查询以获得不同的结果

Question

我有一个查询要从多个表中获取数据。但是不知何故，由于一列，我从数据库中得到了重复的条目。

查询是：

SELECT
  BH.BusinessName, AppointmentStartTime, AppointmentEndTime, AppointmentStatus,
  AppointmentFor, AppointmentForID, AppointmentStatus, S.ServiceName
from Appointment A
INNER JOIN BusinessHost BH ON A.BusinessHostID = BH.BusinessHostID
INNER JOIN BusinessHostService BHS ON BHS.BusinessHostID=BH.BusinessHostID
INNER JOIN Services S ON S.ServiceID=BHS.ServiceID

输出是这样的：

+ --------------+--------------------+------------ ------+--------------------+----------------+---- --------------+--------------------+-------------- ------+
|企业名称 |约会开始时间 |约会结束时间 |预约状态 |预约|预约ID |预约状态 |服务名称 |
+ --------------+--------------------+------------ ------+--------------------+----------------+---- --------------+--------------------+-------------- ------+
|阿米特父子 | 02:00:00.0000000 | 02:15:00.0000000 |已添加 |摩托车 | 1006 |已添加 |树木栽培 |
|阿米特父子 | 02:00:00.0000000 | 02:15:00.0000000 |已添加 |摩托车 | 1006 |已添加 |园林绿化服务 |
|罗希特父子 | 02:30:00.0000000 | 02:45:00.0000000 |已添加 |摩托车 | 1006 |已添加 |树木栽培 |
|罗希特父子 | 02:30:00.0000000 | 02:45:00.0000000 |已添加 |摩托车 | 1006 |已添加 |园林绿化服务 |
+ --------------+--------------------+------------ ------+--------------------+----------------+---- --------------+--------------------+-------------- ------+

你能帮我写查询以获得想要的结果吗：

+ --------------+--------------------+------------ ------+--------------------+----------------+---- --------------+--------------------+-------------- ----------------------+
|企业名称 |约会开始时间 |约会结束时间 |预约状态 |预约|预约ID |预约状态 |服务名称 |
+ --------------+--------------------+------------ ------+--------------------+----------------+---- --------------+--------------------+-------------- ----------------------+
|阿米特父子 | 02:30:00.0000000 | 02:45:00.0000000 |已添加 |摩托车 | 1006 |已添加 |树木栽培、景观美化服务 |
|罗希特父子 | 02:30:00.0000000 | 02:45:00.0000000 |已添加 |摩托车 | 1006 |已添加 |树木栽培、景观美化服务 |
+ --------------+--------------------+------------ ------+--------------------+----------------+---- --------------+--------------------+-------------- ----------------------+

Answer 1

您正在寻找字符串聚合。从 SQL Server 2017 开始，这可用于 STRING_AGG (https://docs.microsoft.com/de-de/sql/t-sql/functions/string-agg-transact-sql?view=sql-server-ver15):

SELECT
  bh.businessname, a.appointmentstarttime, a.appointmentendtime, a.appointmentstatus,
  a.appointmentfor, a.appointmentforid, a.appointmentstatus, bs.servicenames
FROM appointment a
JOIN businesshost bh ON bh.businesshostid = a.businesshostid
JOIN
(
  SELECT
    bhs.businesshostid,
    STRING_AGG(s.servicename, ', ') WITHIN GROUP (ORDER BY s.servicename) AS servicenames
  FROM businesshostservice bhs
  JOIN services s ON s.serviceid = bhs.serviceid
  GROUP BY bhs.businesshostid
) bs ON bs.businesshostid = bh.businesshostid
ORDER BY bh.businessname, a.appointmentstarttime;

查询以获得不同的结果

Query to get distinct results

sql

sql-server

string-aggregation