protected virtual Expression VisitSelect(SelectExpression select)
{
var project = (LambdaExpression)this.Visit(select.Projection);
var from = (FromExpression)this.Visit(select.From);
var where = (WhereExpression)this.Visit(select.Where);
var take = this.Visit(select.Take);
var orderBy = this.VisitOrderBy(select.OrderBy);
if (project == select.Projection &&
from == select.From &&
where == select.Where &&
take == select.Take &&
orderBy == select.OrderBy)
return select;
return CompleteExpression.Select(select.Alias, project, from, orderBy, where, select.IsProjection);
}
protected override Expression VisitSelect(SelectExpression select)
{
return select;
}
protected virtual Expression VisitSelect(SelectExpression select)
{
this.Write(".Select(");
this.WriteLine(Indentation.Inner);
this.Write(".Project(");
this.WriteLine(Indentation.Inner);
this.Visit(select.Projection);
this.WriteLine(Indentation.Outer);
this.Write("),");
this.WriteLine(Indentation.Same);
this.Visit(select.From);
if (select.Where != null)
{
this.Write(",");
this.WriteLine(Indentation.Same);
this.Visit(select.Where);
this.WriteLine(Indentation.Outer);
}
this.Write(") as ");
this.Write(select.Alias);
return select;
}
protected override Expression VisitSelect(SelectExpression select)
{
var topLevel = isTopLevel;
isTopLevel = false;
sb.Append("select ");
if (select.Take != null)
{
sb.Append("top (");
this.Visit(select.Take);
sb.Append(") ");
}
var add_comma = false;
foreach (var c in select.Columns)
{
if (add_comma)
sb.Append(", ");
else
add_comma = true;
this.Visit(c.Declaration);
sb.AppendFormat(" as [{0}]", c.Name);
}
this.AppendNewLine(Indentation.Same);
sb.Append("from ");
this.Visit(select.From);
this.Visit(select.Where);
// can only write order by if top level or if take != null
if (topLevel || select.Take != null)
// can only write order by if order by is not null
if (select.OrderBy != null)
{
if (select.OrderBy.SortColumns.Count == 0 && select.OrderBy.SecondarySortingClause == null)
throw new InvalidOperationException("How did we end up here?");
sb.Append("order by ");
this.VisitOrderBy(select.OrderBy);
}
return select;
}
private IEnumerable<Expression> GetDistinctColumns(SelectExpression select, Expression expression)
{
fromExpressions.Push(select.From);
var columns = GetDistinctColumns(expression);
fromExpressions.Pop();
return columns;
}
private OrderByClause BuildNestedOrderBy(SelectExpression select, OrderByClause orderBy)
{
if (orderBy == null)
return null;
var newOrderBy = new OrderByClause(BuildNestedOrderBy(select, orderBy.SecondarySortingClause));
var columns = orderBy.SortColumns;
var unmatchedColumns = new List<Expression>();
foreach (var col in columns)
{
Expression expr = select.TryFindColumn(col.Item1);
if (expr == null)
expr = select.AddUnmappedColumn(col.Item1);
newOrderBy.AppendColumn(Tuple.Create(expr, col.Item2));
}
return newOrderBy;
}
private OrderByClause BuildNestedOrderBy(SelectExpression select)
{
return BuildNestedOrderBy(select, select.OrderBy);
}
private SelectExpression BuildNestedSelect(SelectExpression select)
{
var orderBy = BuildNestedOrderBy(select);
var from = CompleteExpression.From(select);
var projection = ColumnReplacer.ReplaceColumns(select.Projection) as LambdaExpression;
select = CompleteExpression.Select(
GetNextAlias(),
projection,
from,
orderBy,
isProjection: false);
return select;
}
