private static string[] GetNames(Bamboo.Query.Query.SelectStatement selectStatement)
{
string[] names = new string[1 + selectStatement.Joins.Count];
names[0] = selectStatement.From;
System.Collections.IList joins = selectStatement.Joins;
for (int i = 0; i < joins.Count; i++)
{
names[i + 1] = GetTableName(((Bamboo.Query.Query.JoinClause)joins[i]).RightColumn);
}
return(names);
}
// 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.");
}
}
private static System.Collections.ICollection GetColumns(object query)
{
if (query is Bamboo.Query.Query.UnionStatement)
{
Bamboo.Query.Query.UnionStatement unionStatement = (Bamboo.Query.Query.UnionStatement)query;
return(GetColumns(unionStatement.A));
}
else if (query is Bamboo.Query.Query.SelectStatement)
{
Bamboo.Query.Query.SelectStatement selectStatement = (Bamboo.Query.Query.SelectStatement)query;
System.Collections.ArrayList columns = new System.Collections.ArrayList(selectStatement.Select.Count);
foreach (Bamboo.Query.Query.Column column in selectStatement.Select)
{
columns.Add(GetColumnName(column));
}
return(columns);
}
else
{
throw new System.Exception("Invalid query.");
}
}
