二、数据库操作SQL语句 1、显示服务器上当前存在什么数据库 SHOW DATABASES;2、创建名称为rewin的数据库 CREATE DATABASE rewin; 3、删除名称为rewin的数据库 DROP DATABASE rewin; 4、选择rewin数据库 USE rewin; 三、表操作SQL语句(登录之后必须用以上的USE命令选择一个数据库,再进行表操作) 1、显示当前数据库中存在什么表 SHOW TABLES;
2、创建数据库表zhangyan:在mysql>后粘贴以下SQL语句,存储引擎为MYISAM,字段id为主键、唯一索引。 CREATE TABLE `zhangyan` ( `id` INT( 5 ) UNSIGNED NOT NULL AUTO_INCREMENT , `username` VARCHAR( 20 ) NOT NULL , `password` CHAR( 32 ) NOT NULL , `time` DATETIME NOT NULL , `number` FLOAT( 10 ) NOT NULL , `content` TEXT NOT NULL , PRIMARY KEY ( `id` ) ) ENGINE = MYISAM ; 3、查看zhangyan表结构 DESCRIBE zhangyan; 4、从表中检索信息 4.1、从zhangyan表中检索所有记录 SELECT * FROM zhangyan; 4.2、从zhangyan表中检索特定的行:字段username等于abc,字段number等于1,按字段id降序排列 SELECT * FROM zhangyan WHERE username = 'abc' AND number='1' ORDER BY id DESC; 4.3、从zhangyan表中检索指定的字段:username和password SELECT username, password FROM zhangyan; 4.4、从zhangyan表中检索出唯一的不重复记录: SELECT DISTINCT username FROM zhangyan; 5、插入信息到zhangyan表 INSERT INTO zhangyan (id, username, password, time, number, content) VALUES ('', 'abc', '123456', '2007-08-06 14:32:12', '23.41', 'hello world'); 6、更新zhangyan表中的指定信息 UPDATE zhangyan SET content = 'hello china' WHERE username = 'abc'; 7、删除zhangyan表中的指定信息 DELETE FROM zhangyan WHERE id = 1; 8、清空zhangyan表 DELETE FROM zhangyan; 9、删除zhangyan表 DROP TABLE zhangyan; 10、更改表结构,将zhangyan表username字段的字段类型改为CHAR(25) ALTER TABLE zhangyan CHANGE username username CHAR(25); 11、将当前目录下的mysql.sql导入数据库 SOURCE ./mysql.sql; 四、数据库权限操作SQL语句 1、创建一个具有root权限,可从任何IP登录的用户sina,密码为zhangyan GRANT ALL PRIVILEGES ON *.* TO 'sina'@'%' IDENTIFIED BY 'zhangyan' WITH GRANT OPTION; FLUSH PRIVILEGES;
2、创建一个具有“数据操作”、“结构操作”权限,只能从192.168.1.***登录的用户sina,密码为zhangyan GRANT SELECT , INSERT , UPDATE , DELETE , FILE , CREATE , DROP , INDEX , ALTER , CREATE TEMPORARY TABLES , CREATE VIEW , SHOW VIEW , CREATE ROUTINE, ALTER ROUTINE, EXECUTE ON *.* TO 'sina'@'192.168.1.%' IDENTIFIED BY 'zhangyan'; 3、创建一个只拥有“数据操作”权限,只能从192.168.1.24登录,只能操作rewin数据库的zhangyan表的用户sina,密码为zhangyan GRANT SELECT , INSERT , UPDATE , DELETE ON rewin.zhangyan TO 'sina'@'192.168.1.24' IDENTIFIED BY 'zhangyan'; 4、创建一个拥有“数据操作”、“结构操作”权限,可从任何IP登录,只能操作rewin数据库的用户sina,密码为zhangyan GRANT SELECT , INSERT , UPDATE , DELETE , CREATE , DROP , INDEX , ALTER , CREATE TEMPORARY TABLES , CREATE VIEW , SHOW VIEW , CREATE ROUTINE, ALTER ROUTINE, EXECUTE ON rewin.* TO 'sina'@'%' IDENTIFIED BY 'zhangyan'; 5、删除用户 DROP USER 'sina'@'%'; |