求一个万能的sql更新语句

 update t_inventory i left join (select entry.id,entry.material m,entry.model model,sum(entry.amount) s from t_sys_sales_slip_entry entry where entry.id in
            <foreach collection="list" item="item" open="(" close=")" separator=",">
                #{item.id}
            </foreach>
         group by entry.material
        ) j on j.m=i.materialid and j.model=i.model set i.qty = (i.qty-j.s)
        where i.materialid in
        <foreach collection="list" item="item" open="(" close=")" separator="," index="i">
            #{item.sysmaterial.id}
        </foreach> and i.model in
        <foreach collection="list" item="item" open="(" close=")" separator=",">
            #{item.model.id}
        </foreach>

这个sql并不是一个万能的sql 存在的缺陷就是 当materialid相同 model不同时 只会更新这个materialid 的一条记录 在materialid相同时 能把in改成=就可以了 吧

请问咋判断 in中产品相同时 用= 不同时用in 呢 ？ 或者根本不用这么写 该这么写这条sql

http://blog.knowsky.com/208115.htm