protected SqlString GetSubSelectWithLimits(SqlString subquery, ICollection <IParameterSpecification> parameterSpecs, RowSelection processedRowSelection, IDictionary <string, TypedValue> parameters)
{
ISessionFactoryImplementor sessionFactory = Factory;
Dialect.Dialect dialect = sessionFactory.Dialect;
RowSelection selection = processedRowSelection;
bool useLimit = UseLimit(selection, dialect);
if (useLimit)
{
bool hasFirstRow = GetFirstRow(selection) > 0;
bool useOffset = hasFirstRow && dialect.SupportsLimitOffset;
int max = GetMaxOrLimit(dialect, selection);
int? skip = useOffset ? (int?)dialect.GetOffsetValue(GetFirstRow(selection)) : null;
int? take = max != int.MaxValue ? (int?)max : null;
Parameter skipSqlParameter = null;
Parameter takeSqlParameter = null;
if (skip.HasValue)
{
string skipParameterName = "nhsubselectskip";
var skipParameter = new NamedParameterSpecification(1, 0, skipParameterName)
{
ExpectedType = NHibernateUtil.Int32
};
skipSqlParameter = Parameter.Placeholder;
skipSqlParameter.BackTrack = skipParameter.GetIdsForBackTrack(sessionFactory).First();
parameters.Add(skipParameterName, new TypedValue(skipParameter.ExpectedType, skip.Value, EntityMode.Poco));
parameterSpecs.Add(skipParameter);
}
if (take.HasValue)
{
string takeParameterName = "nhsubselecttake";
var takeParameter = new NamedParameterSpecification(1, 0, takeParameterName)
{
ExpectedType = NHibernateUtil.Int32
};
takeSqlParameter = Parameter.Placeholder;
takeSqlParameter.BackTrack = takeParameter.GetIdsForBackTrack(sessionFactory).First();
parameters.Add(takeParameterName, new TypedValue(takeParameter.ExpectedType, take.Value, EntityMode.Poco));
parameterSpecs.Add(takeParameter);
}
// The dialect can move the given parameters where he need, what it can't do is generates new parameters loosing the BackTrack.
return(dialect.GetLimitString(subquery, skip, take, skipSqlParameter, takeSqlParameter));
}
return(subquery);
}
