mysql>CREATETABLEtestalter_tbl ->( ->iINT, ->cCHAR(1) ->); Query OK,0ROWSaffected(0.05sec) mysql>SHOWCOLUMNSFROMtestalter_tbl; +---+---+---+---+---+---+ |FIELD|TYPE|NULL|KEY|DEFAULT|Extra| +---+---+---+---+---+---+ |i|INT(11)|YES||NULL|| |c|CHAR(1)|YE...
mysql>ALTERTABLEtestalter_tblENGINE=MYISAM;mysql>SHOWTABLESTATUSLIKE'testalter_tbl'\G***1.row***Name:testalter_tblType:MyISAMRow_format:FixedRows:0Avg_row_length:0Data_length:0Max_data_length:25769803775Index_length:1024Data_free:0Auto_increment:NULLCreate_time:2007-06-03 08:04:36Update_tim...
10 rows in set (0.01 sec) mysql> update gz_phone set phone=’11111111111′ where id=1001; Query OK, 0 rows affected (2 min 57.88 sec) Rows matched: 1 Changed: 0 Warnings: 0 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 说明当...
ALTER TABLE操作を実行します。 この例では、employees サンプルデータベースの employees テーブルにmiddle_nameカラムが追加されます。 mysql>ALTERTABLEemployees.employeesADDCOLUMNmiddle_namevarchar(14)AFTERfirst_name;Query OK, 0 rows affected (9.27 sec)Records: 0 Duplicates: 0 Warnings: 0...
mysql>updatehuanqiu.hahasetname="wangshikui"whereid=11; Query OK, 1 row affected (0.00 sec) Rowsmatched: 1 Changed: 1 Warnings: 0 mysql>select*fromhuanqiu.haha; +---+---+ | id |name| +---+---+ | 1 | wangshibo | | 11 |...
mysql> lock table actor read; Query OK, 0 rows affected (0.00 sec) 1. 2. (2)但是通过别名访问会提示错误: AI检测代码解析 mysql> select a.first_name,a.last_name,b.first_name,b.last_name from actor a,actor b where a.first_name = b.first_name and a.first_name = 'Lisa' and a....
employees ADD COLUMN middle_name varchar(14) AFTER first_name; Query OK, 0 rows affected (9.27 sec) Records: 0 Duplicates: 0 Warnings: 0 进度查询 代码语言:javascript 代码运行次数:0 运行 AI代码解释 mysql> SELECT EVENT_NAME, WORK_COMPLETED, WORK_ESTIMATED FROM performance_schema.events_stages_...
MySQL 8.0.29 开始,ALTER TABLE … ALGORITHM=INSTANT 支持删除某列。如下先添加两列,再删除两列: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 mysql>ALTERTABLEsbtest1ADDCOLUMNc4int(10),ADDCOLUMNc5int(10),ALGORITHM=INSTANT;QueryOK,0rows affected,2warnings(0.10sec)Records:0Duplicates:0Warnings:2...
1 row in set (0.00 sec)mysql> ALTER DATABASE db_test2 COLLATE ‘utf8_unicode_520_ci’; #输入语句，修改数据库排序规则。Query OK, 1 row affected, 1 warning (0.03 sec)mysql> SHOW CREATE DATABASE db_test2;+———-+———-+| Database | Create Database |+———-+———-+| db...
mysql> ALTER DATABASE character_set3 DEFAULT CHARSET=utf16le COLLATE utf16le_bin;Query OK, 1 row affected (0.00 sec)这条语句与修改数据表语句非常接近，语句格式也雷同。有命令语句：ALTER DATABASE；之后指定需要修改的数据库名称：character_set3；DEFAULT CHARSET=XXXX来指定需要自改的字符集名称。这个...