[nhibernate-development] Bug found in DriverBase.RemoveUnusedCommandParameters

[Mike Charalambous]

Hi

I have recently written a NHibernate driver for the Sybase Advantage
Database Server (ADS), and have across a bug in the function
RemoveUnusedCommandParameters when running queries with parameters in
them. This bug means that all parameters are removed by
RemoveUnusedCommandParameters instead of just the ones which are
unused. Please see the bottom of my post for the driver code.

The heart of the issue is that ADS requires a prefix to be used when
referring to parameters in SQL, but not when the parameter is in the
parameter collection. The RemoveUnusedCommandParameters function does
not take into account that the parameter name can have a prefix in the
SQL and not in the parameter collection and so removes all parameters
from the command object.

I think the fix for this issue is straightforward and as far as I can
tell will not cause any issues with existing drivers. The code:

 .Select(p => p.ParameterName)

should be changed to:

.Select(p => FormatNameForSql(p.ParameterName))


I have created a unit test for this issue but it requires binaries for
the Advantage Database Server. Is this okay?

Thanks

Mike Charalambous

  public class SybaseAdsClientDriver :
NHibernate.Driver.ReflectionBasedDriver
    {
        public SybaseAdsClientDriver()
            : base("Advantage.Data.Provider",
                   "Advantage.Data.Provider.AdsConnection",
                   "Advantage.Data.Provider.AdsCommand")
        {
        }

        public override bool UseNamedPrefixInSql
        {            get { return true; }        }

        public override bool UseNamedPrefixInParameter
        {            get { return false; }        }

        public override string NamedPrefix
        {            get { return ":"; }        }
    }