从子查询 SQL 服务器更新

Question

如何使用 UPDATE 语句中的子查询？这是我的查询：

UPDATE car_availability
SET    availability_status = 'GOOD'
FROM   car_trip AS TRIP
WHERE  car_availability.car_no = TRIP.car_no 
AND NOT EXISTS (SELECT DISTINCT A.car_No 
                FROM   car_maintenance A 
                WHERE  A.car_no = TRIP.vehicle_id 
                AND    start_date = TRIP.workday)
AND EXISTS (SELECT DISTINCT B.car_No 
            FROM   car_maintenance B 
            WHERE  B.car_no = TRIP.vehicle_id 
            AND end_date IS NOT NULL)

我得到一个错误'FROM clause in UPDATE and DELETE statements cannot contain subquery sources or joins.'

我想将 availability_status 更新为 GOOD，其中 car_maintenance 中的汽车 start_date 等于 car_trip 的工作日和 [= 中的汽车20=] 其结束日期不为空。

Answer 1

正如@McNets 所说，您需要将 car_availability table 添加到 FROM 子句中。试试这个：

UPDATE CA
SET    availability_status = 'GOOD'
FROM   car_availability CA
JOIN car_trip AS TRIP ON CA.car_no = TRIP.car_no 
WHERE NOT EXISTS (SELECT DISTINCT A.car_No 
                FROM   car_maintenance A 
                WHERE  A.car_no = TRIP.vehicle_id 
                AND    start_date = TRIP.workday)
AND EXISTS (SELECT DISTINCT B.car_No 
            FROM   car_maintenance B 
            WHERE  B.car_no = TRIP.vehicle_id 
            AND end_date IS NOT NULL)

从子查询 SQL 服务器更新

UPDATE FROM WHERE Subquery SQL Server

mysql

data-warehouse

sql-server-2008

sql-update