oracle MINUS INTERSECT UNION ALL

INTERSECT示例 以下语句将结果与INTERSECT运算符组合，该运算符仅返回由两个查询返回的唯一行：

SELECT product_id FROM inventorys 
INTERSECT 
SELECT product_id FROM order_items 
ORDER BY product_id;

MINUS示例 以下语句将结果与MINUS运算符相结合，该运算符仅返回由第一个查询返回但不是第二个查询返回的唯一行：

SELECT product_id FROM inventoryments 
MINUS 
SELECT product_id FROM order_items 
ORDER BY product_id;

UNION ALL实施例 的UNION操作者仅返回出现在任一结果不同的行，而UNION ALL操作者将返回所有行。该UNION ALL运营商不消除重复选择的行：

SELECT product_id FROM order_items 
UNION 
SELECT product_id FROM库存
ORDER BY product_id; 

SELECT location_id FROM locations 
UNION ALL 
SELECT location_id FROM departments 
ORDER BY location_id;