So using the OracleDataReader by itself works fine.

using(OracleConnection con = new OracleConnection(connString))
{
using(OracleCommand cmd = con.CreateCommand())
{
con.Open();
cmd.BindByName = true;

cmd.CommandText =@"SELECT 12356789.123456789012345678901234567890 Test FROM dual";

try
{

OracleDataReader reader = cmd.ExecuteReader();
List<decimal> results = new List<decimal>();

while (reader.Read())
{
results.Add(OracleDecimal.SetPrecision(reader.GetOracleDecimal(0), 27).Value);
}

reader.Dispose();
return Ok(results);
}catch(Exception ex)
{

}
}
}

If i instead use ODBC connection (and changing all int? and short? to decimal? in the created models) will work it seems like. but if i try use that same odbc connection when i convert the datawindows, snapdevelop crashes. Im using snapdevelop 2019 R2.

Hi Per, 

Currently, SnapObjects support decimal data type of up to 28 digit precision. But it doesn’t support OracleDecimal. When using SnapObjects, it doesn’t support manually changing the data type from decimal to OracleDecimal for the model in SnapDevelop. What precision do you need in your case? We suggest that you submit an enhancement request through our ticket system (https://www.appeon.com/standardsupport/newbug).

BTW, SnapDevelop R2 doesn’t support connecting to Oracle using ODBC. Please choose “Oracle” for “Database provider” on the Database Connection window for connection to Oracle. See the screenshot below.

Regards,

David

Mabye let me rephrase it. We are prefectly fine with 28 digits precision the problem really is that it crashes when trying to map oracles large numbers. We have alot of datawindows in our desktop  application that we would like to convert to webapi but we cant be rounding every oracle number in every datawindow just to be safe. (i know even if snapdevelop didnt support oracle odbc , the decimal numbers never crashed atleast).

https://github.com/pellejobb that project gives the same error. remove one digit from the sql on the model and it works.