sql - 使用 UPDATE FROM 批量设置字段

Question

我有以下查询，用于提取车辆 ID、注册信息、驾驶员 ID 和驾驶员姓名。您看到此查询中引用的 _core_people 表也是我希望设置为车牌的字段。

这是查询:

SELECT fv._plate, cp._people_name
FROM
_fleet_vehicle fv,
_fleet_vehicle_status fvs,
_core_people cp,
_fleet_allocation fa
WHERE 
cp._id_hierarchy = fv._id_hierarchy
AND fv._id_status = fvs._id
AND fvs._status_live = 1
AND fa._id_person = cp._id
AND fa._id_vehicle = fv._id
AND fa._alloc_end_date IS NULL
ORDER BY cp._people_name ASC

现在，我想编写一个 UPDATE...FROM 子句，利用此子句将 _core_people._plate (此处未显示)设置为其车辆的车牌字段.

但是，我不确定如何构建 UPDATE...FROM 子句。

此外，一些司机有两辆车。还能用吗？

提前致谢!

Answer 1

UPDATE  _core_people
SET     _plate = fv._plate
FROM    _fleet_vehicle fv,
        _fleet_vehicle_status fvs,
        _core_people cp,
        _fleet_allocation fa
WHERE   cp._id_hierarchy = fv._id_hierarchy
        AND fv._id_status = fvs._id
        AND fvs._status_live = 1
        AND fa._id_person = cp._id
        AND fa._id_vehicle = fv._id
        AND fa._alloc_end_date IS NULL

如果 _core_people 符合条件的记录超过 1 条，_core_people 将仅更新为其中一条(无法准确判断是哪一条) .