大数据实时计算Spark学习笔记（10）—— Spar SQL(2) -JDBC方式操作表

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/u012292754/article/details/85334923

1 Spark SQL 的 JDBC 方式

• POM 文件添加依赖

 <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.38</version>
    </dependency>

1.1 查询数据库

import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;

public class SQLJDBCJava {
    public static void main(String[] args) {

        SparkSession session = SparkSession.builder()
                .appName("JDBC")
                .config("spark.master","local[2]")
                .getOrCreate();

        String url = "jdbc:mysql://localhost:3306/weblog";
        String table = "city";

        Dataset<Row> df= session.read()
                .format("jdbc")
                .option("url", url)
                .option("dbtable",table)
                .option("user", "root")
                .option("password", "root")
                .option("driver","com.mysql.jdbc.Driver")
                .load();

        df.show();

    }
}

1.1.1 向数据库写数据

import org.apache.spark.sql.Column;
import org.apache.spark.sql.Dataset;
import org.apache.spark.sql.Row;
import org.apache.spark.sql.SparkSession;

import java.util.Properties;

public class SQLJDBCJava {
    public static void main(String[] args) {

        SparkSession session = SparkSession.builder()
                .appName("JDBC")
                .config("spark.master","local[2]")
                .getOrCreate();

        String url = "jdbc:mysql://localhost:3306/weblog?useSSL=false";
        String table = "city";

        Dataset<Row> df= session.read()
                .format("jdbc")
                .option("url", url)
                .option("dbtable",table)
                .option("user", "root")
                .option("password", "root")
                .option("driver","com.mysql.jdbc.Driver")
                .load();

        //df.show();

        //投影查询
        Dataset<Row> df2 = df.select(new Column("cms_id"),new Column("times"));
        df2 = df2.where("cms_id like '143%'");

        Properties prop = new Properties();
        prop.put("user","root");
        prop.put("password","root");
        prop.put("driver","com.mysql.jdbc.Driver");

        //写入
        df2.write().jdbc(url,"city2",prop);
        df2.show();

    }
}