sql - CONCAT'ing NULL fields - Stack Overflow
Now, if I do: SELECT CONCAT(FirstName, LastName, Email) as Vitals FROM MEMBERS.
SQL using If Not Null on a Concatenation - Stack Overflow
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...
sql - Counting null values as unique value - Stack Overflow
Hours 1 1 2 null null null. The result must be: 3. My query is: select count(distinct hour) from hours; but it returns: 2. I tested also
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...
The SQL Injection Knowledge Base | Find Columns from Table Name
SELECT CONCAT_WS(0x3A, user, password) FROM mysql.user WHERE user = 'root'-- (Privileged).
Шпаргалка по SQL инъекциям | DefconRU
(M): SELECT CONCAT(login, password) FROM members. 7. Строки без кавычек Есть несколько способов не использовать кавычки в запросе, например с помощью CHAR() (MS) и CONCAT() (M). Синтаксис: SELECT 0x457578 (M). В MySQL есть простой способ представления строки в...
COUNT(*) / Хабр
SELECT FirstName, COUNT(*) FROM Person.Person GROUP BY FirstName. Посмотрел на план запроса и увидел там явно неадекватное значение Estimated number of rows: Заглянул в статистику по кластерному индексу
SQL Count not null values in every table column - Softhints
Count by single select query. Oracle count null and not null values for several columns. If you need to check the number of null values per column for tables with many columns or for many tables you can use meta database meta information. In most databases there is technical and statistical information.
SQL NULL Values - IS NULL and IS NOT NULL
SELECT column_names FROM table_name WHERE column_name IS NOT NULL; Demo Database.
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...