Hi, all! We have received some users questions about how to send a list of values to be used in queries using the "in" operator. Something like: select foo, bar from table where foo in (blah1, blah2, blah3); Npgsql supports array-like parameter values and the first idea to have this working would try to use it directly: NpgsqlCommand command = new NpgsqlCommand("select * from tablee where field_serial in (:parameterlist)", conn); ArrayList l = new ArrayList(); l.Add(5); l.Add(6); command.Parameters.Add(new NpgsqlParameter("parameterlist", NpgsqlDbType.Array | NpgsqlDbType.Integer)); command.Parameters[0].Value = l.ToArray(); NpgsqlDataReader dr = command.ExecuteReader(); but unfortunately this won't work as expected. Npgsql will send a query like this: select * from tablee where field_serial in ((array[5,6])::int4[]) And Postgresql will complain with the followin