SQL using If Not Null on a Concatenation - Stack Overflow
As @Prdp noted, the answer is RDBMS-specific. What is specific is whether the server treats a zero-length string as being equivalent to NULL, which determines whether concatenating a NULL yields a NULL or not. Generally COALESCE is most concise for PostgreSQL-style empty string handling, and...
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. 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...
oracle - What is the difference between select count(*) and select...
COUNT(*) will include NULLS. COUNT(column_or_expression) won't. This means COUNT(any_non_null_column) will give the same as COUNT(*) of course because there are no NULL values to cause differences. Generally, COUNT(*) should be better because any index can be used...
SQL COUNT « Язык запросов SQL
Синтаксис функции COUNT: SELECT COUNT(expression) FROM table WHERE predicates; Функция COUNT принимает один из нескольких параметров
The SQL Injection Knowledge Base | Find Columns from Table Name
SELECT CONCAT_WS(0x3A, user, password) FROM mysql.user WHERE user = 'root'-- (Privileged).
Ask TOM "Getting multiple counts with a union"
select (select count(*) from tablea)+(select count(*) from tableb) from dual. Not saying it's better (I can't test it right now so it might not even work!)
Шпаргалка по SQL инъекциям | DefconRU
(M): SELECT CONCAT(login, password) FROM members. 7. Строки без кавычек Есть несколько
25 примеров команды SELECT в MySQL | ИТ Блог.
Если вы используете базу данных MySQL, это очень важно, чтобы вы работали комфортно с командной строкой MySQL. На этом уроке мы расскажем, как использовать команду SELECT в MySQL с несколькими...
SQL SELECT DISTINCT Statement
The SELECT DISTINCT statement is used to return only distinct (different) values.