SparkSQL对mysql的读写

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SparkSQL JDBC数据源

！：load这个方法不会真正读取mysql的数据

//1、创建sparkSession
val sparkSession: SparkSession = SparkSession.builder().appName("JdbcDataSource").master("local[*]").getOrCreate()
    import sparkSession.implicits._
//2、从数据库中读取数据
    val logs: DataFrame = sparkSession.read.format("jdbc").options(
      Map("url" -> "jdbc:mysql://localhost:3306/bigdata",
        "driver" -> "com.mysql.jdbc.Driver",
        "dbtable" -> "log",
        "user" -> "root",
        "password" -> ""
      )
    ).load()

    //logs.printSchema()输出schema信息
	
    //logs.filter($"age" >12) 过滤年龄大于12的人，查询结果包括了12
	//方式二，不包含12
/*    val filtered:Dataset[Row] = logs.filter(
      r => {
        r.getAs[Int](2) < 12
      }
    )
    filtered.show()*/

	
    val nlog: DataFrame = logs.select($"id",$"name",$"age"*10 as "new_age")
	//将数据写到mysql中
    val pope = new Properties()
    val props = new Properties()
    props.put("user","root")
    props.put("password","")
    nlog.write.mode("ignore").jdbc("jdbc:mysql://localhost:3306/bigdata", "logs1", props)
    logs.show()
    sparkSession.close()
    ```