private SqlSelectStatement CreateNewSelectStatement(SqlSelectStatement oldStatement, string inputVarName, TypeUsage inputVarType, bool finalizeOldStatement, out Symbol fromSymbol)
{
fromSymbol = null;
if (finalizeOldStatement && oldStatement.Select.IsEmpty)
{
var columns = AddDefaultColumns(oldStatement);
var oldJoinSymbol = oldStatement.FromExtents[0] as JoinSymbol;
if (oldJoinSymbol != null)
{
var newJoinSymbol = new JoinSymbol(inputVarName, inputVarType, oldJoinSymbol.ExtentList);
newJoinSymbol.IsNestedJoin = true;
newJoinSymbol.ColumnList = columns;
newJoinSymbol.FlattenedExtentList = oldJoinSymbol.FlattenedExtentList;
fromSymbol = newJoinSymbol;
}
}
if (fromSymbol == null)
{
fromSymbol = new Symbol(inputVarName, inputVarType, oldStatement.OutputColumns, oldStatement.OutputColumnsRenamed);
}
var selectStatement = new SqlSelectStatement();
selectStatement.From.Append("( ");
selectStatement.From.Append(oldStatement);
selectStatement.From.AppendLine();
selectStatement.From.Append(") ");
return(selectStatement);
}
private SqlSelectStatement VisitInputExpression(Predicate inputPredicate, string inputVarName, TypeUsage inputVarType, out Symbol fromSymbol)
{
SqlSelectStatement result;
var sqlFragment = inputPredicate.Accept(this);
result = sqlFragment as SqlSelectStatement;
if (result == null)
{
result = new SqlSelectStatement();
WrapNonQueryExtent(result, sqlFragment, inputPredicate.PredicateType);
}
if (result.FromExtents.Count == 0)
{
fromSymbol = new Symbol(inputVarName, inputVarType);
}
else if (result.FromExtents.Count == 1)
{
fromSymbol = result.FromExtents[0];
}
else
{
var joinSymbol = new JoinSymbol(inputVarName, inputVarType, result.FromExtents);
joinSymbol.FlattenedExtentList = result.AllJoinExtents;
fromSymbol = joinSymbol;
result.FromExtents.Clear();
result.FromExtents.Add(fromSymbol);
}
return(result);
}