Metabase 上怎么使用mongodb查询

JSON reader was expecting a value but found 'db'. 报错
运行如下,有人知道是什么原因吗
db.young.aggregate({
$group:{
_id: {
appName: "$appName"
},
count: {
"$sum": 1
}
}
})

Hi @youngstone
Only Native query is supported. Make your question in the interface and convert it to Native query:
https://www.metabase.com/docs/latest/users-guide/custom-questions.html#viewing-the-sql-that-powers-your-question

本机查询是什么意思,我就是在metabase上的编辑器上查询的。metabase支持mongodb语句查询吗,支持,麻烦给个例子,例如mysql 查询 select * from young