LinqToDB.Mapping.MappingSchema.Default.SetDataType(typeof(LocalDateTime), LinqToDB.SqlQuery.SqlDataType.DateTime);

LinqToDB.Mapping.MappingSchema.Default.SetConverter<NodaTime.LocalDateTime, DataParameter>(timeStamp =>
new DataParameter
{
	Value = new DateTime(timeStamp.Year, timeStamp.Month, timeStamp.Day, timeStamp.Hour,
timeStamp.Minute, timeStamp.Second, timeStamp.Millisecond),
        //Value = DateTime.Now,
	DataType = LinqToDB.DataType.DateTime
});

LinqToDB.Mapping.MappingSchema.Default.SetConverter<NodaTime.LocalDateTime, DateTime>(timeStamp =>
new DateTime(timeStamp.Year, timeStamp.Month, timeStamp.Day, timeStamp.Hour,
timeStamp.Minute, timeStamp.Second, timeStamp.Millisecond));

LinqToDB.Mapping.MappingSchema.Default.SetValueToSqlConverter
	(typeof(NodaTime.LocalDateTime), (sb, dt, v) =>
	{
		var d = (NodaTime.LocalDateTime)v;
		var d1 = new DateTime(d.Year, d.Month, d.Day, d.Hour,
		d.Minute, d.Second, d.Millisecond);

		sb.Append("'").Append(d1.ToString()).Append("'");
		//sb.Append("'").Append(d1).Append("'");
	}
	);

LinqToDB.Mapping.MappingSchema.Default.SetConverter<NodaTime.LocalDateTime, DataParameter>(timeStamp =>
new DataParameter
{
	Value = new DateTime(timeStamp.Year, timeStamp.Month, timeStamp.Day, timeStamp.Hour,
timeStamp.Minute, timeStamp.Second, timeStamp.Millisecond).ToString(),
	DataType = LinqToDB.DataType.NVarChar
});

Could you please give some directions of what am I missing here?

I have tried on Linq2DB.SqlServer versions 3.1.2 and 3.1.5

Thank you.

[carloscs]

I’ve been testing Linq2db [mappings, optimistic locking,…] and this is working for me.

Setup:

LocalDateTimeToDatetimeConverter.RegisterConverters(schema);

Code:

public static class LocalDateTimeToDatetimeConverter {

    public static void RegisterConverters(MappingSchema schema) {
        schema.SetConverter<LocalDateTime?, DataParameter>(ldt => new DataParameter { Value = ldt?.ToDateTimeUnspecified() });
        schema.SetConverter<LocalDateTime, DataParameter>(ldt => new DataParameter { Value = ldt.ToDateTimeUnspecified() });

        schema.SetConverter<LocalDateTime?, DateTime?>(ldt => ldt?.ToDateTimeUnspecified());
        schema.SetConverter<LocalDateTime?, DateTime>(ldt => ldt.LocalDateTimeToDateTime());
        schema.SetConverter<LocalDateTime, DateTime?>(ldt => ldt.ToDateTimeUnspecified());
        schema.SetConverter<LocalDateTime, DateTime>(ldt => ldt.ToDateTimeUnspecified());

        schema.SetConverter<DateTime?, LocalDateTime?>(dt => dt == null ? (LocalDateTime?) null : LocalDateTime.FromDateTime(dt.Value));
        schema.SetConverter<DateTime?, LocalDateTime>(dt => dt.DateTimeToLocalDateTime());
        schema.SetConverter<DateTime, LocalDateTime?>(dt => LocalDateTime.FromDateTime(dt));
        schema.SetConverter<DateTime, LocalDateTime>(LocalDateTime.FromDateTime);

        schema.SetValueToSqlConverter(typeof(LocalDateTime?), ConverterToSql);
    }


    static DateTime LocalDateTimeToDateTime(this LocalDateTime? dateTime) {
        if (dateTime == null) {
            throw new InvalidOperationException("Can't convert null to LocalDateTime.");
        }
        return dateTime.Value.ToDateTimeUnspecified();
    }


    static LocalDateTime DateTimeToLocalDateTime(this DateTime? dateTime) {
        if (dateTime == null) {
            throw new InvalidOperationException("Can't convert null to LocalDateTime.");
        }
        return LocalDateTime.FromDateTime(dateTime.Value);
    }


    static void ConverterToSql(StringBuilder sb, SqlDataType tp, object v) {
        if (v == null) {
            sb.Append("NULL");
        }
        else {
            // todo: format date
            sb.Append($"TO_DATE('{v}', '%Y-%m-%d %H:%M:%S.%F5')");
        }
    }

}

[thedoomx]

Hi @carloscs

The provided solution worked perfectly for me.

Thank you!