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mysql常用操作语句
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)
mysql常用操作语句