【包是全网最详细的负载均衡haproxy】

需求：

1.hive建表语句，导入数据语句，从linux文件系统导入

create table student(
   stu_name   string,
   course     string,
   score      int
)
row format delimited
fields terminated by ',';

load data local inpath '/root/stu.txt' into table student;

select * from default.student;

2.使用sparksql查询上述表，期望结果如下，并且将计算结果添加到mysql

【注：表名前边加上数据库。如：default.student】

from pyspark.sql import SparkSession

if __name__ == '__main__':
    spark = SparkSession.builder \
        .appName("测试") \
        .config("hive.metastore.uris", 'thrift://hadoop11:9083') \
        .enableHiveSupport() \
        .getOrCreate()


    df = spark.sql("""
        select stu_name,
               max(case when course='语文' then score else null end) chinese,
               max(case when course='数学' then score else null end) math,
               max(case when course='英语' then score else null end) english
        from default.student
        group by stu_name
    """)

    props = {'user': 'root', 'password': '123456', 'driver': 'com.mysql.jdbc.Driver'}
    df.write.jdbc(url='jdbc:mysql://hadoop11:3306/test1', table='df_student', properties=props)

    spark.stop()

sql结果：