Linux Memo/MySQL文法のバックアップソース(No.3)

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Linux Memo/MySQL文法へ行く。
- 1 (2008-10-02 (木) 08:03:55)
- 2 (2008-10-02 (木) 08:18:56)
- 3 (2008-10-07 (火) 07:06:28)
- 4 (2008-10-13 (月) 07:21:45)
- 5 (2008-10-13 (月) 10:50:54)
- 6 (2008-10-13 (月) 11:11:29)
- 7 (2008-10-14 (火) 00:28:52)
- 8 (2008-11-13 (木) 13:03:09)
- 9 (2009-06-08 (月) 06:23:02)
*MySQL文法 [#i8c60410]

RIGHT:更新日&lastmod();

**テーブル名の変更・複製 [#y94408d0]

''テーブル名の変更''

ALTER TABLE 古いテーブル名 RENAME 新しいテーブル名;

 mysql> ALTER TABLE ism_test RENAME ism_test2;
 Query OK, 0 rows affected (0.00 sec)

''テーブルの複製''

create table 新しいテーブル名 as select * from 元のテーブル名;

 mysql> create table ism_test as select * from ism_test2;
 Query OK, 1 row affected (0.03 sec)
 Records: 1  Duplicates: 0  Warnings: 0

必要なレコードだけ残しコピーすることも可

create table 新しいテーブル名 as select * from 元のテーブル名 where (条件);

**Select文いろいろ [#a4c33429]

''入れ子表現''

入れ子は()で囲む

テーブルism_shouhinのすべてのIDフィールドの値と等しい、テーブルism_uriageのIDフィールドを抽出

 mysql> select * from ism_uriage where ID in (select ID from ism_shouhin);
 +----+---------------------------+------+-----------+-----------+------+
 | ID | date                      | uid  | shouhinid | uriagesuu | etc  |
 +----+---------------------------+------+-----------+-----------+------+
 |  1 | 2008/09/27 (Sat) 23:41:05 | 3    |        14 |         2 | NULL |
 |  2 | 2008/09/27 (Sat) 23:41:05 | 3    |        16 |         4 | NULL |
 |  3 | 2008/09/27 (Sat) 23:41:05 | 3    |        18 |         6 | NULL |
 |  5 | 2008/09/27 (Sat) 23:45:02 | 3    |        11 |         1 | NULL |
 
 (略) 
 
 | 33 | 2008/09/28 (Sun) 01:48:04 | 2    |        16 |         4 | NULL |
 | 34 | 2008/09/28 (Sun) 01:50:02 | 2    |        20 |         2 | NULL |
 | 35 | 2008/09/28 (Sun) 01:50:35 | 2    |        23 |         2 | NULL |
 +----+---------------------------+------+-----------+-----------+------+
 32 rows in set (0.01 sec)


''フィールドの合計を別名で表示''

 mysql> select uid, uriagesuu, uid+uriagesuu as sum from ism_uriage where shouhinid=9;
 +------+-----------+------+
 | uid  | uriagesuu | sum  |
 +------+-----------+------+
 | 3    |         2 |    5 |
 | 2    |         2 |    4 |
 | 2    |         4 |    6 |


''フィールドの文字の連結''

 mysql> select uid, uriagesuu, concat(uid, uriagesuu) as gousei from ism_uriage where shouhinid=9;
 +------+-----------+--------+
 | uid  | uriagesuu | gousei |
 +------+-----------+--------+
 | 3    |         2 | 32     |
 | 2    |         2 | 22     |
 | 2    |         4 | 24     |


''数値比較して結果を表示''

 mysql> select uid, uriagesuu, strcmp(uid, uriagesuu) as hikaku from ism_uriage where shouhinid=9;
 +------+-----------+--------+
 | uid  | uriagesuu | hikaku |
 +------+-----------+--------+
 | 3    |         2 |      1 |
 | 2    |         2 |      0 |
 | 2    |         4 |     -1 |
 | 2    |         4 |     -1 |
 | 2    |         4 |     -1 |



''select in''

 mysql> select * from ism_shouhin where ID in (10,12,15);
 +------+---------------+------+--------+------+----------+------+
 | ID   | name          | grp  | kakaku | url  | status   | etc  |
 +------+---------------+------+--------+------+----------+------+
 |   10 | ビール 500ml  | 201  |    360 |      |          |      |
 |   12 | 発泡酒 500ml  | 201  |    164 |      |          |      |
 |   15 | ワイン (ロゼ) | 201  |    680 |      | 販売終了 |      |
 +------+---------------+------+--------+------+----------+------+
 3 rows in set (0.00 sec)

否定形 [not in]

 mysql> select * from ism_shouhin where ID not in (10,12,15);
 +------+-------------------+------+--------+-----------------+------
 | ID   | name              | grp  | kakaku | url | status    | etc  |
 +------+-------------------+------+--------+-----+-----------+------
 |    9 | ビール 350ml      | 201  |    250 |     |           |      |
 |   11 | 発泡酒 350ml      | 201  |    134 |     |           |      |
 |   13 | 焼酎 (芋)         | 201  |   1048 |     |           |      |
 |   14 | 焼酎 (麦)         | 201  |   1148 |     |           |      |
 |   16 | ワイン (白)       | 201  |    650 |     |           |      |
 +------+-------------------+------+--------+-----+-----------+-------

***テーブル名の一時変更 [#rc32bbe6]

 mysql> select ID,name as 名前,kakaku as 単価 from ism_shouhin where ID in(10,12,15);
 +------+---------------+------+
 | ID   | 名前          | 単価 |
 +------+---------------+------+
 |   10 | ビール 500ml  |  360 |
 |   12 | 発泡酒 500ml  |  164 |
 |   15 | ワイン (ロゼ) |  680 |
 +------+---------------+------+
 3 rows in set (0.00 sec)

***テーブル結合 [#c3927a8d]

 select ism_uriage.* , ism_shouhin.* from ism_uriage join ism_shouhin on  
 ism_uriage.shouhinid=ism_shouhin.ID where ism_uriage.uid=2 order  by
 ism_uriage.ID desc limit 3;
 +-----+---------------------------+------+-----------+-----------+------+------+
 ----------------------------+------+--------+-----------------------------------
 --------------------------------------------+--------+------+
 | ID  | date                      | uid  | shouhinid | uriagesuu | etc  | ID    |
  name                       | grp  | kakaku | url    | status | etc  |
 +-----+---------------------------+------+-----------+-----------+------+------+

 ----------------------------+------+--------+-----------------------------------
 --------------------------------------------+--------+------+
 | 160 | 2008/10/02 (Thu) 15:52:20 | 2    |         1 |         1 | NULL |    1 |
  冷蔵庫 AB-12345（H)        | 101  |  45000 |        |        |      |
 | 159 | 2008/10/02 (Thu) 15:52:20 | 2    |        18 |         4 | NULL |   18 |
  カクテルバー(レモン)       | 201  |    121 |        |        |      |
 | 158 | 2008/10/02 (Thu) 15:52:20 | 2    |        21 |         2 | NULL |   21 |
  コンパクトカメラ(Leica C2) | 301  |  37590 |        |        |      |
 +-----+---------------------------+------+-----------+-----------+------+------+
 ----------------------------+------+--------+-----------------------------------
 --------------------------------------------+--------+------+
 
 3 rows in set (0.01 sec)

***テーブル作成・削除時のテーブル存在の確認 [#f0e44c4d]

 mysql> DROP TABLE IF EXISTS ism_test;
 Query OK, 0 rows affected, 1 warning (0.00 sec)



 mysql> create table if not exists ism_test( ID int8, date  varchar(64), etc  varchar(64));
 Query OK, 0 rows affected (0.02 sec)


***フィールド名および型の変更 [#k3a975c5]

''型の変更''(data)

 mysql> show fields from ism_test;
 +-------+-------------+------+-----+---------+-------+
 | Field | Type        | Null | Key | Default | Extra |
 +-------+-------------+------+-----+---------+-------+
 | ID    | bigint(20)  | YES  |     | NULL    |       |
 | date  | varchar(64) | YES  |     | NULL    |       |
 | etc   | varchar(64) | YES  |     | NULL    |       |
 +-------+-------------+------+-----+---------+-------+
 3 rows in set (0.01 sec)

 mysql> alter table ism_test change date date int8;
 Query OK, 0 rows affected (0.01 sec)
 Records: 0  Duplicates: 0  Warnings: 0

 mysql> show fields from ism_test;
 +-------+-------------+------+-----+---------+-------+
 | Field | Type        | Null | Key | Default | Extra |
 +-------+-------------+------+-----+---------+-------+
 | ID    | bigint(20)  | YES  |     | NULL    |       |
 | date  | bigint(20)  | YES  |     | NULL    |       |
 | etc   | varchar(64) | YES  |     | NULL    |       |
 +-------+-------------+------+-----+---------+-------+
 3 rows in set (0.01 sec)

''名前の変更''(data)

 mysql> alter table ism_test change date data varchar(64);
 Query OK, 0 rows affected (0.01 sec)
 Records: 0  Duplicates: 0  Warnings: 0

 mysql> show fields from ism_test;
 +-------+-------------+------+-----+---------+-------+
 | Field | Type        | Null | Key | Default | Extra |
 +-------+-------------+------+-----+---------+-------+
 | ID    | bigint(20)  | YES  |     | NULL    |       |
 | data  | varchar(64) | YES  |     | NULL    |       |
 | etc   | varchar(64) | YES  |     | NULL    |       |
 +-------+-------------+------+-----+---------+-------+
 3 rows in set (0.00 sec)


''書式形式''~

 alter table <テーブル名> change <フィールド名> <新フィールド名>　<型> 


***入力されるデータの範囲越えのとき [#ae1c5409]

MySQLでは、定義さている値より多い値を入れようとすると、許容範囲まで入る。

''dataが4Byte''

 mysql> show fields from ism_test;
 +-------+-------------+------+-----+---------+-------+
 | Field | Type        | Null | Key | Default | Extra |
 +-------+-------------+------+-----+---------+-------+
 | ID    | int(11)     | YES  |     | NULL    |       |
 | data  | varchar(4)  | YES  |     | NULL    |       |
 | etc   | varchar(64) | YES  |     | NULL    |       |
 +-------+-------------+------+-----+---------+-------+
 3 rows in set (0.00 sec)

''dataに5byte入力してみると4Byteまで入る''

 mysql> insert into ism_test values(1,'12345','岡田');
 Query OK, 1 row affected, 1 warning (0.00 sec)

 mysql> select * from ism_test;
 +------+------+------+
 | ID   | data | etc  |
 +------+------+------+
 |    1 | 1234 | 岡田 |
 +------+------+------+
 1 row in set (0.00 sec)

&color(red){フィールドの型を変更すると矛盾すると値がなくなる （varchar=>int型に変更した場合)};

 mysql> select * from ism_test;
 +------+------+------+
 | ID   | data | etc  |
 +------+------+------+
 |    1 | 1234 | 岡田 |
 +------+------+------+
 1 row in set (0.00 sec)

 mysql> alter table ism_test change etc etc int4;
 Query OK, 1 row affected, 1 warning (0.00 sec)
 Records: 1  Duplicates: 0  Warnings: 1

 mysql> select * from ism_test;
 +------+------+------+
 | ID   | data | etc  |
 +------+------+------+
 |    1 | 1234 |    0 |
 +------+------+------+
 1 row in set (0.00 sec)

***フィールドの追加・削除 [#h116c978]

''追加''

 mysql> show fields from ism_test;
 +-------+------------+------+-----+---------+-------+
 | Field | Type       | Null | Key | Default | Extra |
 +-------+------------+------+-----+---------+-------+
 | ID    | int(11)    | YES  |     | NULL    |       |
 | data  | bigint(20) | YES  |     | NULL    |       |
 | etc   | int(11)    | YES  |     | NULL    |       |
 +-------+------------+------+-----+---------+-------+
 3 rows in set (0.00 sec)

 mysql> ALTER table ism_test add etc2 varchar(64);
 Query OK, 1 row affected (0.01 sec)
 Records: 1  Duplicates: 0  Warnings: 0

 mysql> show fields from ism_test;
 +-------+-------------+------+-----+---------+-------+
 | Field | Type        | Null | Key | Default | Extra |
 +-------+-------------+------+-----+---------+-------+
 | ID    | int(11)     | YES  |     | NULL    |       |
 | data  | bigint(20)  | YES  |     | NULL    |       |
 | etc   | int(11)     | YES  |     | NULL    |       |
 | etc2  | varchar(64) | YES  |     | NULL    |       |
 +-------+-------------+------+-----+---------+-------+
 4 rows in set (0.00 sec)

''削除''

 mysql> ALTER table ism_test drop etc2;
 Query OK, 1 row affected (0.01 sec)
 Records: 1  Duplicates: 0  Warnings: 0
Linux Memo/MySQL文法 のバックアップソース(No.3)

Linux Memo/MySQL文法のバックアップソース(No.3)
