f6233913ad
This statement (for now) outputs the name and types of the different attributes in a table. It's not standard SQL but all DBMSs that I know of implement a sort of statement for such functionality. Since the output of DESCRIBE TABLE is just a relation, an internal schema, `master` was created and a table definition for DESCRIBE into it. The table definition and the master schema are not accessible by the user.
61 lines
1.6 KiB
C++
61 lines
1.6 KiB
C++
/*
|
|
* Copyright (c) 2021, Jan de Visser <jan@de-visser.net>
|
|
* Copyright (c) 2021, Mahmoud Mandour <ma.mandourr@gmail.com>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/RefPtr.h>
|
|
#include <AK/String.h>
|
|
#include <LibCore/Object.h>
|
|
#include <LibSQL/Forward.h>
|
|
#include <LibSQL/Heap.h>
|
|
#include <LibSQL/Meta.h>
|
|
|
|
namespace SQL {
|
|
|
|
/**
|
|
* A Database object logically connects a Heap with the SQL data we want
|
|
* to store in it. It has BTree pointers for B-Trees holding the definitions
|
|
* of tables, columns, indexes, and other SQL objects.
|
|
*/
|
|
class Database : public Core::Object {
|
|
C_OBJECT(Database);
|
|
|
|
public:
|
|
~Database() override;
|
|
|
|
ErrorOr<void> open();
|
|
bool is_open() const { return m_open; }
|
|
ErrorOr<void> commit();
|
|
|
|
ErrorOr<void> add_schema(SchemaDef const&);
|
|
static Key get_schema_key(String const&);
|
|
ErrorOr<RefPtr<SchemaDef>> get_schema(String const&);
|
|
|
|
ErrorOr<void> add_table(TableDef& table);
|
|
static Key get_table_key(String const&, String const&);
|
|
ErrorOr<RefPtr<TableDef>> get_table(String const&, String const&);
|
|
|
|
ErrorOr<Vector<Row>> select_all(TableDef const&);
|
|
ErrorOr<Vector<Row>> match(TableDef const&, Key const&);
|
|
ErrorOr<void> insert(Row&);
|
|
ErrorOr<void> update(Row&);
|
|
|
|
private:
|
|
explicit Database(String);
|
|
|
|
bool m_open { false };
|
|
NonnullRefPtr<Heap> m_heap;
|
|
Serializer m_serializer;
|
|
RefPtr<BTree> m_schemas;
|
|
RefPtr<BTree> m_tables;
|
|
RefPtr<BTree> m_table_columns;
|
|
|
|
HashMap<u32, RefPtr<SchemaDef>> m_schema_cache;
|
|
HashMap<u32, RefPtr<TableDef>> m_table_cache;
|
|
};
|
|
|
|
}
|