count query in sql database

SELECT COUNT(column_name)

FROM table_name

WHERE condition; 

  SELECT Orders.OrderID, Customers.CustomerName, Shippers.ShipperName
FROM 
  ((Orders
INNER JOIN Customers ON Orders.CustomerID = Customers.CustomerID)

  INNER JOIN Shippers ON Orders.ShipperID = Shippers.ShipperID); 

SELECT column1, column2, ...

FROM table_name

ORDER BY column1, column2, ... ASC|DESC; 

 SELECT * FROM Customers

 ORDER BY Country;
 

SELECT AVG(column_name)

FROM table_name

WHERE condition; 

SELECT SUM(column_name)

FROM table_name

WHERE condition;