Home php教程 php手册 Mysql数据库学习心得(4)

Mysql数据库学习心得(4)

Jun 21, 2016 am 09:02 AM
auction gt mysql

 

 10.表的数据更新

  (1)一次修改一个字段,再次注意语法。文本需要加引号但数字不要。

   mysql>update table01 set field03='new info'swheresfield01=1;

   Query OK, 1 row affected (0.00 sec)

  (2)一次改变多个字段,记住在每一个更新的字段间用逗号隔开。

   mysql>update table01 set field04=19991022, field05=062218swheresfield01=1;

   Query OK, 1 row affected (0.00 sec)

  (3)一次更新多个数据

   mysql>update table01 set field05=152901swheresfield04>19990101;

   Query OK, 3 rows affected (0.00 sec)

  11.删除数据

   mysql>delete from table01swheresfield01=3;

   Query OK, 1 row affected (0.00 sec)

  12.导入数据库表

   (1)创建.sql文件

   (2)先产生一个库如auction.c:mysqlin>mysqladmin -u root -p creat auction,会提示输入密码,然后成功创建。

   (3)导入auction.sql文件

    c:mysqlin>mysql -u root -p auction auction.sql

   通过以上操作,就可以创建了一个数据库auction以及其中的一个表auction。

  13.mysql数据库的授权

   mysql>grant select,insert,delete,create,drop

   on *.* (或test.*/user.*/..)

   to用户名@localhost

   identified by '密码';

  如:新建一个用户帐号以便可以访问数据库,需要进行如下操作:

   mysql> grant usage

   -> ON test.*

   -> TO testuser@localhost;

   Query OK, 0 rows affected (0.15 sec)

  此后就创建了一个新用户叫:testuser,这个用户只能从localhost连接到数据库并可以连接到test数据库。下一步,我们必须指定     testuser这个用户可以执行哪些操作:

   mysql> GRANT select, insert, delete,update

   -> ON test.*

   -> TO testuser@localhost;

   Query OK, 0 rows affected (0.00 sec)

  此操作使testuser能够在每一个test数据库中的表执行SELECT,INSERT和DELETE以及UPDATE查询操作。现在我们结束操作并退出MySQL客户  程序:

   mysql> exit

   Bye

  14.授权MySQL用户密码

  MySQL数据库的默认用户名为"root"(MS SQL Server的sa相似),密码默认为空。在DOS提示符(注意,不是mysql提示符)下输入

  c:mysqlin>"mysqladmin -u root -p password newpassword

  回车后会提示你输入原来的密码,由于原来密码为空,直接回车,root用户的密码便改为"newpassword"了。

 



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