protected override Expression VisitSelect(SelectExpression select)
{
select = (SelectExpression)base.VisitSelect(select);
if (select.Skip != null)
{
Expression expression3;
SelectExpression sel = select.SetSkip(null).SetTake(null);
if (select.IsDistinct || ((select.GroupBy != null) && (select.GroupBy.Count != 0)))
{
sel = sel.AddRedundantSelect(this.language, new TableAlias());
}
QueryType columnType = this.language.TypeSystem.GetColumnType(typeof(int));
sel = sel.AddColumn(new ColumnDeclaration("row__num", new RowNumberExpression(select.OrderBy), columnType)).AddRedundantSelect(this.language, new TableAlias());
sel = sel.RemoveColumn(sel.Columns.Single <ColumnDeclaration>(c => c.Name == "row__num"));
TableAlias alias = ((SelectExpression)sel.From).Alias;
ColumnExpression expression = new ColumnExpression(typeof(int), columnType, alias, "row__num");
if (select.Take != null)
{
expression3 = new BetweenExpression(expression, Expression.Add(select.Skip, Expression.Constant(1)), Expression.Add(select.Skip, select.Take));
}
else
{
expression3 = expression.GreaterThan(select.Skip);
}
if (sel.Where != null)
{
expression3 = sel.Where.And(expression3);
}
select = sel.SetWhere(expression3);
}
return(select);
}
public virtual ProjectionExpression AddOuterJoinTest(ProjectionExpression proj)
{
QueryType columnType;
Expression outerJoinTest = this.GetOuterJoinTest(proj.Select);
SelectExpression select = proj.Select;
ColumnExpression test = null;
foreach (ColumnDeclaration declaration in select.Columns)
{
if (outerJoinTest.Equals(declaration.Expression))
{
columnType = this.TypeSystem.GetColumnType(outerJoinTest.Type);
test = new ColumnExpression(outerJoinTest.Type, columnType, select.Alias, declaration.Name);
break;
}
}
if (test == null)
{
test = outerJoinTest as ColumnExpression;
string baseName = (test != null) ? test.Name : "Test";
baseName = proj.Select.Columns.GetAvailableColumnName(baseName);
columnType = this.TypeSystem.GetColumnType(outerJoinTest.Type);
select = select.AddColumn(new ColumnDeclaration(baseName, outerJoinTest, columnType));
test = new ColumnExpression(outerJoinTest.Type, columnType, select.Alias, baseName);
}
return(new ProjectionExpression(select, new OuterJoinedExpression(test, proj.Projector), proj.Aggregator));
}