在mysql中排序:> ids = [11,31,29]=> [11, 31, 29]> User.where(id: ids).order("field(id, #{ids.join(',')})")在postgres中:def self.order_by_ids(ids) order_by = ["CASE"] ids.each_with_index do |id, index|
> User.where(id: ids).order("field(id, #{ids.join(',')})") 在postgres中: def self.order_by_ids(ids) order_by = ["CASE"] ids.each_with_index do |id, index| order_by << "WHEN id='#{id}' THEN #{index}" end order_by << "END" order(order_by.join(" ")) end User....
窗口函数内的Order by降序聚合是指在窗口函数中使用Order by子句对数据进行排序,并在排序后的数据上进行聚合操作。 具体来说,窗口函数内的Order by降序聚合可以通过以下步骤实现: 首先,我们需要使用窗口函数来定义一个窗口,该窗口将确定我们要进行聚合操作的数据范围。可以使用窗口函数中的Partition by子句来指定分组...
aggs.answers.aggs.questions 中使用了两次,相当于 SQL 的 group by,属于 Bucket Aggregations Cardinality Aggregation 相当于 SQL 的 count(distinct(FIELD)),属于 Metrics Aggregations 还有一个很重要的概念:聚合后再聚合 Sub-Aggregations * 像例子中的 aggs.answers.aggs.questions,就是先用题目进行聚合,然后再将...
.orderBy('your_field') .snapshots(); stream.listen((QuerySnapshot snapshot) { // 在这里处理实时更新的数据 snapshot.docs.forEach((DocumentSnapshot doc) { // 处理每个文档的数据 print(doc.data()); }); }); } 在上述示例中,我们使用snapshots()方法创建了一个实时更新的流,并将其...
static final RunQueryOrderByField ACTIVITY_NAME Static value ActivityName for RunQueryOrderByField. static final RunQueryOrderByField ACTIVITY_RUN_END Static value ActivityRunEnd for RunQueryOrderByField. static final RunQueryOrderByField ACTIVITY_RUN_START Static value ActivityRunStart for Run...
select * from table order by field(id,1,3,4,2). How can I do the same thing with Postgres? Is it possible? Thanks to all. Please forgive my poor english. Subject Views Written By Posted Emulate mysql order by field 16946 andrea rossi ...
Thanks for this ticket. I was able to reproduce the crash on PostgreSQL with aJSONFieldwith a custom decoder. It's caused bythe different formatused in this case. Can you confirm that the following patch fix this issue for you?
its has Meta.ordering = ('relname__a_field_from_model_X',) We try to order the Entry model instances by its blog relationship field. Check it works with all relations (not just ForeignKeys). Let's work out what happens with backwards relations... I've added (although a bit co...
Bug #115587 MySQL fails to resolve order by a const field in a derived table Submitted: 15 Jul 2024 9:32Modified: 25 Jul 2024 1:24 Reporter: Diancheng Wang Email Updates: Status: Not a Bug Impact on me: None Category: MySQL Server: ParserSeverity: S3 (Non-critical) Version: ...