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...
UNION ALL SELECT NULL, *, NULL, NULL FROM email. I understand what this does and why; the hacker needs to create a query that has the same number
11223344) UNION SELECT NULL,NULL,NULL,NULL WHERE 1=2 –- Если нет ошибки, значит синтаксис верный, т.е. используется MS SQL
· Using SELECT COUNT(*) or SELECT COUNT(1) (which is what I prefer to use) will return the total of all records returned in the result set regardless of NULL values.
SELECT SUM(1) FROM Sales.SalesOrderDetail. Такой вариант примерно равнозначен COUNT. Мы также получим лишний Compute Scalar на
Viewing and COUNTing the NULLs. Sometimes we might have to do the opposite of what the default functionality does when using DISTINCT and COUNT
By specifically mentioning NULL pointer, C standard gives mechanism using which a C programmer can use and check whether a given pointer is legitimate or not. But what exactly is NULL and how it’s defined? Strictly speaking, NULL expands to an implementation-defined null pointer constant which is...
The first to see what might of happened here, the ‘null’ name bit, is the following command
SQL Injection Bypass WAF Techniques. 1. Null Bytes. To perform a null byte attack, you simply need to supply a URL-encoded null byte (%00) prior to the string you want bypass blocking.
Команда IS NULL проверяет поле на NULL. Пример: SELECT * FROM workers WHERE salary IS NULL.