MongoDB API 参考

const mongodb = context.services.get("mongodb-atlas");
const admin = mongodb.admin();

const mongodb = context.services.get("mongodb-atlas");
const admin = mongodb.admin();
const dbNames = admin.getDBNames();

const mongodb = context.services.get("mongodb-atlas");
const db = mongodb.db("myDB");

const mongodb = context.services.get("mongodb-atlas");
const db = mongodb.db("myDB");
const collectionNames = db.getCollectionNames();

const mongodb = context.services.get("mongodb-atlas");
const db = mongodb.db("myDB");
const collection = db.collection("myCollection");

const query = { "reviews.0": { "$exists": true } };
const projection = { "_id": 0 };
return itemsCollection.find(query, projection)
  .sort({ name: 1 })
  .toArray()
  .then(items => {
    console.log(`Successfully found ${items.length} documents.`)
    items.forEach(console.log)
    return items
  })
  .catch(err => console.error(`Failed to find documents: ${err}`))

const query = { "quantity": { "$gte": 25 } };
const projection = {
 "title": 1,
 "quantity": 1,
}
return itemsCollection.findOne(query, projection)
  .then(result => {
    if(result) {
      console.log(`Successfully found document: ${result}.`);
    } else {
      console.log("No document matches the provided query.");
    }
    return result;
  })
  .catch(err => console.error(`Failed to find document: ${err}`));

// Find the document that describes "lego"
const query = { "name": "lego" };
// Set some fields in that document
const update = {
  "$set": {
    "name": "blocks",
    "price": 20.99,
    "category": "toys"
  }
};
// Return the updated document instead of the original document
const options = { returnNewDocument: true };
return itemsCollection.findOneAndUpdate(query, update, options)
  .then(updatedDocument => {
    if(updatedDocument) {
      console.log(`Successfully updated document: ${updatedDocument}.`)
    } else {
      console.log("No document matches the provided query.")
    }
    return updatedDocument
  })
  .catch(err => console.error(`Failed to find and update document: ${err}`))

// Find the document that describes "lego"
const query = { "name": "lego" };
// Replace it with a new document
const replacement = {
    "name": "blocks",
    "price": 20.99,
    "category": "toys"
};
// Return the original document as it was before being replaced
const options = { "returnNewDocument": false };
return itemsCollection.findOneAndReplace(query, replacement, options)
  .then(replacedDocument => {
    if(replacedDocument) {
      console.log(`Successfully replaced the following document: ${replacedDocument}.`)
    } else {
      console.log("No document matches the provided query.")
    }
    return updatedDocument
  })
  .catch(err => console.error(`Failed to find and replace document: ${err}`))

// Find the first document that has a quantity greater than 25
const query = { "quantity": { "$gte": 25 } };
// Sort the documents in order of descending quantity before
// deleting the first one.
const options = {
  "sort": { "quantity": -1 }
}
return itemsCollection.findOneAndDelete(query, options)
  .then(deletedDocument => {
    if(deletedDocument) {
      console.log(`Successfully deleted document that had the form: ${deletedDocument}.`)
    } else {
      console.log("No document matches the provided query.")
    }
    return deletedDocument
  })
  .catch(err => console.error(`Failed to find and delete document: ${err}`))

const newItem = {
  "name": "Plastic Bricks",
  "quantity": 10,
  "category": "toys",
  "reviews": [{ "username": "legolover", "comment": "These are awesome!" }]
};
itemsCollection.insertOne(newItem)
  .then(result => console.log(`Successfully inserted item with _id: ${result.insertedId}`))
  .catch(err => console.error(`Failed to insert item: ${err}`))

const doc1 = { "name": "basketball", "category": "sports", "quantity": 20, "reviews": [] };
const doc2 = { "name": "football",   "category": "sports", "quantity": 30, "reviews": [] };
return itemsCollection.insertMany([doc1, doc2])
  .then(result => {
    console.log(`Successfully inserted ${result.insertedIds.length} items!`);
    return result
  })
  .catch(err => console.error(`Failed to insert documents: ${err}`))

const query = { "name": "football" };
const update = {
  "$push": {
    "reviews": {
      "username": "tombradyfan",
      "comment": "I love football!!!"
    }
  }
};
const options = { "upsert": false };
itemsCollection.updateOne(query, update, options)
  .then(result => {
    const { matchedCount, modifiedCount } = result;
    if(matchedCount && modifiedCount) {
      console.log(`Successfully added a new review.`)
    }
  })
  .catch(err => console.error(`Failed to add review: ${err}`))

const query = {};
const update = { "$mul": { "quantity": 10 } };
const options = { "upsert": false }
return itemsCollection.updateMany(query, update, options)
  .then(result => {
    const { matchedCount, modifiedCount } = result;
    console.log(`Successfully matched ${matchedCount} and modified ${modifiedCount} items.`)
    return result
  })
  .catch(err => console.error(`Failed to update items: ${err}`))

const query = { "name": "lego" };
itemsCollection.deleteOne(query)
  .then(result => console.log(`Deleted ${result.deletedCount} item.`))
  .catch(err => console.error(`Delete failed with error: ${err}`))

const query = { "reviews": { "$size": 0 } };
itemsCollection.deleteMany(query)
  .then(result => console.log(`Deleted ${result.deletedCount} item(s).`))
  .catch(err => console.error(`Delete failed with error: ${err}`))

const pipeline = [
  { "$group": {
      "_id": "$customerId",
      "numPurchases": { "$sum": 1 },
      "numItemsPurchased": { "$sum": { "$size": "$items" } }
  } },
  { "$addFields": {
      "averageNumItemsPurchased": {
        "$divide": ["$numItemsPurchased", "$numPurchases"]
      }
  } }
]
return purchasesCollection.aggregate(pipeline).toArray()
  .then(customers => {
    console.log(`Successfully grouped purchases for ${customers.length} customers.`)
    for(const customer of customers) {
      console.log(`customer: ${customer._id}`)
      console.log(`num purchases: ${customer.numPurchases}`)
      console.log(`total items purchased: ${customer.numItemsPurchased}`)
      console.log(`average items per purchase: ${customer.averageNumItemsPurchased}`)
    }
    return customers
  })
  .catch(err => console.error(`Failed to group purchases by customer: ${err}`))

return itemsCollection.count({ "reviews.0": { "$exists": true } })
  .then(numDocs => console.log(`${numDocs} items have a review.`))
  .catch(err => console.error("Failed to count documents: ", err))

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const taskCollection = context.services.get("mongodb-atlas")
2
  .db("tracker").collection("tasks");
3
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return taskCollection.distinct("status", {})
5
  .then(results => {
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      console.log(JSON.stringify(results));
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      console.log(results.length);
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  })
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  .catch(err => console.error(err))

exports = async function(arg){
    const doc1 = { "name": "velvet elvis", "quantity": 20, "reviews": [] };
    const doc2 = { "name": "mock turtleneck",  "quantity": 30, "reviews": [] };
    var collection = context.services.get("mongodb-atlas")
        .db("store")
        .collection("purchases");
    return await collection.bulkWrite(
        [{ insertOne: doc1}, { insertOne: doc2}],
        {ordered:true});
};