private SqlFragment HandleFunction(DbFunctionAggregate fa, SqlFragment arg)
{
Debug.Assert(fa.Arguments.Count == 1);
if (fa.Function.NamespaceName != "Edm")
{
throw new NotSupportedException();
}
FunctionFragment fragment = new FunctionFragment();
fragment.Name = fa.Function.Name;
if (fa.Function.Name == "BigCount")
{
fragment.Name = "COUNT";
}
else
{
fragment.Name = fa.Function.Name.ToUpperInvariant();
}
fragment.Distinct = fa.Distinct;
fragment.Argument = arg;
return(fragment);
//return new CastExpression(aggregate, GetDbType(functionAggregate.ResultType.EdmType));
}
private SqlFragment UserDefinedFunction(DbFunctionExpression e)
{
FunctionFragment f = new FunctionFragment();
f.Name = Metadata.TryGetValueMetadataProperty <string>(e.Function,
"StoreFunctionNameAttribute");
if (String.IsNullOrEmpty(f.Name))
{
f.Name = e.Function.Name;
}
f.Quoted = !Metadata.TryGetValueMetadataProperty <bool>(e.Function, "BuiltInAttribute");
bool isFuncNiladic = Metadata.TryGetValueMetadataProperty <bool>(e.Function, "NiladicFunctionAttribute");
if (isFuncNiladic && e.Arguments.Count > 0)
{
throw new InvalidOperationException("Niladic functions cannot have parameters");
}
ListFragment list = new ListFragment();
string delimiter = "";
foreach (DbExpression arg in e.Arguments)
{
if (delimiter.Length > 0)
{
list.Append(new LiteralFragment(delimiter));
}
list.Append(arg.Accept(callingGenerator));
delimiter = ", ";
}
f.Argument = list;
return(f);
}
/// <summary>
/// If input sqlFragment is a group by structure, is flattened to remove some nested correlation queries.
/// </summary>
/// <param name="input"></param>
/// <returns></returns>
private SqlFragment TryFlatteningGroupBy(SqlFragment input)
{
SelectStatement select = null;
SelectStatement tmpFrag = null, tmpFrag2 = null, tmpFrag3 = null;
InputFragment table = null;
string objName = null, colName = null, queryName = null;
// First part assert is a kind-of structure we are looking for
tmpFrag = input as SelectStatement;
if (tmpFrag == null)
{
goto NoChanges;
}
tmpFrag = (tmpFrag).From as SelectStatement;
if (tmpFrag == null)
{
goto NoChanges;
}
queryName = tmpFrag.Name;
if (tmpFrag.Columns.Count < 2)
{
goto NoChanges;
}
if (!(tmpFrag.Columns[0] is ColumnFragment))
{
goto NoChanges;
}
colName = objName = (tmpFrag.Columns[0] as ColumnFragment).ActualColumnName;
tmpFrag2 = tmpFrag.From as SelectStatement;
if (tmpFrag2 == null)
{
goto NoChanges;
}
if (tmpFrag2.Columns.Count < 1 || !(tmpFrag2.Columns[0] is ColumnFragment))
{
goto NoChanges;
}
if (string.CompareOrdinal(objName, tmpFrag2.Columns[0].ActualColumnName) != 0)
{
goto NoChanges;
}
if (tmpFrag.Columns[1].Literal == null)
{
goto NoChanges;
}
tmpFrag2 = tmpFrag.Columns[1].Literal as SelectStatement;
if (tmpFrag2 == null)
{
goto NoChanges;
}
if ((tmpFrag2.Columns.Count != 1) || !(tmpFrag2.Columns[0].Literal != null))
{
goto NoChanges;
}
tmpFrag3 = tmpFrag2.From as SelectStatement;
if (tmpFrag3 == null)
{
goto NoChanges;
}
table = tmpFrag3.From as InputFragment;
if (table == null)
{
goto NoChanges;
}
FunctionFragment func = tmpFrag2.Columns[0].Literal as FunctionFragment;
if (tmpFrag3.Columns.Count != 1 || !(tmpFrag3.Columns[0] is ColumnFragment))
{
goto NoChanges;
}
if (func == null)
{
goto NoChanges;
}
// Yes it is the kind-of type we like, then optimize it
select = new SelectStatement(this);
table.Name = null;
string tableName = null;
TableFragment t = tmpFrag3.From as TableFragment;
if (t == null)
{
tableName = tmpFrag3.Columns[0].TableName;
}
else
{
tableName = t.Table;
}
select.From = table;
select.Columns.Add(new ColumnFragment(tableName, colName));
select.Columns.Add(new ColumnFragment(tableName, "C0")
{
ColumnAlias = "C1",
Literal = new FunctionFragment()
{
Argument = new ColumnFragment(tableName, tmpFrag3.Columns[0].ActualColumnName),
Distinct = tmpFrag3.IsDistinct,
Name = func.Name
}
});
select.Wrap(null);
select.Name = queryName;
select.AddGroupBy(select.Columns[0]);
(input as SelectStatement).From = select;
NoChanges:
return(input);
}
public void Visit(FunctionFragment f)
{
}