在之前的帖子就说过spark不支持hive的修改和删除操作,但是spark支持删除hive的分区,这也能实现一定情况下的删除需求,而且spark 2.3.0操作分区表有bug,spark2.3.3能正常操作hive分区表,也提到过如何升级spark。
1、Spark创建分区表
spark创建分区表的代码
val data = Array(("001", "张三", 21, "2018"), ("002", "李四", 18, "2017"))
val df = spark.createDataFrame(data).toDF("id", "name", "age", "year")
//可以将append改为overwrite,这样如果表已存在会删掉之前的表,新建表
df.write.mode("append").partitionBy("year").saveAsTable("new_test_partition")
hive查看分区
desc new_test_partition;
或
show create table new_test_partition;
根据下面的结果可以看到新建的表确实有分区字段year
hive> desc new_test_partition;
OK
id string
name string
age int
year string
# Partition Information
# col_name data_type comment
year string
Time taken: 0.432 seconds, Fetched: 9 row(s)
2、向已存在的分区表插入数据
2.1 Spark创建的分区表
df.write.mode("append").partitionBy("year").saveAsTable("new_test_partition")
2.2 在Hive命令行创建分区表
create table test_partition (
id string comment 'ID',
name string comment '名字',
age int comment '年龄'
)
comment '测试分区'
partitioned by (year int comment '年')
ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' ;
2.3 spark 保存分区数据
df.write.mode("append").partitionBy("year").saveAsTable("test_partition")
出现异常
Exception in thread "main" org.apache.spark.sql.AnalysisException: The format of the existing table dkl.test_partition is `HiveFileFormat`. It doesn't match the specified format `ParquetFileFormat`.;
解决方法
用fomat指定格式
df.write.mode("append").format("Hive").partitionBy("year").saveAsTable("test_partition")
其他方法
df.createOrReplaceTempView("temp_table")
sql("insert into test_partition select * from temp_table")
df.write.insertInto("test_partition")
insertInto会根据建表分区来自动插入到指定分区
附:完整代码
package com.dkl.blog.spark.hive
import org.apache.spark.sql.SparkSession
/**
* 博客:Spark操作Hive分区表
* https://dongkelun.com/2018/12/04/sparkHivePatition/
*
*/
object SparkHivePatition {
def main(args: Array[String]): Unit = {
val spark = SparkSession
.builder()
.appName("SparkHive")
.master("local")
.config("spark.sql.parquet.writeLegacyFormat", true)
.enableHiveSupport()
.getOrCreate()
import spark.sql
val data = Array(("001", "张三", 21, "2018"), ("002", "李四", 18, "2017"))
val df = spark.createDataFrame(data).toDF("id", "name", "age", "year")
//创建临时表
df.createOrReplaceTempView("temp_table")
//切换hive的数据库
sql("use dkl")
// 1、创建分区表,可以将append改为overwrite,这样如果表已存在会删掉之前的表,新建表
df.write.mode("append").partitionBy("year").saveAsTable("new_test_partition")
//2、向Spark创建的分区表写入数据
df.write.mode("append").partitionBy("year").saveAsTable("new_test_partition")
sql("insert into new_test_partition select * from temp_table")
df.write.insertInto("new_test_partition")
//开启动态分区
sql("set hive.exec.dynamic.partition.mode=nonstrict")
//3、向在Hive里用Sql创建的分区表写入数据,抛出异常
// df.write.mode("append").partitionBy("year").saveAsTable("test_partition")
// 4、解决方法
df.write.mode("append").format("Hive").partitionBy("year").saveAsTable("test_partition")
sql("insert into test_partition select * from temp_table")
df.write.insertInto("test_partition")
//这样会抛出异常
// df.write.partitionBy("year").insertInto("test_partition")
spark.stop
}
}