Spark学习小记-（3）pyspark连接hive库表sql操作

参考：spark连接外部Hive应用

如果想连接外部已经部署好的Hive，需要通过以下几个步骤。

1)     将Hive中的hive-site.xml拷贝或者软连接到Spark安装目录下的conf目录下。

2)     打开spark shell，注意带上访问Hive元数据库的JDBC客户端（找到连接hive元mysql数据库的驱动）

$ bin/spark-shell  --jars mysql-connector-java-5.1.27-bin.jar

这里用的是pyspark

[root@hadoop02 spark]# bin/pyspark --jars /opt/module/hive/lib/mysql-connector-java-5.1.27-bin.jar

测试命令行操作

操作完成后可以成功打开：[root@hadoop02 spark]# bin/pyspark --jars /opt/module/hive/lib/mysql-connector-java-5.1.27-bin.jar 

Python 2.7.5 (default, Apr  2 2020, 13:16:51) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-39)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
Warning: Ignoring non-spark config property: export=JAVA_HOME=/opt/module/jdk1.8.0_144
Setting default log level to "WARN".
To adjust logging level use sc.setLogLevel(newLevel). For SparkR, use setLogLevel(newLevel).
21/01/09 22:23:27 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
21/01/09 22:23:31 WARN metastore.ObjectStore: Failed to get database global_temp, returning NoSuchObjectException
Welcome to
      ____              __
     / __/__  ___ _____/ /__
    _ / _ / _ `/ __/  '_/
   /__ / .__/\_,_/_/ /_/\_   version 2.1.1
      /_/

Using Python version 2.7.5 (default, Apr  2 2020 13:16:51)
SparkSession available as 'spark'.

## ## 测试spark建表
>>> from pyspark.sql import HiveContext,SparkSession
>>> hive_sql=HiveContext(spark)
>>> hive_sql.sql(''' create table test_youhua.test_pyspark_creat_tbl like test_youhua.youhua1 ''')
21/01/09 22:26:48 WARN metastore.HiveMetaStore: Location: hdfs://hadoop02:9000/user/hive/warehouse/test_youhua.db/test_pyspark_creat_tbl specified for non-external table:test_pyspark_creat_tbl
DataFrame[]

这时去hive库查可以看到已经通过spark操作生成了表 test_youhua.test_pyspark_creat_tbl

[root@hadoop02 hive]# bin/hive
ls: 无法访问/opt/module/spark/lib/spark-assembly-*.jar: 没有那个文件或目录

Logging initialized using configuration in jar:file:/opt/module/hive/lib/hive-common-1.2.1.jar!/hive-log4j.properties
hive> show databases;
OK
default
test_youhua
Time taken: 0.903 seconds, Fetched: 2 row(s)
hive> use test_youhua;
OK
Time taken: 0.038 seconds
hive> show tables;
OK
test_pyspark_creat_tbl
youhua1
Time taken: 0.028 seconds, Fetched: 2 row(s)

如果不想每次都手动添加驱动地址这么麻烦，可以在spark-defaults.conf里配置：

spark.executor.extraClassPath   /opt/module/hive/lib/mysql-connector-java-5.1.27-bin.jar
spark.driver.extraClassPath   /opt/module/hive/lib/mysql-connector-java-5.1.27-bin.jar

 测试提交操作

先写好

[root@hadoop02 spark]# vim input/test_pyspark_hive.py

import pyspark
from pyspark.sql import SparkSession
from pyspark import SparkConf,SparkContext
from pyspark.sql import HiveContext

sc=SparkSession.builder.master("local")
    .appName('first_name')
    .config('spark.executor.memory','2g')
    .config('spark.driver.memory','2g')
    .enableHiveSupport()
    .getOrCreate()
hive_sql=HiveContext(sc)
hive_sql.sql(''' create table test_youhua.test_spark_create_tbl1 like test_youhua.youhua1 ''')
hive_sql.sql(''' insert overwrite table test_youhua.test_spark_create_tbl1 select * from test_youhua.youhua1 ''')

再提交

[root@hadoop02 spark]# spark-submit input/test_pyspark_hive.py

可以看到操作成功：