如何在MySql中显示多表列表

如何在mysql中显示多表列表 我有一个包含两个表的查询 一个用于患者，另一个用于检测新冠病毒-19的患者 我想让所有的病人看看他们是否接受了测试 如果进行了测试，则用其姓名显示结果 它只显示了检测过新冠病毒的患者，而不是每个人

请问如何解决这个问题

这是我的问题

SELECT patient.*  
,covidtest.covidTestResult ,subareas.areaname 
FROM 
( patient LEFT OUTER  JOIN subareas
   ON  patient.town_id = subareas.town_id ) LEFT OUTER join covidtest  ON 
patient.Idnumber = covidtest.Idnumber where 
patient.Idnumber=covidtest.Idnumber and 
covidtest.CovidTestDate=(select max(covidtest.CovidTestDate)from 
covidtest where patient.Idnumber=covidtest.Idnumber) group by covidtest.Idnumber
 UNION SELECT patient.*  ,covidtest.covidTestResult,subareas.areaname  FROM 
 ( patient LEFT OUTER   JOIN subareas   ON 
  patient.town_id = subareas.town_id ) LEFT OUTER join covidtest  ON 
  patient.Idnumber = covidtest.Idnumber  where patient.Idnumber=covidtest.Idnumber 
  and covidtest.CovidTestDate=(select max(covidtest.CovidTestDate) from covidtest where 
  patient.Idnumber=covidtest.Idnumber) group by covidtest.Idnumber;

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以下是您需要做的：

SELECT
    patient.*,
    covidtest.covidTestResult,
    subareas.areaname
FROM patient
left join subareas on patient.town_id = subareas.town_id
Left join lateral
    ( select covidTestResult from covidtest 
      where patient.Idnumber = covidtest.Idnumber
      order by CovidTestDate desc 
      limit 1
    ) covidtest on 1=1

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您的表结构和示例数据在哪里？