Mysql cheat sheet——Mysql使用方便查

1、选择查看一个Mysql数据库

USE database;

2、查看数据库

SHOW DATABASES;

3、查看数据库表

show tables;

4、查看数据库表的详细情况

describe table;

5、创建数据库

create database db_name;

6、创建表

create table table_name(field_name TYPE(SIZE),field2_name TYPE(SIZE));

eg:create table person(name VARCHAR(20),sex CHAR(1),birth DATE);

7、Load tab-delimited data into a table

load data local infile "infile.txt" into table table_name;

(use \n for NULL)

8、在一张表中插入一行

insert into table_name values('MyName','MyOwner','2014-07-22');

(use null for null)

9、检索信息

select from_columns from table where conditions;

ALL VALUES:select * from table;

Some values:select * from table where rec_name="value"; 

Multiple critera:select * from table where rec1="value1" and rec2="value2";

10、Reloading a new data set into existing table:

set AUTOCOMMIT=1;# used for quick recreation of table;

delete from pet;

load data local infile "infile.txt" into table table;

11、修改表中记录

update table set column_name = "new_value" where record_name="value";

12、查看表中unique记录

select distinct column_name from table;

13、排序输出

select col1,col2 from table order by col2;

(逆序)select col1,col2 from table order by col2 desc;

14、关于日期计算

select current_date,(year(current_date)-year(date_col)) as time_diff from table;MONTH(some_date) extracts the month value and DAYOFMONTH() extracts day.

15、Pattern Matching:

select * from table where rec like "blah%";

FIND 5-char values:select * from table where rec like "_____";(_is any single character)

16、Extended Regular Expression Matching正则表达式:

select * from table where rec rlike "^b$";

17、计算行数

select count(*) from table;

18、多表查询

select pet.name,comment from pet,event where pet.name=event.name;

19、查看当前选定数据库

select database();

20、自增行号

create table xxxx(number int not null auto_increment,name char(10) not null);

21、添加列到已创建的表

alter table tb1 add column[column_create syntax] after col_name; 

22、移除一列

alter table tb1 drop column col;