MySQL select 函数

1，各种类型都有

2，用于获取无参数信息的有：

select PI(),RAND(),CURDATE(),CURRENT_DATE(),CURRENT_TIMESTAMP(),CURTIME(),LOCALTIME(),LOCALTIMESTAMP(),NOW(),SYSDATE(),CONNECTION_ID(),CURRENT_USER(),DATABASE(),LAST_INSERT_ID(),SESSION_USER(),SYSTEM_USER(),USER(),VERSION();

3，感兴趣的有：

select CURRENT_TIMESTAMP(),CONNECTION_ID(),CURRENT_USER(),DATABASE(),LAST_INSERT_ID(),USER(),VERSION();

4，更多信息：

show databases;

use somedatabase;

show tables from somedatabase;

show columns from somedatabase.sometable;

show index from somedatabase.sometable;

show table status from somedatabase;

5，更高级信息：

show columns from mysql.servers;

show columns from mysql.user;

show columns from mysql.db;

show columns from mysql.default_roles;

show columns from mysql.grant_roles;

show columns from mysql.password_history;

show columns from mysql.tables_priv;

6，高高级信息：

show tables from information_schema;

show columns from information_schema.tables;

select table_name,table_type,table_rows,table_comment from information_schema.tables;

show columns from information_schema.columns;

select table_name,column_name,data_type,column_key from information_schema.columns;

select TABLE_SCHEMA,table_name,column_name,data_type,column_key from information_schema.columns;

7，灵活运用

select TABLE_SCHEMA,table_name,column_name,data_type,column_key from information_schema.columns;

 select name from city into outfile '/tmp/city.xls'; -----需要运行权限-------pager cat也可尝试

8，补充：

where，where like，union，order by，group by，join

9，sql注入：所谓SQL注入，就是通过把SQL命令插入到Web表单递交或输入域名或页面请求的查询字符串，最终达到欺骗服务器执行恶意的SQL命令。