private SqlProvider VisitPagingNative(UnaryProvider provider, Func <ParameterContext, int> take, Func <ParameterContext, int> skip)
{
var compiledSource = Compile(provider.Source);
var query = ExtractSqlSelect(provider, compiledSource);
var bindings = new List <QueryParameterBinding>();
if (take != null)
{
private SqlProvider VisitPagingNative(UnaryProvider provider, Func <int> take, Func <int> skip)
{
var compiledSource = Compile(provider.Source);
var query = ExtractSqlSelect(provider, compiledSource);
var bindings = new List <QueryParameterBinding>();
if (take != null)
{
// Some servers (e.g. SQL Server 2012) don't like Take(0)
// We work around it with special hacks:
// Limit argument is replaced with 1
// and false condition is added to "where" part.
var applyZeroLimitHack = providerInfo.Supports(ProviderFeatures.ZeroLimitIsError);
var takeBinding = CreateLimitOffsetParameterBinding(take, applyZeroLimitHack);
bindings.Add(takeBinding);
if (applyZeroLimitHack)
{
query.Where &= SqlDml.Variant(takeBinding, SqlDml.Literal(1), SqlDml.Literal(0)) != SqlDml.Literal(0);
}
query.Limit = takeBinding.ParameterReference;
}
if (skip != null)
{
var skipBinding = CreateLimitOffsetParameterBinding(skip);
bindings.Add(skipBinding);
query.Offset = skipBinding.ParameterReference;
}
query.OrderBy.Clear();
var columnExpressions = ExtractColumnExpressions(query);
foreach (KeyValuePair <int, Direction> pair in provider.Source.Header.Order)
{
query.OrderBy.Add(columnExpressions[pair.Key], pair.Value == Direction.Positive);
}
return(CreateProvider(query, bindings, provider, compiledSource));
}
