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原文链接： Scala对MongoDB的增删改查操作 转载请注明出处！
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依赖环境：jdk1.8、Scala 2.12、idea
mongodb Driver:3.1.1。注意，mongo for scala的驱动涉及多个jar(如下图)，依赖于mongo-java-driver.jar
这里使用的sbt管理依赖,直接在build.sbt中添加依赖：libraryDependencies += "org.mongodb" %% "casbah" % "3.1.1"（强烈建议使用该方法添加依赖）
一、创建数据库连接
A：不需要用户名和密码直接获取MongoDB。
// 无权限验证连接
def createDatabase(url: String, port: Int, dbName: String): MongoDB = {
MongoClient(url, port).getDB(dbName)
}
这里需要注意一下，在导入的jar包存在两个MongoClient类，一个来自于mongo-java-driver.jar的com.mongodb.MongoClient，另一个来自于casbah-core_2.12:3.1.1.jar的com.mongodb.casbah.MongoClient.前者是用于java调用，Scala使用后者!!!
因此导入包的时候要注意为：import com.mongodb.casbah.MongoClient
B:通过权限验证进行连接
//验证连接权限
def createDatabase(url: String, port: Int, dbName: String, loginName: String, password: String): MongoDB = {
var server = new ServerAddress(url, port)
//注意：MongoCredential中有6种创建连接方式，这里使用MONGODB_CR机制进行连接。如果选择错误则会发生权限验证失败
var credentials = MongoCredential.createCredential(loginName, dbName, password.toCharArray)
var mongoClient = MongoClient(server, List(credentials))
mongoClient.getDB(dbName)
}
这里需要注意的是MongoCredential.createCredential(),在MongoCredential中存在着六种认证机制，这里使用createCredential()进行创建，使用错误则将会验证失败
com.mongodb.MongoSecurityException: Exception authenticating
Caused by: com.mongodb.MongoCommandException: Command failed with error 18: ‘auth failed‘ on server localhost:27017. The full response is { "ok" : 0.0, "errmsg" : "auth failed", "code" : 18, "codeName" : "AuthenticationFailed" }
该方法注释如下：
/** * Creates a MongoCredential instance with an unspecified mechanism. The client will negotiate the best mechanism * based on the version of the server that the client is authenticating to. If the server version is 2.8 or higher, * the driver will authenticate using the SCRAM-SHA-1 mechanism. Otherwise, the driver will authenticate using the * MONGODB_CR mechanism. * * @param userName the user name * @param database the database where the user is defined * @param password the user‘s password */
二、数据添加
def testInsert(): Unit = {
for (i <- 1 to 100)
collection.insert(MongoDBObject("name" -> "Jack%d".format(i), "email" -> "jack%[email protected]".format(i), "age" -> i % 25, "birthDay" -> new SimpleDateFormat("yyyy-MM-dd").parse("2016-03-25")))
}
这里的collection是在下面创建的：
var collection= createDatabase("localhost", 27017, "mytest", "user", "123456").getCollection("user")
在进行数据插入的时候，如果不存在该collection则会自动创建（这里是user），如果document中不包含“_id”字段则会自动添加该字段。
DBCollection中存在一个save方法，该save方法区别于insert的地方在于当“_id”存在于集合中，save将会进行更新数据，而insert不会进行任何操作
根据需要选择适合的数据插入函数
存储之后数据如下：
{ "_id" : { "$oid" : "592ad4be45aefd09f4867f1e"} , "name" : "Jack86" , "email" : "[email protected]" , "age" : 11 , "birthDay" : { "$date" : "2016-03-24T16:00:00.000Z"}}
{ "_id" : { "$oid" : "592ad4be45aefd09f4867f1f"} , "name" : "Jack87" , "email" : "[email protected]" , "age" : 12 , "birthDay" : { "$date" : "2016-03-24T16:00:00.000Z"}}
{ "_id" : { "$oid" : "592ad4be45aefd09f4867f20"} , "name" : "Jack88" , "email" : "[email protected]" , "age" : 13 , "birthDay" : { "$date" : "2016-03-24T16:00:00.000Z"}}
{ "_id" : { "$oid" : "592ad4be45aefd09f4867f21"} , "name" : "Jack89" , "email" : "[email protected]" , "age" : 14 , "birthDay" : { "$date" : "2016-03-24T16:00:00.000Z"}}
三、数据更新修改
A：更新方式一
def testUpdate(): Unit = {
var query = MongoDBObject("name" -> "user1", "email" -> "[email protected]")
var value = MongoDBObject("name" -> "user1", "email" -> "[email protected]")
println("=========更新之前============")
var query02 = MongoDBObject("name" -> "user1")
collection.find(query02).forEach(x => println(x))
// query:根据此条件进行查询 value：把查询出来结果集的第一条数据设置为value
collection.update(query,value)
println("=========更新之后============")
collection.find(query02).forEach(x => println(x))
}
运行结果如下：（注意这里只更新了一条记录，并不是把所有符合结果的数据都进行更新）
B：更新方式二
def testUpdate02(): Unit = {
var query = MongoDBObject("name" -> "user1", "email" -> "[email protected]")
var value = new BasicDBObject("$set", new BasicDBObject("email", "[email protected]"))
// var value = MongoDBObject("$set",MongoDBObject("name" -> "user1", "email" -> "[email protected]"))
println("=========更新之前============")
var query02 = MongoDBObject("name" -> "user1")
collection.find(query02).forEach(x => println(x))
collection.update(query, value,true, true)
println("=========更新之后============")
collection.find(query02).forEach(x => println(x))
}
注意该方法：collection.update(query, value,true, true)。
第三个参数：when true, inserts a document if no document matches the update query criteria
第四个参数：when true, updates all documents in the collection that match the update query criteria, otherwise only updates one【当该值为true时，则更新所有的结果集数据，不过前提是value必须使用“$XXX”模式进行定义】。源码如下：
四、数据查询（建议看下这篇文章：MongoDB学习笔记(查询)）
def testSelect(): Unit ={
println("=========查询所有数据===================")
collection.find().forEach(x => println(x))
println("=========查询name = “user1” 同时email=“[email protected]”===================")
collection.find(MongoDBObject("name" -> "user1", "email" -> "[email protected]")).limit(3).forEach(x => println(x))
// 注意此处不能使用put添加其他查询条件，因为put返回的是HashMap,此处应该使用append进行添加查询条件
// var query = new BasicDBObject("name",new BasicDBObject("$in",("user145","user155"))).put("qty",new BasicDBObject("$in",(25.0,105.0))) 该方法错误
// 查询条件为： (name in ("user145","user155")) && (qty in (25.0,105.0))
println("=========查询 (name in (\"user145\",\"user155\")) && (qty in (25.0,105.0))===================")
var query = new BasicDBObject("name", new BasicDBObject("$in", ("user145", "user155"))).append("qty", new BasicDBObject("$in", (25.0, 105.0)))
collection.find(query).forEach(x => println(x))
println("=========查询 start >= 10 && end<= 80 的数据===================")
var query02 = new BasicDBObject("start", new BasicDBObject("$gte", 10)).append("end", new BasicDBObject("$lte", 80))
collection.find(query02).forEach(x => println(x))
}
查询结果如下：
五、数据删除
数据删除主要是构建一个查询条件，把符合该条件的所有数据都进行删除
def testDelete(): Unit ={
var query = MongoDBObject("name" -> "user1", "email" -> "[email protected]")
println("=========删除之前============")
collection.find(query).forEach(x => println(x))
//该参数只是一个查询条件，符合该条件的所有集合都将被删除。重点在于如何构建query
collection.remove(query)
println("=========删除之前============")
collection.find(query).forEach(x => println(x))
}
执行结果如下：
=========删除之前============
{ "_id" : { "$oid" : "592a0c8345aefd1d404c3ed9"} , "name" : "user1" , "email" : "[email protected]"}
{ "_id" : { "$oid" : "592a0c8345aefd1d404c3eda"} , "name" : "user1" , "email" : "[email protected]"}
{ "_id" : { "$oid" : "592a0c9845aefd0dfc2a1e21"} , "name" : "user1" , "email" : "[email protected]"}
{ "_id" : { "$oid" : "592a0c9845aefd0dfc2a1e23"} , "name" : "user1" , "email" : "[email protected]"}
{ "_id" : { "$oid" : "592a740f434a43d3b1529d0e"} , "name" : "user1" , "email" : "[email protected]"}
=========删除之后============
remove方法有如下四种，根据具体情况选取合适的方法：
--end