// drop statement
private void HandleStatement(DropStatement statement)
{
_catalogManager.CheckValidation(statement);
SchemaRecord schema;
switch (statement.TargetType)
{
case DropTarget.Table:
schema = _catalogManager.GetTableSchemaRecord(statement.TableName);
List <SchemaRecord> indices = _catalogManager.GetIndicesSchemaRecord(statement.TableName);
// drop table
_catalogManager.DropStatement(statement);
_recordManager.DropTable(schema.RootPage);
// drop index trees
foreach (SchemaRecord index in indices)
{
_recordManager.DropTable(index.RootPage);
}
break;
case DropTarget.Index:
schema = _catalogManager.GetIndexSchemaRecord(statement.IndexName);
_catalogManager.DropStatement(statement);
_recordManager.DropTable(schema.RootPage);
break;
}
}
//check whether we can successfully return the schema record of a table or an index
static bool CheckGetSchemaRecord()
{
SchemaRecord target_table = icatalog.GetTableSchemaRecord("Student");
Console.WriteLine("Schema of Table");
Console.WriteLine(target_table.Name);
Console.WriteLine(target_table.RootPage);
Console.WriteLine(target_table.Type);
Console.WriteLine(target_table.SQL.PrimaryKey);
Console.WriteLine(target_table.SQL.TableName);
Console.WriteLine(target_table.SQL.Type);
SchemaRecord target_index = icatalog.GetIndexSchemaRecord("index_for_student_id");
Console.WriteLine("Schema of Index");
Console.WriteLine(target_index.Name);
Console.WriteLine(target_index.RootPage);
Console.WriteLine(target_index.Type);
Console.WriteLine(target_index.SQL.IndexName);
Console.WriteLine(target_index.SQL.IsUnique);
Console.WriteLine(target_index.SQL.Type);
List <SchemaRecord> target_indices = icatalog.GetIndicesSchemaRecord("Student");
for (int i = 0; i < target_indices.Count; i++)
{
Console.WriteLine("Schema of Indices");
Console.WriteLine(target_indices[i].Name);
Console.WriteLine(target_indices[i].RootPage);
Console.WriteLine(target_indices[i].Type);
Console.WriteLine(target_indices[i].SQL.IndexName);
Console.WriteLine(target_indices[i].SQL.IsUnique);
Console.WriteLine(target_indices[i].SQL.Type);
}
return(true);
}