如果主文檔不是null，則在子文檔中查詢

Question

我有這樣的架構

product: {
    _id: mongoose.Schema.Types.ObjectId,
    client_name: { type: String, required: [true, "Client Name is Required"]},
    invoice: {
        type:{
            professional_fee: { type: Number, required: [true, "Professional Fee is Required"]},
            approved_expense: { type: Number, default: 0},
            document_expense: { type: Number, default: 0},
            other_expense: { type: Number, default: 0},
            invoice_url: {type: String, default: null},
            created_on: {type: Date, default: Date.now()},
            modified_on: {type: Date, default: Date.now()}
        },
        default: null
    },
    created_on: {type: Date, default: Date.now()},
    modified_on: {type: Date, default: Date.now()}
}

我想找到 invoice.invoice_url == null 的所有文件。

我用過這個invoice.invoice_url = null

但它會給出一個錯誤。 因為在某些情況下，發票屬性是 null。

所以我只想在發票屬性不是 null 然后 invoice_url 是 null 時從 mongo 中查找

Answer 1

試試下面的查詢。

db.product.find(
    {"$and":[{"invoice":{"$ne":null}},
    {"invoice.invoice_url":{"$eq":null}}]}
)