如何更新嵌入列表中的项目? [英] How to update an item in a embedded list?
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问题描述
我有一个名为update"的 josn,它有一个嵌入的列表评论",如下所示:
I have a josn named "update",and it has an embedded list "comments" like this:
{
id: "update/0",
//comments contains elements with type:comment
comments: [{
id:"comment/0"
content:"old first level comment content..."
children:[{
id:"comment/00",
content:""old second level comment content...",
children[...]
}
]
}]
}
问题是:
1, How to replace "old first level comment content..." with "new first level
comment content..." by ids "update/0" and "comment/0"?
2, How to replace "old second level comment content..." with "new second level
comment content..." by ids "update/0","comment/0" and "comment/00"?
推荐答案
首先是您要查找的查询:
First the queries you are looking for:
r.table("update").get("update/0").update(function(doc) {
return doc.merge({
comments: doc("comments").map(function(comment) {
return r.branch(
comment("id").eq("comment/0"),
comment.merge({
content: "new first level comment content..."
}),
comment
)
})
})
}).run(...)
第二个:
r.table("update").get("update/0").update(function(doc) {
return doc.merge({
comments: doc("comments").map(function(comment) {
return r.branch(
comment("id").eq("comment/0"),
comment.merge({
children: comment("children").map(function(child) {
return r.branch(
child("id").eq("comment/00"),
child.merge({
content: "new second level comment content..."
}),
child
)
})
}),
comment
)
})
})
}).run(...)
您可能希望将数据拆分到多个表中以进行连接.在您的情况下,表更新"和表评论".您的餐桌评论可以为孩子们加入.
You probably want to split your data in multiple tables to do joins. In your case, a table "update" and a table "comment". Your table comment can join itself for the children.
您可以在此处找到更多信息:
You can find more information here:
如果您有更多问题,请告诉我.
If you have more questions, let me know.
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