mysql常用操作语句

时间:2022-06-06 23:41:50

mysql常用操作语句

1.mysql -u root -p   2.mysql -h localhost -u root -p database_name

2.列出数据库:

1.show databases;

3.选择数据库:

1.use databases_name;

4.列出数据表:

1.show tables;

5.显示表格列的属性:

1.show columns from table_name;   2.describe table_name;

6.导出整个数据库:

1.mysqldump -u user_name -p database_name > /tmp/file_name

例如:mysqldump -u root -p test_db > d:/test_db.sql

7.导出一个表:

1.mysqldump -u user_name -p database_name table_name > /tmp/file_name

例如:mysqldump -u root -p test_db table1 > d:/table1.sql

8.导出一个数据库结构:

1.mysqldump -u user_name -p -d --add-drop-table database_name > file_name

例如:mysqldump -u root -p -d --add-drop-table test_db > test_db.sql

9.导入数据库:

1.source file_name;   2.或   3.mysql -u user_name -p database_name < file_name

例如:

source /tmp/bbs.sql;

source d:/bbs.sql;

mysql -u root -p bbs < "d:/bbs.sql"

mysql -u root -p bbs < "/tmp/bbs.sql"

10.将文本文件导入数据表中(excel与之相同)

1.load data infile "tables.txt" into table table_name;

例如:

load data infile "/tmp/bbs.txt" into table bbs;

load data infile "/tmp/bbs.xls" into table bbs;

load data infile "d:/bbs.txt" into table bbs;

load data infile "d:/bbs.xls" into table bbs;

11.将数据表导出为文本文件(excel与之相同)

1.select * into outfile "path_file_name" from table_name;

例如:

select * into outfile "/tmp/bbs.txt" from bbs;

select * into outfile "/tmp/bbs.xls" from bbs where id=1;

select * into outfile "d:/bbs.txt" from bbs;

select * into outfile "d:/bbs.xls" from bbs where id=1;

12.创建数据库时先判断数据库是否存在:

1.create database if not exists database_name;

例如:create database if not exists bbs

13.创建数据库:

1.create database database_name;

例如:create database bbs;

14.删除数据库:

1.drop database database_name;

例如:drop database bbs;

15.创建数据表:

1.mysql> create table <table_name> ( <column 1 name> <col. 1 type> <col. 1 details>,<column 2 name> <col. 2 type> <col. 2 details>, ...);

例如:create table (id int not null auto_increment primary key,name char(16) not null default "jack",date_year date not null);

16.删除数据表中数据:

1.delete from table_name;

例如:

delete from bbs;

delete from bbs where id=2;

17.删除数据库中的数据表:

1.drop table table_name;

例如:

drop table test_db;

rm -f database_name/table_name.* (linux下)

例如:

rm -rf bbs/accp.*

18.向数据库中添加数据:

1.insert into table_name set column_name1=value1,column_name2=value2;

例如:insert into bbs set name="jack",date_year="1993-10-01";

1.insert into table_name values (column1,column2,...);

例如:insert into bbs ("2","jack","1993-10-02")

1.insert into table_name (column_name1,column_name2,...) values (value1,value2);

例如:insert into bbs (name,data_year) values ("jack","1993-10-01");

19.查询数据表中的数据:

1.select * from table_name;

例如:select * from bbs where id=1;

20.修改数据表中的数据:

1.update table_name set col_name=new_value where id=1;

例如:update bbs set name="tom" where name="jack";

21.增加一个字段:

1.alter table table_name add column field_name datatype not null default "1";

例如:alter table bbs add column tel char(16) not null;

22.增加多个字段:(column可省略不写)

1.alter table table_name add column filed_name1 datatype,add column filed_name2 datatype;

例如:alter table bbs add column tel char(16) not null,add column address text;

23.删除一个字段:

1.alter table table_name drop field_name;

例如:alter table bbs drop tel;

24.修改字段的数据类型:

1.alter table table_name modify id int unsigned;//修改列id的类型为int unsigned    2.alter table table_name change id sid int unsigned;//修改列id的名字为sid,而且把属性修改为int unsigned

25.修改一个字段的默认值:

1.alter table table_name modify column_name datatype not null default "";

例如:alter table test_db modify name char(16) default not null "yourname";

26.对表重新命名:

1.alter table table_name rename as new_table_name;

例如:alter table bbs rename as bbs_table;

1.rename table old_table_name to new_table_name;

例如:rename table test_db to accp;

27.从已经有的表中复制表的结构:

1.create table table2 select * from table1 where 1<>1;

例如:create table test_db select * from accp where 1<>1;

28.查询时间:

1.select now();

29.查询当前用户:

1.select user();

30.查询数据库版本:

1.select version();

31.创建索引:

1.alter table table1 add index ind_id(id);   2.create index ind_id on table1(id);   3.create unique index ind_id on table1(id);//建立唯一性索引

32.删除索引:

1.drop index idx_id on table1;   2.alter table table1 drop index ind_id;

33.联合字符或者多个列(将id与":"和列name和"="连接)

1.select concat(id,':',name,'=') from table;

34.limit(选出10到20条)

1.select * from bbs order by id limit 9,10;

(从查询结果中列出第几到几条的记录)

35.增加一个管理员账号:

1.grant all on *.* to user@localhost identified by "password";

36.创建表是先判断表是否存在

1.create table if not exists students(……);

37.复制表:

1.create table table2 select * from table1;

例如:create table test_db select * from accp;

38.授于用户远程访问mysql的权限

1.grant all privileges on *.* to "root"@"%" identified by "password" with grant option;

或者是修改mysql数据库中的user表中的host字段

1.use mysql;   2.select user,host from user;   3.update user set host="%" where user="user_name";

39.查看当前状态

1.show status;

40.查看当前连接的用户

1.show processlist;

(如果是root用户,则查看全部的线程,得到的用户连接数同show status;里的 Threads_connected值是相同的)