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...
Используйте NULL в UNION-инъекциях вместо попыток угадать строку, дату, число и прочее. Но будьте аккуратны при слепой инъекции, т.к. вы можете спутать ошибку БД и самого приложения. Некоторые языки, например ASP.NET, выдают ошибку при использовании значения NULL (т.к...
Migrating content failed because some string fields in Oracle include null characters. PostgreSQL does not allow null characters in char/text/varchar fields. e.g. when migrating the cischartingdb.institution table, the following error is...
1.3 Использование UNION + group_concat(). 1.4 Экранирование хвоста запроса. 1.5 Расщепление SQL-запроса.
0x7178627071),NULL,NULL,NULL,NULL,NULL-- FkYN ---. web server operating system: Windows 2008 or Vista web application technology: ASP.NET, PHP 5.5.10
The standard NULL can be defined as0 or 0L or ((void *) 0) or in some other way, meaning that it might be interpreted differently in such type-less contexts. An explicit cast will make sure that it is interpreted correctly as a pointer. For example, this is generally invalid (behavior is undefined).
SELECT DISTINCT product.model, pc.price FROM Product JOIN pc ON product.model = pc.model WHERE maker = 'B'
UNION — повторяющиеся строки исключаются.UNION - Excludes duplicates. Операция UNION отличается от операции JOIN :A UNION operation