// This is without query optimization.
private static Bamboo.Query.Planning.Node NaivePlan(object query, Bamboo.Query.Database database)
{
if (query is Bamboo.Query.Query.UnionStatement)
{
Bamboo.Query.Query.UnionStatement unionStatement = (Bamboo.Query.Query.UnionStatement)query;
return(new UnionNode(NaivePlan(unionStatement.A, database), NaivePlan(unionStatement.B, database)));
}
else if (query is Bamboo.Query.Query.SelectStatement)
{
Bamboo.Query.Query.SelectStatement selectStatement = (Bamboo.Query.Query.SelectStatement)query;
System.Collections.Hashtable tables = database.Lookup(GetNames(selectStatement));
// FROM
string name = selectStatement.From;
Bamboo.Query.Planning.Node node = new Bamboo.Query.Planning.TableScanNode(name, (Bamboo.Query.Table)tables[name]);
// JOIN
foreach (Bamboo.Query.Query.JoinClause joinClause in selectStatement.Joins)
{
name = GetTableName(joinClause.RightColumn);
node = new Bamboo.Query.Planning.JoinNode(node, new Bamboo.Query.Planning.TableScanNode(name, (Bamboo.Query.Table)tables[name]), joinClause.LeftColumn, joinClause.RightColumn);
}
// WHERE
if (selectStatement.Where != null)
{
node = new Bamboo.Query.Planning.WhereNode(node, selectStatement.Where);
}
// GROUP BY
if (selectStatement.GroupBy.Count > 0)
{
node = new Bamboo.Query.Planning.GroupByNode(node, selectStatement.GroupBy, selectStatement.Select);
}
// SELECT
node = new Bamboo.Query.Planning.SelectNode(node, selectStatement.Select);
// ORDER BY
if (selectStatement.OrderBy != null)
{
node = new Bamboo.Query.Planning.OrderByNode(node, selectStatement.OrderBy);
}
return(node);
}
else
{
throw new System.Exception("Invalid query.");
}
}
public static Bamboo.Query.Table Evaluate(object query, Bamboo.Query.Database database)
{
Bamboo.Query.Table T = new Bamboo.Query.Table(GetColumns(query));
Bamboo.Query.Planning.Node plan = Bamboo.Query.Planning.Planner.Plan(query, database);
Bamboo.Query.Iterators.Iterator R = plan.CreateIterator();
R.Open();
System.Collections.IList r;
while ((r = R.GetNext()) != null)
{
T.AddRow(r);
}
R.Close();
return(T);
}
public static Bamboo.Query.Table Evaluate(string query, Bamboo.Query.Database database)
{
return(Evaluate(Bamboo.Query.Query.QueryParser.Parse(query), database));
}
public static Bamboo.Query.Planning.Node Plan(object query, Bamboo.Query.Database database)
{
return(NaivePlan(query, database));
}
