SQL更新top1行查询

Question

以下查询有效：

update  top(1) ShipBillInfo 
set     shipfirstname='kkk' 
where   CustomerId='134';

但是如果我尝试通过某些Id订购它会显示错误：例如：

update  top(1) ShipBillInfo 
set     shipfirstname='kkk' 
where   CustomerId='134' 
order by 
        OredrGUID desc;

Answer 1

With cte as (
select  top(1) shipfirtsname  
From ShipBillInfo 
where   CustomerId='134' 
order by  OredrGUID desc)
Update cte set shipfirstname='abc';

Answer 2

你为什么不这样做：

update ShipBillInfo 
set shipfirstname='kkk' 
where OrderGUID = (select top (1) OrderGUID  
                   from ShipBillInfo 
                   where CustomerId = 134 
                   order by OredrGUID desc )

Answer 3

线程安全

对于线程安全解决方案，所提出的解决方案都不适用于我（某些行在同时执行时多次更新）。

这有效：

class ImageListFilter(admin.SimpleListFilter):

    title = _('Has photo')

    parameter_name = 'has_photo'

    def lookups(self, request, model_admin):

        return (
            ('yes', _('Yes')),
            ('no',  _('No')),
        )

    def queryset(self, request, queryset):

        if self.value() == 'yes':
            return queryset.filter(image__isnull=False).exclude(image='')

        if self.value() == 'no':
            return queryset.filter(Q(image__isnull=True) | Q(image__exact=''))


class UserAdmin(admin.ModelAdmin):

    list_filter = [ImageListFilter]

如果您想要返回更新项目的某些列，可以将其放入更新语句中：UPDATE Account SET sg_status = 'A' WHERE AccountId = ( SELECT TOP 1 AccountId FROM Account WITH (UPDLOCK) --this makes it thread safe ORDER BY CreationDate ) （OUTPUT INSERTED.AccountId和SET之间）