Union select null, null, null, null, null, null, null from information_schema.tables. for a small database containing three tables. this instruction is used in sql injection I tried it and it worked but I didn't really know how it works can somebody help me...
Union select null, null, null, null, null, null, null from information_schema.tables. for a small database containing three tables. this instruction
11223344) UNION SELECT NULL,NULL,NULL,NULL WHERE 1=2 –- Если нет ошибки, значит синтаксис верный, т.е. используется MS SQL Server.
999999.9' union all select 999,2 and '0'='0 где купить в аптеках, Поиск и заказ лекарств в аптеках Санкт-Петербурга и Ленинградской области онлайн, бронирование и доставка лекарств.
sql - Union to handle NULL values - Stack Overflow.
It is true that on most plaforms null-pointer value is represented physically by an actual zero address value. However, if on some platform address 0 is actually used for some purpose (i.e. you might need to create objects at address 0), the null-pointer value on such platform will most likely be different.
that's wrong though. (char*)NULL isn't a string at all, it's a null pointer. this isn't a string either even though it's an array of char.
MYSQL Union Based. Detect columns number.
But what exactly is NULL and how it’s defined? Strictly speaking, NULL expands to an implementation-defined null pointer constant which is defined in many header files such as
Логические операции и NULL. Обычно, состояние НЕИЗВЕСТНО обрабатывается так же, как ЛОЖЬ. Например, если вы выбираете строки из таблицы и вычисление условия x = NULL в предложении WHERE дало результат НЕИЗВЕСТНО, то вы не получите ни одной строки.