CRUD

• Create
• Read
• Update
• Delete

Коллекция

@Serializable
data class Scholar(
  val name: String, 
  val group: String
)
val scholars = 
  mongoDatabase
  .getCollection<Scholar>()
  .apply { drop() }

Create

scholars.insertOne(Scholar("Penny", "Girls"))
scholars.insertOne("{'name': 'Amy', 'group': 'Girls' }")

Sending command '{
  "insert": "scholar", "ordered": true, "$db": "test", 
  "lsid": {"id": {"$binary": {
    "base64": "UonhTNRHQJy7Y1Sn1TodHQ==", "subType": "04"}}}, 
  "documents": [{"name": "Penny", "group": "Girls", 
    "_id": {"$oid": "642b8e7a5f80a934d58628c3"}}]}' 
  with request id 7 to database 
  test on connection [connectionId{localValue:3, serverValue:4}] 
  to server 127.0.0.1:27017

Create

scholars.insertMany(
  arrayOf("Sheldon", "Leonard", "Howard", "Raj")
    .map { Scholar(it, "Boys") }
)

{"insert": "scholar", "ordered": true, "$db": "test", 
"lsid": {...}, 
"documents": [
  {"name": "Sheldon", "group": "Boys", "_id": {...}}, 
  {"name": "Leonard", "group": "Boys", "_id": {...}}, 
  {"name": "Howard", "group": "Boys", "_id": {...}}, 
  {"name": "Raj", "group": "Boys", "_id": {...}}]}

Read

println(scholars.find().toList())
println(scholars.findOne("{name: 'Penny'}"))

{"find": "scholar", "filter": {"name": "Penny"}, "limit": 1, 
"singleBatch": true, "$db": "test", "lsid": {...}}

Received batch of 1 documents with cursorId 0 
from server 127.0.0.1:27017 Scholar(name=Penny, group=Girls)

Read

val foundStudents: FindIterable<Scholar> = 
  scholars.find(Scholar::group eq "Boys")
    .sort("{'name': 1}")
prettyPrintCursor(foundStudents)

{"find": "scholar", "filter": {"group": "Boys"}, 
"sort": {"name": 1}, "$db": "test", "lsid": {...}}

{"result": [
    { "name": "Howard",
      "group": "Boys" },
    { "name": "Leonard",
      "group": "Boys" },
    { "name": "Raj",
      "group": "Boys" },
    { "name": "Sheldon",
      "group": "Boys" }
]}

Filter

val bson1: Bson = Scholar::group eq "Boys"

infix fun <@OnlyInputTypes T> 
  KProperty<T?>.eq(value: T?): Bson = 
    Filters.eq(path(), value)

• Creates a filter that matches all documents where the value of the property equals the specified value. Note that this doesn’t actually generate a $eq operator, as the query language doesn’t require it.

Update

scholars.updateOne(
  (Scholar::name eq "Amy"),
  setValue(Scholar::name, "Amy Farrah Fowler")
)

{"update": "scholar", "ordered": true, "$db": "test", 
"lsid": {...}, 
"updates": [{
  "q": {"name": "Amy"}, 
  "u": {"$set": {"name": "Amy Farrah Fowler"}}}]}

Update

scholars.updateMany(
  "{'group' : 'Boys'}", "{'\$set' : {'group' : 'Man'}}")

{"update": "scholar", "ordered": true, "$db": "test", 
"lsid": {...}, 
"updates": [{
  "q": {"group": "Boys"}, 
  "u": {"$set": {"group": "Man"}}, 
  "multi": true}]}

Delete

scholars.deleteOne(Scholar::name eq "Penny")

{"delete": "scholar", "ordered": true, "$db": "test", 
"lsid": {...}, 
"deletes": [
  {"q": {"name": "Penny"}, 
  "limit": 1}]}

Delete

scholars.deleteMany(Scholar::group eq "Man")

{"delete": "scholar", "ordered": true, "$db": "test", 
"lsid": {...}, 
"deletes": [{
  "q": {"group": "Man"}, 
  "limit": 0}]}