SQL, как с выражением
SELECT CONCAT(first_name, ' ', last_name) AS full_name
FROM Customers;
SAMER SAEID
SELECT CONCAT(first_name, ' ', last_name) AS full_name
FROM Customers;WITH temporaryTable (averageValue) as
(SELECT avg(Attr1)
FROM Table)
SELECT Attr1
FROM Table, temporaryTable
WHERE Table.Attr1 > temporaryTable.averageValue;