sparksql实践_1

1.需求：

读取test表中的客群编码以及需要执行的获取客群明细的sql语句

执行获取客群明细sql

将客群编码与客群明细写入结果表中

2,.数据准备

drop table sospdm.tmp_yinfei_test;
create table sospdm.tmp_yinfei_test
(
 id      string comment '客群id'
,exe_sql string comment '执行sql'
) comment '客群编码+执行sql'
row format delimited fields terminated by '	'
;

drop table sospdm.tmp_yinfei_result;
create table sospdm.tmp_yinfei_result
(
 id      string comment '客群id'
,cust_num string comment '会员编码'
)comment '结果表,客群编码+客群明细' 
row format delimited fields terminated by '	'
;

create table sospdm.tmp_yinfei_cust_num
(
cust_num string comment '会员编码'
) comment '客群明细表';

insert overwrite table sospdm.tmp_yinfei_cust_num
select 'a' as cust_num from sospdm.dual union all 
select 'b' as cust_num from sospdm.dual union all 
select 'c' as cust_num from sospdm.dual ;

insert overwrite table sospdm.tmp_yinfei_test
select '1' as id,'select cust_num from sospdm.tmp_yinfei_cust_num' from dual union all 
select '2' as id,'select cust_num from sospdm.tmp_yinfei_cust_num where cust_num in ('a','b')' from dual 
;

3.编码实现

package spark

import org.apache.spark.SparkConf
import org.apache.spark.rdd.RDD
import org.apache.spark.sql._

object Execute extends App {


  case class Person(id: String, cust_num: String)

  val sparkConf = new SparkConf().setAppName("Read")
  val session = SparkSession.builder().config(sparkConf).enableHiveSupport().getOrCreate()
  //从表中获取客群以及执行sql语句
  val ex: Array[Row] = session.sql("select id,exe_sql from sospdm.tmp_yinfei_test").rdd.collect()

  import session.implicits._
  //结果表数据清除，或者采用分区表
  session.sql("truncate table sospdm.tmp_yinfei_result ")
  //遍历执行sql,与客群id进行笛卡尔关联
  for (row <- ex) {
    val id: String = row.getString(0)
    val ex_sql: String = row.getString(1)
    val id_rdd = session.sparkContext.parallelize(List(id))
    val cust_num = session.sql(ex_sql).rdd
    val idCust: RDD[(String, Row)] = id_rdd cartesian (cust_num)
    val result = idCust.map(person => {
      Person(person._1.toString, person._2.getString(0))
    }).toDF()
    //创建临时表
    result.registerTempTable("tmp_yinfei_cu")
    //结果数据插入结果表
    session.sql("insert into table sospdm.tmp_yinfei_result select id,cust_num from tmp_yinfei_cu")
  }
}

4.结果展示