public override SqlFragment Visit(DbSortExpression expression)
{
SelectStatement select = VisitInputExpressionEnsureSelect(expression.Input.Expression,
expression.Input.VariableName, expression.Input.VariableType);
select = WrapIfNotCompatible(select, expression.ExpressionKind);
foreach (DbSortClause sortClause in expression.SortOrder)
{
select.AddOrderBy(new SortFragment(
sortClause.Expression.Accept(this), sortClause.Ascending));
}
return(select);
}
public override SqlFragment Visit(DbSkipExpression expression)
{
SelectStatement select = VisitInputExpressionEnsureSelect(expression.Input.Expression, expression.Input.VariableName,
expression.Input.VariableType);
select = WrapIfNotCompatible(select, DbExpressionKind.Sort);
foreach (DbSortClause sortClause in expression.SortOrder)
{
select.AddOrderBy(
new SortFragment(sortClause.Expression.Accept(this), sortClause.Ascending));
}
// if we wrapped above, then this wrap will not create a new one so there
// is no harm in calling it
select = WrapIfNotCompatible(select, expression.ExpressionKind);
select.Skip = expression.Count.Accept(this);
return(select);
}
protected internal SelectStatement FuseSelectWithInnerSelect(SelectStatement outer, SelectStatement inner)
{
string oldTableName = (inner.From as TableFragment).Name;
string newTableName = inner.Name;
Dictionary <string, ColumnFragment> dicColumns = new Dictionary <string, ColumnFragment>();
foreach (ColumnFragment cf in inner.Columns)
{
if (cf.ColumnAlias != null)
{
dicColumns.Add(cf.ColumnAlias, cf);
}
}
outer.From = inner.From;
(outer.From as TableFragment).Name = newTableName;
// Dispatch Where
if (outer.Where == null)
{
outer.Where = inner.Where;
}
else if (inner.Where != null)
{
outer.Where = new BinaryFragment()
{
Left = outer.Where, Right = inner.Where, Operator = "AND"
};
}
VisitAndReplaceTableName(outer.Where, oldTableName, newTableName, dicColumns);
// For the next constructions, either is defined on outer or at inner, not both
// Dispatch Limit
if (outer.Limit == null)
{
outer.Limit = inner.Limit;
VisitAndReplaceTableName(outer.Limit, oldTableName, newTableName, dicColumns);
}
// Dispatch GroupBy
if (outer.GroupBy == null && inner.GroupBy != null)
{
foreach (SqlFragment sf in inner.GroupBy)
{
outer.AddGroupBy(sf);
}
foreach (SqlFragment sf in outer.GroupBy)
{
VisitAndReplaceTableName(sf, oldTableName, newTableName, dicColumns);
}
}
// Dispatch OrderBy
if (outer.OrderBy != null || inner.OrderBy != null)
{
if (inner.OrderBy != null)
{
foreach (SortFragment sf in inner.OrderBy)
{
outer.AddOrderBy(sf);
}
}
foreach (SortFragment sf in outer.OrderBy)
{
VisitAndReplaceTableName(sf, oldTableName, newTableName, dicColumns);
}
}
// Dispatch Skip
if (outer.Skip == null)
{
outer.Skip = inner.Skip;
}
return(outer);
}
