This query

var q = from trxd2 in metaData.TransactionsD select new { trxd2.Balance, XX = (trxd2.Balance ?? 0m) < 0m ? Math.Abs(trxd2.Balance ?? 0m) : 0m, }; var result = q.ToList();

throw an exception that ** "The parameter at position 1 is of an unsupported type: Call " **

I tried to call Math.Abs(trxd2.Balance ?? 0m) alone, it works fine

any help ??

using 2.6 Adapter mode for sql file version 2.6.10.517 latest version

Math.Abs isn't mapped. You have to create your own Custom Function Mapping.

mohamed wrote:

This query

var q = from trxd2 in metaData.TransactionsD select new { trxd2.Balance, XX = Math.Abs(trxd2.Balance ?? 0m) }; var result = q.ToList();

I tried to call Math.Abs(trxd2.Balance ?? 0m) alone, it works fine

why it didn't work under condition ??

That second query: the Math.Abs() is a call to an in-memory method, and compiled in the projection, the first query: it is embedded in a CASE statement, and therefore requires a mapping.

Walaa wrote:

That second query: the Math.Abs() is a call to an in-memory method, and compiled in the projection, the first query: it is embedded in a CASE statement, and therefore requires a mapping.

Thank you Walaa. Could you please Inform me with details how is the linq provider conceder to call in memory or converted to SQL statement.

It depends on whether the framework can find a function mapped to this method or not. If not it will be considered an in-memory method.

Default supported methods