Sybase及SQL Anywhere SQL语句小结

  WHERE sales_order.sales_rep = employee.emp_id

SELECT E.emp_lname, S.id, S.order_date

  FROM sales_order as S, employee as E

  WHERE S.sales_rep = E.emp_id

  ORDER BY E.emp_lname

连接两表的快捷键：KEY JOIN及NATURAL JOIN，最好用WHERE.

SELECT emp_lname, id, order_date

  FROM sales_order

  KEY JOIN employee

(主键与外部键对应的地方，就可以用KEY JOIN)

SELECT company_name,

  CAST( SUM(sales_order_items.quantity * product.unit_price) AS INTEGER) AS value

  FROM customer

  KEY JOIN sales_order