在Postgresql中加入1个表和2个不同的表

Question

我在Postgresql中有2个表。这两者都是不同的架构。我希望输出在共享屏幕截图中。

假设对于字段HDRConfig，如果输出值是SE，那么我希望输出为软件工程而不是SE。我如何用其余列显示这些，即HDRConfig，AbrConfig＆amp; SbrConfig？

Answer 1

简单//Ajax call for each process and update the UI accordingly $.get('/services/status/100').then(function(resp) { $('#service-100').html(resp.responseText); }) //server side code (express syntax) app.get('/services/status/:id ', function(req,res) { // Check if service is ready serviceManager.isReady(req.params.id, function(err, serviceStats) { if(err) { //do logic err here , maybe notify the ui if an error occurred res.send(err); return; } // notify the ui , that the service is ready to run , and hide loader res.send(serviceStats); }); }) ：

LEFT JOIN

的 SqlFiddleDemo

SELECT l0.Code_Desc AS HDRConfig,
       l1.Code_Desc AS AbrConfig,
       l2.Code_Desc AS SbrConfig
FROM Equipment e
LEFT JOIN Lookup l0
  ON e.HDRConfig = l0."Code"
LEFT JOIN Lookup l1
  ON e.AbrConfig = l1."Code"
LEFT JOIN Lookup l2
   ON e.SbrConfig = l2."Code";

使用correletad子查询（效率低下）：

╔═══════════════════════╦═══════════════════════╦══════════════════════╗
║      hdrconfig        ║      abrconfig        ║      sbrconfig       ║
╠═══════════════════════╬═══════════════════════╬══════════════════════╣
║ Software Engineering  ║ Software Engineering  ║ Software Engineering ║
║ (null)                ║ Analog System         ║ Floppy Primary       ║
╚═══════════════════════╩═══════════════════════╩══════════════════════╝

的 SqlFiddleDemo2