Question

我有一个表user_activities，其中有user_id，activity_id和comments列。 activity_id和user_id都是外键，活动表具有另一个属性activity_name。要获取具有特定user_id和activity_name的行，我可以使用：

FROM UserActivityMapping AS mapping
    INNER JOIN mapping.activityId AS activity
    WHERE userId = <something> AND activity.activityName = <something>

到目前为止，这么好。现在，给定Pair的{{1}}列表，我想删除所有这些行。这个列表可能很大..比如600-700项大。现在看起来我可以生成一个查询的大问题：

<UserId, ActivityName>

这显然不是最好的方法。我该怎么做？这样的事情会很棒：

DELETE ...
    WHERE (userId = userId[0] AND activity.activityName = activityName[0]) OR
          (userId = userId[1] AND activity.activityName = activityName[1]) OR
          ...

非常感谢任何帮助。

Answer 1

之前我遇到过类似的问题并写了一个相当简单的函数来动态构建hql

private String buildInClause(List<Integer> keys)  {
   String inClause = "object.id in (";
   for (Integer key : keys) {
     inClause += key + ',";
   }
   inClause = inClause.substring(0,inClause.length -1) + ")";  // strip off last comma and add a closing paren.
   return inClause;
}

对于您的问题，您可以稍微修改此方法

inClause = " userId || '-' || activity.activityName in (";

// loop over your pairs however they are passed in
inClause += "'" + userId + "-" + activityName + "',";
// strip off trailing coman and add closing paren
inClause = inClause.substring(0,inClause.length -1) + ")";  
// end loop

Hibernate IN子句超过多个属性

1 个答案: