postgresql - PostgreSQL：帮我弄清楚如何使用表别名

Question

请保留我头上剩余的头发并帮助我为诸如此类的语句创建别名，我将在其中加入一个表及其查找表

//this does the location lookup
SELECT 
ludevice.device,
ludevice.description,
lulocation.location_long
FROM mopdb.ludevice
LEFT JOIN lulocation ON (ludevice.location_id = lulocation.location_id)
WHERE (ludevice.location_id = 1)
ORDER BY ludevice.device_id

编辑删除了令人困惑的评论
编辑所需的结果是一个用更少的字符实现此功能的语句

Answer 1

试试这个：

SELECT 
  d.device,
  d.description,
  l.location_long
FROM mopdb.ludevice d
LEFT JOIN lulocation l ON (d.location_id = l.location_id)
WHERE (d.location_id = 1)
ORDER BY d.device_id

或者稍微短一点，这要归功于USING：

SELECT 
  d.device,
  d.description,
  l.location_long
FROM mopdb.ludevice d
LEFT JOIN lulocation l USING (location_id)
WHERE (d.location_id = 1)
ORDER BY d.device_id