Then in the second table I have select ..., null as opt from... I know that I could have an empty string with '' as opt however, I don't want an empty string, I really do need it to be null.
999999.9' union all select 999,2 and '0'='0 где купить в аптеках, Поиск и заказ лекарств в аптеках Санкт-Петербурга и Ленинградской области онлайн, бронирование и доставка лекарств.
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...
Классический вариант внедрения SQL-кода, когда в уязвимый параметр передается выражение, начинающееся с «UNION ALL SELECT». Эта техника работает, когда веб-приложения напрямую возвращают результат вывода команды SELECT на страницу...
The IS NULL operator is used to test for empty values (NULL values). The following SQL lists all customers with a NULL value in the "Address" field: Example. SELECT CustomerName, ContactName, Address FROM Customers WHERE Address IS NULL
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.
I realize this may be marked as duplicate, but I'm specifically asking in relation to SQL Server 2005 I have read conflicting advice on the internet so I'm asking here.
You can use the Oracle IS NOT NULL condition in either a SQL statement or in a block of PLSQL code.
Ken Sanchez NULL * Terri Duffy NULL * Roberto Tamburello NULL * Rob Walters NULL * Gail Erickson