Статья - SQL-injection, начало - UNION BASED - Codeby.net

sql injection "union select null" - CodeProject

Union select null, null, null, null, null, null, null from information_schema.tables. for a small database containing three tables. When you do a UNION query, both SELECT statements of the query must have the same number of columns.

SQL Injection Union Based Exploitation : Part 2 The Injection

Advanced SQL Injection: Union based | VK9 Security

How to select null when the record does not exist with UNION ALL?

SQL Injection | Hacking Walkthroughs

SQL-инъекции' union select null, null, null -- / Хабр

?id=1' union select null,null,table_name,null from information_schema.tables Это стало возможным благодаря добавлению таблицы information_schema в MySQL 5.0+ и по ее наличию также можно косвенно определить версию используемой БД.

How the SQL UNION Operator Deals with NULL Values

The SQL UNION operator concatenates the results of two queries into a single result set. We can use the ALL keyword to include all duplicates, and that includes duplicate NULLs: Select null union all select null union all select null

SQL Injection Using UNION

1 UNION SELECT 1 FROM information_schema.tables. The first step is to gather information about the database schema by crafting a valid SELECT statement.

SQL Injection/UNION Attack - charlesreid1