2.hive里的增删改查

1.hive的增删改查

1. 查询数据库

       hive> show databases;
       OK
       default
       Time taken: 0.254 seconds, Fetched: 1 row(s)
       hive>
       #defalut是默认数据库
   

2. 创建数据库

   hive> create database liuyao;
   OK
   Time taken: 0.055 seconds
   

3. 在hdfs里查看相关库数据

   #hdfs dfs -lsr /
   
   lsr: DEPRECATED: Please use 'ls -R' instead.
   drwxr-xr-x   - root supergroup          0 2017-07-12 10:45 /user/hive
   drwxr-xr-x   - root supergroup          0 2017-07-12 10:45 /user/hive/warehouse
   drwxr-xr-x   - root supergroup          0 2017-07-12 10:45 /user/hive/warehouse/liuyao.db
   #每创建一个数据库都会在对应的hdfs里的/user/hive/warehouse生成一个xx.db的目录
   #一个数据库对应一个目录
   

4. 在mysql里查看相关库数据

   mysql> use dbhive;
   mysql> select * from DBS;
   +-------+-----------------------+------------------------------------------------+---------+------------+------------+
   | DB_ID | DESC                  | DB_LOCATION_URI                                | NAME    | OWNER_NAME | OWNER_TYPE |
   +-------+-----------------------+------------------------------------------------+---------+------------+------------+
   |     1 | Default Hive database | hdfs://hadoop-1/user/hive/warehouse            | default | public     | ROLE       |
   |     2 | NULL                  | hdfs://hadoop-1/user/hive/warehouse/liuyao.db  | liuyao  | root       | USER       |
   +-------+-----------------------+------------------------------------------------+---------+------------+------------+
   #创建的库相关信息都维护在mysql里
   

5. 创建表

   hive> use liuyao;
   OK
   Time taken: 0.057 seconds
   hive> create table test(id int, name string);
   OK
   Time taken: 0.458 seconds
   hive>
   

6. 在mysql里查看相关表数据

   mysql> select * from TBLS;
   +--------+-------------+-------+------------------+-------+-----------+-------+----------+---------------+--------------------+--------------------+
   | TBL_ID | CREATE_TIME | DB_ID | LAST_ACCESS_TIME | OWNER | RETENTION | SD_ID | TBL_NAME | TBL_TYPE      | VIEW_EXPANDED_TEXT | VIEW_ORIGINAL_TEXT |
   +--------+-------------+-------+------------------+-------+-----------+-------+----------+---------------+--------------------+--------------------+
   |      1 |  1499871180 |     2 |                0 | root  |         0 |     1 | test     | MANAGED_TABLE | NULL               | NULL               |
   +--------+-------------+-------+------------------+-------+-----------+-------+----------+---------------+--------------------+--------------------+
   1 row in set (0.00 sec)
   #DB_ID关联管理库ID
   

7. 在hdfs里产生相关表数据

   #hdfs dfs -lsr /
   drwxr-xr-x   - root supergroup          0 2017-07-12 10:53 /user/hive/warehouse/liuyao.db/test
   

8. 插入数据

   hive> use liuyao;
   OK
   Time taken: 0.133 seconds
   hive> insert into test values(2,"tom");
   WARNING: Hive-on-MR is deprecated in Hive 2 and may not be available in the future versions. Consider using a different execution engine (i.e. spark, tez) or using Hive 1.X releases.
   Query ID = root_20170712111559_38d90f7b-845d-441c-9fc2-77ceef15c446
   Total jobs = 3
   Launching Job 1 out of 3
   Number of reduce tasks is set to 0 since there's no reduce operator
   Starting Job = job_1498146166646_0003, Tracking URL = http://hadoop-1:8088/proxy/application_1498146166646_0003/
   Kill Command = /soft/hadoop-2.7.3/bin/hadoop job  -kill job_1498146166646_0003
   Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 0
   2017-07-12 11:16:08,543 Stage-1 map = 0%,  reduce = 0%
   2017-07-12 11:16:14,960 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 1.65 sec
   MapReduce Total cumulative CPU time: 1 seconds 650 msec
   Ended Job = job_1498146166646_0003
   Stage-4 is selected by condition resolver.
   Stage-3 is filtered out by condition resolver.
   Stage-5 is filtered out by condition resolver.
   Moving data to directory hdfs://hadoop-1/user/hive/warehouse/liuyao.db/test/.hive-staging_hive_2017-07-12_11-15-59_225_3827478452355860952-1/-ext-10000
   Loading data to table liuyao.test
   MapReduce Jobs Launched:
   Stage-Stage-1: Map: 1   Cumulative CPU: 1.65 sec   HDFS Read: 4060 HDFS Write: 73 SUCCESS
   Total MapReduce CPU Time Spent: 1 seconds 650 msec
   OK
   Time taken: 17.353 seconds
   hive>
   

9. insert会产生mr作业

   

10. 查看数据

    hive>
    hive> select * from test;
    OK
    1	tom
    2	tom
    Time taken: 0.276 seconds, Fetched: 2 row(s)
    hive>
    #select * from test 默认从hdfs里的相关文件里读取数据