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 ALL SELECT NULL, *, NULL, NULL FROM email. I understand what this does and why; the hacker needs to create a query that has the same number
11223344) UNION SELECT NULL,NULL,NULL,NULL WHERE 1=2 –- Если нет ошибки, значит синтаксис верный, т.е. используется MS SQL
So, I will never enter in if (x == null && y == null)? – serhio Nov 2 '10 at 12:08. point d is flat out NO, see comments. if they are pointing to a field on the object.
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.
I've been asked about counting NULL values several times so I'm going to blog about it in hopes others will be helped by this explanation of NULL values in
Команда IS NULL проверяет поле на NULL. Пример: SELECT * FROM workers WHERE salary IS NULL.
By specifically mentioning NULL pointer, C standard gives mechanism using which a C programmer can use and check whether a given pointer is legitimate or not. But what exactly is NULL and how it’s defined? Strictly speaking, NULL expands to an implementation-defined null pointer constant which is...
Подскажите, пожалуйста, что значит "NULL", и когда он применяется ? В примере ниже , насколько я понимаю, создаётся строка, и в
Разрешение значений NULL в определениях столбцов вводит в приложение логику трех значений.Allowing null values in column