Dapper trying to parse wrong column

[v0l]

Run into a small issue with dapper trying to map the previous column to the wrong field in the class and as such is throwing "Specified cast is not valid".

   at Dapper.SqlMapper.ThrowDataException(Exception ex, Int32 index, IDataReader reader, Object value)
   at Deserialize04ea767d-0f4a-4b86-ab84-f46ff296e65f(IDataReader )
   at Dapper.SqlMapper.<QueryImpl>d__125`1.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Dapper.SqlMapper.Query[T](IDbConnection cnn, String sql, Object param, IDbTransaction transaction, Boolean buffered, Nullable`1 commandTimeout, Nullable`1 commandType)

Inner exception

     at Oracle.ManagedDataAccess.Client.OracleDataReader.GetDecimal(Int32 i)
   at Oracle.ManagedDataAccess.Client.OracleDataReader.GetValue(Int32 i)
   at Oracle.ManagedDataAccess.Client.OracleDataReader.get_Item(Int32 i)
   at Deserialize04ea767d-0f4a-4b86-ab84-f46ff296e65f(IDataReader )

Nuget package version s

<package id="Oracle.ManagedDataAccess" version="12.1.24160419" targetFramework="net45" />
<package id="Dapper" version="1.50.2" targetFramework="net45" />

[v0l]

After some digging this appears to be an issue with OracleDataReader.

Its attempting to parse NUMBER as decimal but the max precision is 28-29?

This error message with "PRICE=L" is just an incorrect error. It was attempting to parse the correct column.

create table test2 ( test NUMBER );
insert into test2 values(0.36363636363636363636363636363636363636);
commit;
--Try the select * from test2; this will fail

update test2 set test = 0.3636363636363636363636363636;
commit;
--this one will work fine

[NickCraver]

Since this is really an Oracle problem, I'm not sure there's anything we can do about the root exception here, unfortunately. If the error message is off in the current version, that certainly needs a fix though.

[NickCraver]

Any update here?

[cottsak]

I think this is rather Microsoft's implementation that's at fault: always trying to cast to a Decimal, when sometimes that won't work.

I'm going to try and truncate the value in the Oracle query before it gets to the Oracle.ManagedDataAccess package.