内部联接SQL查询
下一个sql语句工作正常。它同时显示patient_id和serv_name,但我尝试显示patient_name而不是patient_id内部联接SQL查询,sql,Sql,下一个sql语句工作正常。它同时显示patient_id和serv_name,但我尝试显示patient_name而不是patient_id SELECT C1.patient_id, S.serv_name FROM Checkup_Details C INNER JOIN Services S ON (C.serv_id=S.serv_id), Checkup C1 WHERE C1.today = DATE() AND C1.check_id=C.chec
SELECT C1.patient_id, S.serv_name
FROM
Checkup_Details C
INNER JOIN Services S ON (C.serv_id=S.serv_id),
Checkup C1
WHERE
C1.today = DATE() AND C1.check_id=C.check_id
ORDER BY C.check_id
那么,我应该如何通过添加这个sql语句来实现这一点呢
INNER JOIN Patient P ON (C1.patient_id=P.patient_id)
但是我不知道有多精确。假设现场患者的名字在检查细节中,你必须
SELECT C1.patient_name ...
取而代之的是
SELECT C1.patient_id ...
只需添加internaljoin子句即可获得表Patient的列,并通过p.Patient\u名称更改C1.Patient\u id
SELECT P.patient_name, S.serv_name
FROM
Checkup_Details C
INNER JOIN Services S ON (C.serv_id=S.serv_id),
INNER JOIN Patient P ON (C1.patient_id=P.patient_id)
Checkup C1
WHERE
C1.today = DATE() AND C1.check_id=C.check_id
ORDER BY C.check_id
您不应该混合使用隐式和显式
join
语法。一条简单的规则:在from
子句中不要使用逗号:
SELECT C1.patient_id, S.serv_name
FROM Checkup_Details C INNER JOIN
Services S
ON C.serv_id = S.serv_id INNER JOIN
Checkup C1
ON C1.check_id = C.check_id INNER JOIN
Patient P
ON C1.patient_id = P.patient_id
WHERE C1.today = DATE()
ORDER BY C.check_id;