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...
However, this will return NULL provider results as well, how would I exclude all null results?
...NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULl, NULL-- Можно использовать CAST
Best Result For : 999999.9 uNiOn aLl sElEcT cAsT 0x393133353134353632312e39 as char --. تفسير فرط السبحة في المنام.
If a null pointer constant is converted to a pointer type, the resulting pointer, called a null pointer, ... which covers (int *)0 as null pointer since cast is an
If a null pointer constant is converted to a pointer type, the resulting pointer, called a null pointer, is guaranteed to compare unequal to a pointer to any object or function.”
I think your nitpicking is incorrect: (char*)NULL is a null pointer, but "\0" is an empty string. "" is also an empty string, as is "\0abc".
Добрый день! Подскажите, пожалуйста, что значит "NULL", и когда он применяется ? В примере ниже , насколько я понимаю, создаётся строка, и в этой
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.
A field with a NULL value is a field with no value. If a field in a table is optional, it is possible to insert a new record or update a record without adding a value to this field.