(2)外部結合クエリ
(3)複合条件接続クエリ
mysql ビデオ チュートリアル )
mysql> create table suppliers -> ( -> s_id int not null auto_increment, -> s_name char(50) not null, -> s_city char(50) null, -> s_zip char(10) null, -> s_call char(50) not null, -> primary key(s_id) -> );Query OK, 0 rows affected (0.17 sec)mysql> insert into suppliers(s_id,s_name,s_city,s_zip,s_call) -> values(101,'FastFruit Inc.','Tianjin','300000','48075'), -> (102,'LT Supplies','Chongqing','400000','44333'), -> (103,'ACME','Shanghai','200000','90046'), -> (104,'FNK Inc.','Zhongshan','528437','11111'), -> (105,'Good Set','Taiyuan','030000','22222'), -> (106,'Just Eat Ours','Beijing','010','45678'), -> (107,'DK Inc','Zhengzhou','450000','33332');Query OK, 7 rows affected (0.07 sec)Records: 7 Duplicates: 0 Warnings: 0
[例 1] 果物テーブルとサプライヤー テーブルの間で内部結合クエリを使用します。
mysql> desc fruits;+---------+--------------+------+-----+---------+-------+| Field | Type | Null | Key | Default | Extra |+---------+--------------+------+-----+---------+-------+| f_id | char(10) | NO | PRI | NULL | || s_id | int(11) | NO | | NULL | || f_name | char(255) | NO | | NULL | || f_price | decimal(8,2) | NO | | NULL | |+---------+--------------+------+-----+---------+-------+4 rows in set (0.06 sec)mysql> desc suppliers;+--------+----------+------+-----+---------+----------------+| Field | Type | Null | Key | Default | Extra |+--------+----------+------+-----+---------+----------------+| s_id | int(11) | NO | PRI | NULL | auto_increment || s_name | char(50) | NO | | NULL | || s_city | char(50) | YES | | NULL | || s_zip | char(10) | YES | | NULL | || s_call | char(50) | NO | | NULL | |+--------+----------+------+-----+---------+----------------+5 rows in set (0.00 sec)
果物テーブルとサプライヤー テーブルの両方に同じデータ型フィールド s_id があり、2 つのテーブルが s_id フィールドを通じて接続されていることがわかります。
次に、fruits テーブルから f_name フィールドと f_price フィールドをクエリし、suppliers テーブルから s_id と s_name をクエリします。SQL ステートメントは次のとおりです:
mysql> select suppliers.s_id,s_name,f_name,f_price -> from fruits,suppliers -> where fruits.s_id=suppliers.s_id;+------+----------------+------------+---------+| s_id | s_name | f_name | f_price |+------+----------------+------------+---------+| 104 | FNK Inc. | lemon | 6.40 || 101 | FastFruit Inc. | apple | 5.20 || 103 | ACME | apricot | 2.20 || 101 | FastFruit Inc. | blackberry | 10.20 || 104 | FNK Inc. | berry | 7.60 || 107 | DK Inc | xxxx | 3.60 || 102 | LT Supplies | orange | 11.20 || 105 | Good Set | melon | 8.20 || 101 | FastFruit Inc. | cherry | 3.20 || 106 | Just Eat Ours | mango | 15.70 || 105 | Good Set | xbabay | 2.60 || 105 | Good Set | xxtt | 11.60 || 103 | ACME | coconut | 9.20 || 102 | LT Supplies | banana | 10.30 || 102 | LT Supplies | grape | 5.30 || 107 | DK Inc | xbabay | 3.60 |+------+----------------+------------+---------+16 rows in set (0.00 sec)
mysql> select suppliers.s_id,s_name,f_name,f_price -> from fruits inner join suppliers -> on fruits.s_id = suppliers.s_id;+------+----------------+------------+---------+| s_id | s_name | f_name | f_price |+------+----------------+------------+---------+| 104 | FNK Inc. | lemon | 6.40 || 101 | FastFruit Inc. | apple | 5.20 || 103 | ACME | apricot | 2.20 || 101 | FastFruit Inc. | blackberry | 10.20 || 104 | FNK Inc. | berry | 7.60 || 107 | DK Inc | xxxx | 3.60 || 102 | LT Supplies | orange | 11.20 || 105 | Good Set | melon | 8.20 || 101 | FastFruit Inc. | cherry | 3.20 || 106 | Just Eat Ours | mango | 15.70 || 105 | Good Set | xbabay | 2.60 || 105 | Good Set | xxtt | 11.60 || 103 | ACME | coconut | 9.20 || 102 | LT Supplies | banana | 10.30 || 102 | LT Supplies | grape | 5.30 || 107 | DK Inc | xbabay | 3.60 |+------+----------------+------------+---------+16 rows in set (0.00 sec)
[例 3]
f_id='a1' を供給する果物供給業者が提供する果物の種類をクエリする場合、SQL ステートメントは次のとおりです。 <div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false">mysql> select f1.f_id,f1.f_name -> from fruits as f1,fruits as f2 -> where f1.s_id =f2.s_id and f2.f_id ='a1';+------+------------+| f_id | f_name |+------+------------+| a1 | apple || b1 | blackberry || c0 | cherry |+------+------------+3 rows in set (0.00 sec)</pre><div class="contentsignin">ログイン後にコピー</div></div>
1. 左結合
最初にテーブルの順序を作成します。SQL ステートメントは次のとおりです。
mysql> create table orders -> ( -> o_num int not null auto_increment, -> o_date datetime not null, -> c_id int not null, -> primary key (o_num) -> );Query OK, 0 rows affected (0.11 sec)mysql> insert into orders(o_num,o_date,c_id) -> values(30001,'2008-09-01',10001), -> (30002,'2008-09-12',10003), -> (30003,'2008-09-30',10004), -> (30004,'2008-10-03',10005), -> (30005,'2008-10-08',10001);Query OK, 5 rows affected (0.06 sec)Records: 5 Duplicates: 0 Warnings: 0
[例] 顧客の場合table とorders table の場合、注文のない顧客を含むすべての顧客をクエリする場合、SQL ステートメントは次のとおりです:
mysql> select * from customers;+-------+----------+---------------------+---------+--------+-----------+-------------------+| c_id | c_name | c_address | c_city | c_zip | c_contact | c_email |+-------+----------+---------------------+---------+--------+-----------+-------------------+| 10001 | redhool | 200 Street | Tianjin | 300000 | LiMing | LMing@163.com || 10002 | Stars | 333 Fromage Lane | Dalian | 116000 | Zhangbo | Jerry@hotmail.com || 10003 | Netbhood | 1 Sunny Place | Qingdao | 266000 | LuoCong | NULL || 10004 | JOTO | 829 Riverside Drive | Haikou | 570000 | YangShan | sam@hotmail.com |+-------+----------+---------------------+---------+--------+-----------+-------------------+4 rows in set (0.00 sec)mysql> select * from orders;+-------+---------------------+-------+| o_num | o_date | c_id |+-------+---------------------+-------+| 30001 | 2008-09-01 00:00:00 | 10001 || 30002 | 2008-09-12 00:00:00 | 10003 || 30003 | 2008-09-30 00:00:00 | 10004 || 30004 | 2008-10-03 00:00:00 | 10005 || 30005 | 2008-10-08 00:00:00 | 10001 |+-------+---------------------+-------+5 rows in set (0.00 sec)mysql> select customers.c_id , orders.o_num -> from customers left outer join orders -> on customers.c_id = orders.c_id;+-------+-------+| c_id | o_num |+-------+-------+| 10001 | 30001 || 10003 | 30002 || 10004 | 30003 || 10001 | 30005 || 10002 | NULL |+-------+-------+5 rows in set (0.00 sec)
2. Right join
right joinmysql> select customers.c_id, orders.o_num -> from customers right outer join orders -> on customers.c_id = orders.c_id;+-------+-------+| c_id | o_num |+-------+-------+| 10001 | 30001 || 10003 | 30002 || 10004 | 30003 || NULL | 30004 || 10001 | 30005 |+-------+-------+5 rows in set (0.00 sec)
mysql> select customers.c_id,orders.o_num -> from customers inner join orders -> on customers.c_id = orders.c_id and customers.c_id = 10001;+-------+-------+| c_id | o_num |+-------+-------+| 10001 | 30001 || 10001 | 30005 |+-------+-------+2 rows in set (0.00 sec)
[ 例 2] 果物テーブルとサプライヤー テーブルの間で、内部結合構文を使用して内部結合クエリを実行し、クエリ結果を並べ替えます。SQL ステートメントは次のとおりです:
mysql> select suppliers.s_id,s_name,f_name,f_price -> from fruits inner join suppliers -> on fruits.s_id = suppliers.s_id -> order by fruits.s_id;+------+----------------+------------+---------+| s_id | s_name | f_name | f_price |+------+----------------+------------+---------+| 101 | FastFruit Inc. | apple | 5.20 || 101 | FastFruit Inc. | blackberry | 10.20 || 101 | FastFruit Inc. | cherry | 3.20 || 102 | LT Supplies | orange | 11.20 || 102 | LT Supplies | banana | 10.30 || 102 | LT Supplies | grape | 5.30 || 103 | ACME | apricot | 2.20 || 103 | ACME | coconut | 9.20 || 104 | FNK Inc. | lemon | 6.40 || 104 | FNK Inc. | berry | 7.60 || 105 | Good Set | melon | 8.20 || 105 | Good Set | xbabay | 2.60 || 105 | Good Set | xxtt | 11.60 || 106 | Just Eat Ours | mango | 15.70 || 107 | DK Inc | xxxx | 3.60 || 107 | DK Inc | xbabay | 3.60 |+------+----------------+------------+---------+16 rows in set (0.00 sec)
その他の関連する無料学習の推奨事項 :mysql チュートリアル(ビデオ)
以上がMySQL データクエリ接続クエリの詳細内容です。詳細については、PHP 中国語 Web サイトの他の関連記事を参照してください。
![[Web フロントエンド] Node.js クイック スタート](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
