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...
It should be noted that NULL pointer is different from an uninitialized and dangling pointer. In a specific program context, all uninitialized or dangling or NULL pointers are invalid but
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.
IS NULL вернёт истину, если операнд имеет значение NULL и ложь, если он им не является.
999999.9+union+all+select+%27R3DM0V3_hvj_injection',null
Note: A NULL value is different from a zero value or a field that contains spaces. A field with a NULL value is one that has been left blank during record creation!
5.5 How should NULL be defined on a machine which uses a nonzero bit pattern as the internal representation
null-null-null-null-. 22,408 post karma 7,798 comment karma. send a private messageredditor for 1 year.
NULL в Системах управления базами данных (СУБД) — специальное значение (псевдозначение), которое может быть записано в поле таблицы базы данных (БД). NULL соответствует понятию «пустое поле», то есть «поле, не содержащее никакого значения».
Значение NULL в реляционной базе данных используется, если значение в столбце неизвестно или отсутствует.A null value in a relational database is