Question

我形成了一个有点傻的问题。但是，让我在一个我正在努力的例子中表达问题。

我的查询给出了以下结果：

如您所见，除最后一列外，一切都是一样的。如何将结果连接到一行，其中包含最后一列的两个值。

我的查询：

select tp.tp_vorname as PatientFirstName, tp.tp_nachname as PatientLastName,
       tp.tp_geburtsdatum as patientBirthday, pt.pt_id, te.te_startzeit as StartTime, 
       te.te_endzeit As EndTime, te_datecreated as DateCreated, tpw.li_id_warnungen as Warning
from termin_patient tp
INNER JOIN patienten_termin pt
    on tp.tp_id = pt.tp_id
INNER JOIN termin te
    on te.te_id = pt.pt_id
LEFT JOIN terminpatient_warnungen tpw
on tp.tp_id = tpw.tp_id
where pt.pt_id = te.te_id and tp.tp_id=91168 and 
      te.te_startzeit >= '2017-05-24' 
  AND te.te_startzeit <  '2017-06-02'

Answer 1

您可以在所有GROUP BY列上使用SELECT（但不能在最后一列tpw.li_id_warnungen上使用），并将最后一列汇总到一个字段中。

PostgreSQL解决方案：

您可以使用GROUP BY和STRING_AGG使用以下解决方案。要使用tpw.li_id_warnungen上的STRING_AGG列，您必须CAST将值TEXT。另一种解决方案，而不是使用CAST，可能是在列上使用直接转换tpw.li_id_warnungen::text。

SELECT 
    tp.tp_vorname AS PatientFirstName, 
    tp.tp_nachname AS PatientLastName,
    tp.tp_geburtsdatum AS patientBirthday, 
    pt.pt_id, 
    te.te_startzeit AS StartTime, 
    te.te_endzeit AS EndTime, 
    te_datecreated AS DateCreated, 
    STRING_AGG(CAST(tpw.li_id_warnungen AS TEXT), ',') AS Warning
FROM 
    termin_patient tp INNER JOIN patienten_termin pt ON tp.tp_id = pt.tp_id
    INNER JOIN termin te ON te.te_id = pt.pt_id
    LEFT JOIN terminpatient_warnungen tpw ON tp.tp_id = tpw.tp_id
WHERE 
    pt.pt_id = te.te_id 
    AND tp.tp_id = 91168 
    AND te.te_startzeit >= '2017-05-24' 
    AND te.te_startzeit < '2017-06-02' 
GROUP BY 
    tp.tp_vorname, 
    tp.tp_nachname, 
    tp.tp_geburtsdatum, 
    pt.pt_id, 
    te.te_endzeit, 
    te_datecreated

使用其他警告名称（在评论中描述），您的查询将如下所示（不再需要CAST或直接投射）：

SELECT 
    tp.tp_vorname AS PatientFirstName, 
    tp.tp_nachname AS PatientLastName,
    tp.tp_geburtsdatum AS patientBirthday, 
    pt.pt_id, 
    te.te_startzeit AS StartTime, 
    te.te_endzeit AS EndTime, 
    te_datecreated AS DateCreated, 
    STRING_AGG(lip.li_name, ',') AS Warning
FROM 
    termin_patient tp INNER JOIN patienten_termin pt ON tp.tp_id = pt.tp_id
    INNER JOIN termin te ON te.te_id = pt.pt_id
    LEFT JOIN terminpatient_warnungen tpw ON tp.tp_id = tpw.tp_id 
    LEFT JOIN li_patientenwarnung lip ON tpw.li_id_warnungen = lip.li_id
WHERE 
    pt.pt_id = te.te_id 
    AND tp.tp_id = 91168 
    AND te.te_startzeit >= '2017-05-24' 
    AND te.te_startzeit < '2017-06-02' 
GROUP BY 
    tp.tp_vorname, 
    tp.tp_nachname, 
    tp.tp_geburtsdatum, 
    pt.pt_id, 
    te.te_endzeit, 
    te_datecreated

MySQL解决方案：

您可以使用GROUP BY和GROUP_CONCAT

在MySQL上使用以下解决方案

SELECT 
    tp.tp_vorname AS PatientFirstName, 
    tp.tp_nachname AS PatientLastName,
    tp.tp_geburtsdatum AS patientBirthday, 
    pt.pt_id, 
    te.te_startzeit AS StartTime, 
    te.te_endzeit AS EndTime, 
    te_datecreated AS DateCreated, 
    GROUP_CONCAT(tpw.li_id_warnungen) as Warning
FROM 
    termin_patient tp INNER JOIN patienten_termin pt ON tp.tp_id = pt.tp_id
    INNER JOIN termin te ON te.te_id = pt.pt_id
    LEFT JOIN terminpatient_warnungen tpw ON tp.tp_id = tpw.tp_id
    LEFT JOIN li_patientenwarnung lip ON tpw.li_id_warnungen = lip.li_id
WHERE 
    pt.pt_id = te.te_id 
    AND tp.tp_id=91168 
    AND te.te_startzeit >= '2017-05-24' 
    AND te.te_startzeit <  '2017-06-02' 
GROUP BY 
    tp.tp_vorname,
    tp.tp_nachname, 
    tp.tp_geburtsdatum,
    pt.pt_id,
    te.te_endzeit,
    te_datecreated

使用其他警告名称（在评论中描述），您的查询将如下所示：

SELECT 
    tp.tp_vorname AS PatientFirstName, 
    tp.tp_nachname AS PatientLastName,
    tp.tp_geburtsdatum AS patientBirthday, 
    pt.pt_id, 
    te.te_startzeit AS StartTime, 
    te.te_endzeit AS EndTime, 
    te_datecreated AS DateCreated, 
    GROUP_CONCAT(lip.li_name) as Warning
FROM 
    termin_patient tp INNER JOIN patienten_termin pt ON tp.tp_id = pt.tp_id
    INNER JOIN termin te ON te.te_id = pt.pt_id
    LEFT JOIN terminpatient_warnungen tpw ON tp.tp_id = tpw.tp_id
WHERE 
    pt.pt_id = te.te_id 
    AND tp.tp_id=91168 
    AND te.te_startzeit >= '2017-05-24' 
    AND te.te_startzeit <  '2017-06-02' 
GROUP BY 
    tp.tp_vorname,
    tp.tp_nachname, 
    tp.tp_geburtsdatum,
    pt.pt_id,
    te.te_endzeit,
    te_datecreated

Postgresql合并来自JOIN的相同列

1 个答案: