static bool CheckUpdate()
{
//update the rootpage of a table
SchemaRecord table_before = icatalog.GetTableSchemaRecord("Student");
Console.WriteLine(table_before.RootPage);
icatalog.TryUpdateSchemaRecord("Student", 2);
SchemaRecord table_after = icatalog.GetTableSchemaRecord("Student");
Console.WriteLine(table_after.RootPage);
Debug.Assert(table_after.RootPage == 2);
//update the rootpage of an index
SchemaRecord index_before = icatalog.GetIndexSchemaRecord("index_for_student_id");
Console.WriteLine(index_before.RootPage);
icatalog.TryUpdateSchemaRecord("index_for_student_id", 3);
SchemaRecord index_after = icatalog.GetIndexSchemaRecord("index_for_student_id");
Console.WriteLine(index_after.RootPage);
Debug.Assert(index_after.RootPage == 3);
//try to update the table or index that does not exist
//will print false
bool test1 = icatalog.TryUpdateSchemaRecord("HHH", 5);
bool test2 = icatalog.TryUpdateSchemaRecord("hhh", 6);
Console.WriteLine(test1);
Console.WriteLine(test2);
Debug.Assert(test1 == false);
Debug.Assert(test2 == false);
return(true);
}
// delete statement
// NOTICE: relative index trees will NOT change accordingly
private void HandleStatement(DeleteStatement statement)
{
// get table and indices
_catalogManager.CheckValidation(statement);
SchemaRecord tableSchema = _catalogManager.GetTableSchemaRecord(statement.TableName);
List <SchemaRecord> indexSchemas = _catalogManager.GetIndicesSchemaRecord(statement.TableName);
// TODO
// delete index records from index trees
// __problem__:
// attribute names := (priKey, a, b, c)
// condition := b < 3 and c > 5
// fun facts: b and c both have index trees
// issue: to delete the records satisfying the condition above
// delete record from table tree
int newTableRootPage = _recordManager.DeleteRecords(statement.Condition, tableSchema.SQL.PrimaryKey, tableSchema.SQL.AttributeDeclarations, tableSchema.RootPage);
_catalogManager.TryUpdateSchemaRecord(statement.TableName, newTableRootPage);
}
