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  • Hive基本操作

    在hive命令终端直接导入文本数据:

    hive> LOAD DATA LOCAL INPATH '/home/simon/hive_test/a.txt' OVERWRITE INTO TABLE w_a;

     查看特征:

    hive> select A.usrid, A.age, B.time from w_a A join w_b B on A.usrid = B.usrid; 

    通过LOAD命令直接将hadoop文件系统上的文件导入,不加LOCAL

    hive> LOAD DATA INPATH '/user_name.data.utf.txt' OVERWRITE INTO TABLE u_info;

     hive数据导入另外一种方法:

    hive> insert into table w_d select usrid, age from w_a limit 2;

     从Hive导出数据到local本地

    hive> insert overwrite local directory '/home/badou/hive_test/data/1.txt' select usrid, age from w_a;

    从Hive导出数据到HDFS上

    hive> insert overwrite directory '/hive_data' select usrid, age from w_a;

    利用partition导入,查询数据

    hive> load data local inpath '/home/badou/hive_test/p1.txt' into table p_t_2;                       
    Copying data from file:/home/badou/hive_test/p1.txt
    Copying file: file:/home/badou/hive_test/p1.txt
    Loading data to table default.p_t_2
    Table default.p_t_2 stats: [numFiles=1, numRows=0, totalSize=72, rawDataSize=0]
    OK
    Time taken: 0.41 seconds
    hive> select * from p_t_2;
    OK
    user2   28      20170302
    user4   30      20170302
    user6   32      20170302
    user8   34      20170302
    Time taken: 0.081 seconds, Fetched: 4 row(s)
    hive> select * from p_t_2 where dt='20170302';                               
    Total jobs = 1
    Launching Job 1 out of 1
    Number of reduce tasks is set to 0 since there's no reduce operator
    Starting Job = job_201908120758_0009, Tracking URL = http://master:50030/jobdetails.jsp?jobid=job_201908120758_0009
    Kill Command = /usr/local/src/hadoop-1.2.1/libexec/../bin/hadoop job  -kill job_201908120758_0009
    Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0
    2019-08-14 20:36:11,750 Stage-1 map = 0%,  reduce = 0%
    2019-08-14 20:36:20,899 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 2.98 sec
    2019-08-14 20:36:26,020 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 2.98 sec
    MapReduce Total cumulative CPU time: 2 seconds 980 msec
    Ended Job = job_201908120758_0009
    MapReduce Jobs Launched: 
    Job 0: Map: 1   Cumulative CPU: 2.98 sec   HDFS Read: 283 HDFS Write: 72 SUCCESS
    Total MapReduce CPU Time Spent: 2 seconds 980 msec
    OK
    user2   28      20170302
    user4   30      20170302
    user6   32      20170302
    user8   34      20170302
    Time taken: 21.554 seconds, Fetched: 4 row(s)
    hive> 

    创建UDF函数:

    hive> create temporary function uppercase as 'com.badou.hive.udf.Uppercase';
    OK
    Time taken: 0.097 seconds
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  • 原文地址:https://www.cnblogs.com/hackerer/p/11343502.html
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