select a,b,null,null from table1 union select null,null,c,d from table2 union select null,null,null,null,e,f from table3.
Note: A NULL value is different from a zero value or a field that contains spaces.
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...
Use NULL in UNION injections for most data type instead of trying to guess string, date, integer etc. Be careful in Blind situtaions may you can understand error is coming from DB or
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.
If I have this - tadd is the Address table: … Is there a way to exclude the apt_number if it doesn't exist? I was thinking of: … But it will return only those rows with apt_number...
...option=com_ncatalogues&controller=ajax&task=multiselect&id=28%20UNION%20ALL
The IS NOT NULL condition is used in SQL to test for a non-NULL value. It returns TRUE if a non-NULL value is found, otherwise it returns FALSE. It can be used in a SELECT
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).
1 UNION ALL SELECT NULL,concat(0x28,column1,0x3a,column2,0x29) FROM database2.table1--. Error Based.