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...
11223344) UNION SELECT NULL,NULL,NULL,NULL WHERE 1=2 –- Если нет ошибки, значит синтаксис верный, т.е. используется MS SQL
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
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...
...NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,CONCAT%28version(),0x3a,user
It crashes immediately... NSInvalidArgumentException -[_NSInlineData isEqualToString:]: unrecognized selector sent to instance 0x60802d051c10 ( 0 CoreFoundation 0x00007fff921d0e7b __exceptionPreprocess + 171 1 libobjc.A.dylib 0x00007fffa...
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.
Предикат IS NULL позволяет проверить отсутствие (наличие) значения в полях таблицы. Использование в этих случаях обычных предикатов сравнения может привести к неверным результатам, так как сравнение со значением NULL дает результат UNKNOWN (неизвестно).
In this table I need to select only the ids which have both null and not null marks, and it should not be both not null or both are null in col1.
SELECT * FROM news WHERE id_news = 5. Но если злоумышленник передаст в качестве параметра id строку -1 OR 1=1 (например, так