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
Since a NULL concatenated with a string yields a NULL, we can attempt to build our sub-string and replace a NULL with an empty string, which is then concatenated to the next part of the name. This assumes that FirstName and Surname are always NOT NULL, but you could apply the same logic to...
SELECT m.id, m.name, m.description, m.directions, COUNT(j.markerid) as marker_jingles FROM markers AS m LEFT OUTER JOIN jingles AS j ON j.markerid=m.id WHERE 1. But am a bit stuck because I cannot figure out how to get it to return rows when the COUNT is 0.
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...
Пример: SELECT header, txt FROM news UNION ALL SELECT name, pass FROM members Это позволит объединить результаты из таблиц news
from+information_schema.tables+limit+0,1),floor(rand(0)*2)
Look at the following SELECT statement: SELECT ProductName, UnitPrice * (UnitsInStock + UnitsOnOrder) FROM Products
Viewing and COUNTing the NULLs. Sometimes we might have to do the opposite of what the default functionality does when using DISTINCT and COUNT
Существуют специальные операторы IS NULL и IS NOT NULL, которые позволяют производить сравнения с NULLами.
NULL может размещаться в поле любого типа. Тем не менее, NULL, как NULL-значение, часто используется в SQL.