如何使用Casbah更新mongoDB中嵌套的Arrayof对象

Question

我的MongoDB数据如下：-

      {
      "_id": 1,
      "categories":[
      {
      "categoryName": "Automobiles",
      "categoryId": 1,
      "catDisplayName": "language1",
      "subCategories": [
        {
            "subCategoryName": "cars",
            "subCategoryId": 1,
            "subCatDisplayName": "language2"
        },
        {
            "subCategoryName": "bykes",
            "subCategoryId": 2,
            "subCatDisplayName": "language3"
        }
    ]
},
{
    "categoryName": "Electronics",
    "categoryId": 2,
    "catDisplayName": "somelanguage1",
    "subCategories": [
        {
            "subCategoryName": "Mobiles",
            "subCategoryId": 1,
            "subCatDisplayName": "somelanguage2"
        },
        {
            "subCategoryName": "cameras",
            "subCategoryId": 2,
            "subCatDisplayName": "somelanguage3"
        }
       ]
      }
      ]
      }

我们正在尝试MongoDb Casbah的两个案例，以下案例是：-

1. 如果类别存在而子类别不存在，则更新子类别阵列中的子类别

2. 如果分类不存在且子类别不存在，则分别更新类别和子类别阵列中的类别和子分类

我的案例1代码看起来像这样，它运行良好

val builderObj = MongoDBObject.newBuilder
builderObj += "subCategoryName" -> "cycles"
builderObj += "subCategoryId" -> 3
builderObj += "subCategoryName" -> "language4"
builderObj.result ()
val query = MongoDBObject("categories.categoryName" -> "Automobiles")
val updatingdata = $addToSet("categories.$.subCategories" -> builderObj.result ())
collection.update(query,updatingdata,true,true)

但是如何为案例2写作我们正在尝试下面的

val builderObj1 = MongoDBObject.newBuilder
builderObj1 += "categoryName"-> "Entertainment"
builderObj1 += "categoryId"-> 3
builderObj1 += "catDisplayName"-> "somelanguage4"
val builderObj = MongoDBObject.newBuilder
builderObj += "subCategoryName" -> "Tickets"
builderObj += "subCatDisplayName"-> "language1"
builderObj += "subCategoryId" -> 1
builderObj.result ()
val query = MongoDBObject("categories.$.categoryName" -> "Entertainment") //Entertainment  Category doesn't exist in my data
val updatingdata = ? // How To Update the Cateroy and SubCategory at a time 
collection.update()

请给我建议，我在这里被打动了

致以最诚挚的问候GSY

Answer 1

由于您正在创建一个新类别，因此新类别的subCategories数组将为空。因此，您可以直接将其添加到新类别中。

val subCatBuilder = MongoDBObject.newBuilder
subCatBuilder += "subCategoryName" -> "Tickets"
subCatBuilder += "subCatDisplayName"-> "language1"
subCatBuilder += "subCategoryId" -> 1
subCatBuilder
val catBuilder = MongoDBObject.newBuilder
catBuilder += "categoryName"-> "Entertainment"
catBuilder += "categoryId"-> 3
catBuilder += "catDisplayName"-> "somelanguage4"
catBuilder += "subCategories" -> MongoDBList(subCatBuilder.result())
val query = MongoDBObject() // How do you know which elements of collection to update?
val updatingdata = $push("categories" -> catBuilder.result())
collection.update(query, updatingdata, true, true)

当然，这将更新collection的每个元素以添加新类别。如果你想更有选择性，你需要适当地更新query。