public override void WriteSql(SqlWriter writer, SqlVisitor visitor)
{
#region Check if FROM aliases need to be renamed
// Create a list of the aliases used by the outer extents
// JoinSymbols have to be treated specially.
List <string> outerExtentAliases = null;
if ((null != _outerExtents) && (0 < _outerExtents.Count))
{
foreach (var outerExtent in _outerExtents.Keys)
{
var joinSymbol = outerExtent as JoinSymbol;
if (joinSymbol != null)
{
foreach (var symbol in joinSymbol.FlattenedExtentList)
{
if (null == outerExtentAliases)
{
outerExtentAliases = new List <string>();
}
outerExtentAliases.Add(symbol.NewName);
}
}
else
{
if (null == outerExtentAliases)
{
outerExtentAliases = new List <string>();
}
outerExtentAliases.Add(outerExtent.NewName);
}
}
}
// An then rename each of the FromExtents we have
// If AllJoinExtents is non-null - it has precedence.
// The new name is derived from the old name - we append an increasing int.
var extentList = AllJoinExtents ?? _fromExtents;
if (null != extentList)
{
foreach (var fromAlias in extentList)
{
if ((null != outerExtentAliases) && outerExtentAliases.Contains(fromAlias.Name))
{
var i = visitor.AllExtentNames[fromAlias.Name];
string newName;
do
{
++i;
newName = fromAlias.Name + i.ToString(System.Globalization.CultureInfo.InvariantCulture);
} while (visitor.AllExtentNames.ContainsKey(newName));
visitor.AllExtentNames[fromAlias.Name] = i;
fromAlias.NewName = newName;
// Add extent to list of known names (although i is always incrementing, "prefix11" can
// eventually collide with "prefix1" when it is extended)
visitor.AllExtentNames[newName] = 0;
}
// Add the current alias to the list, so that the extents
// that follow do not collide with me.
if (null == outerExtentAliases)
{
outerExtentAliases = new List <string>();
}
outerExtentAliases.Add(fromAlias.NewName);
}
}
#endregion
// Increase the indent, so that the Sql statement is nested by one tab.
writer.Indent += 1; // ++ can be confusing in this context
writer.Write("SELECT ");
if (IsDistinct)
{
writer.Write("DISTINCT ");
}
if (Top != null)
{
Top.WriteSql(writer, visitor);
}
if ((null == Select) || Select.IsEmpty)
{
writer.Write("*");
}
else
{
Select.WriteSql(writer, visitor);
}
writer.WriteLine();
writer.Write("FROM ");
From.WriteSql(writer, visitor);
if ((null != _where) && !Where.IsEmpty)
{
writer.WriteLine();
writer.Write("WHERE ");
Where.WriteSql(writer, visitor);
}
if ((null != _groupBy) && !GroupBy.IsEmpty)
{
writer.WriteLine();
writer.Write("GROUP BY ");
GroupBy.WriteSql(writer, visitor);
}
if ((null != _orderBy) && !OrderBy.IsEmpty && (IsTopMost || Top != null))
{
writer.WriteLine();
writer.Write("ORDER BY ");
OrderBy.WriteSql(writer, visitor);
}
--writer.Indent;
}
public override void WriteSql(SqlWriter writer, SqlVisitor visitor)
{
writer.Write("TOP ");
TopCount.WriteSql(writer, visitor);
writer.Write(" ");
}
public abstract void WriteSql(SqlWriter writer, SqlVisitor visitor);
public override void WriteSql(SqlWriter writer, SqlVisitor visitor)
{
Left.WriteSql(writer, visitor);
writer.Write(GetOperator(Kind));
Right.WriteSql(writer, visitor);
}
public override void WriteSql(SqlWriter writer, SqlVisitor visitor)
{
// Symbol pair should never be part of a SqlBuilder.
Debug.Assert(false);
}