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...
Best Result For : 999999.9 uNiOn aLl sElEcT cAsT 0x393133353134353632312e39 as char
The Background I was trying to solve the fourth realistic mission in hackthissite.org, and couldn't figure out exactly what SQL I should inject into the URL to retrieve the list of emails.
PLAY161 » 2 results for: 999999 9 30000UNION all select null null null null null null select concat 0X7E 0X27 0X723.
Note: A NULL value is different from a zero value or a field that contains spaces.
In general, every NULL value is taken into account to vary from each alternative NULL in the database.
i am trying to do union i get data with null values and i want do not want it to show in result. such as: column1 col2 col3 col4 col5 col6 test1 1 2 3 null 6 test2 2
Тем не менее, NULL, как NULL-значение, часто используется в SQL. Предположим, появился покупатель, которому еще не назначен продавец.
In computer programming, a null-terminated string is a character string stored as an array containing the characters and terminated with a null character ('\0', called NUL in ASCII). Alternative names are C string, which refers to the C programming language and ASCIIZ...
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».