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 from information_schema.tables. for a small database containing three tables
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 of columns as the query it's being merged with, and shifted around
...NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,CONCAT%28version(),0x3a,user()),NULL
Этот язык специфичен, но в PHP: Null означает " ничего".
SQL NULL Functions. ❮ Previous Next ❯.
In C, a null pointer constant must be an integer literal with the value 0, or the same cast to type "pointer to void"
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.
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.
Если инструкция SELECT используется для тестирования на значения NULL в дополнение к