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hive的使用
2019-04-15 01:03:15 】 浏览:18
Tags:hive 使用

第一部分 连接hive

服务器运行模式

虽然可以使用hive与shell交互的方式启动hive
[root@mini1 ~]# cd apps/hive/bin
[root@mini1 bin]# ll
总用量 32
-rwxr-xr-x. 1 root root 1031 4月 30 2015 beeline
drwxr-xr-x. 3 root root 4096 10月 17 12:38 ext
-rwxr-xr-x. 1 root root 7844 5月 8 2015 hive
-rwxr-xr-x. 1 root root 1900 4月 30 2015 hive-config.sh
-rwxr-xr-x. 1 root root 885 4月 30 2015 hiveserver2
-rwxr-xr-x. 1 root root 832 4月 30 2015 metatool
-rwxr-xr-x. 1 root root 884 4月 30 2015 schematool
[root@mini1 bin]# ./hive
hive>

客户端运行模式

但是界面并不好看,而hive也可以发布为服务(Hive thrift服务),然后可以使用hive自带的beeline去连接。如下

窗口1,开启服务

[root@mini1 ~]# cd apps/hive/bin
[root@mini1 bin]# ll
总用量 32
-rwxr-xr-x. 1 root root 1031 4月 30 2015 beeline
drwxr-xr-x. 3 root root 4096 10月 17 12:38 ext
-rwxr-xr-x. 1 root root 7844 5月 8 2015 hive
-rwxr-xr-x. 1 root root 1900 4月 30 2015 hive-config.sh
-rwxr-xr-x. 1 root root 885 4月 30 2015 hiveserver2
-rwxr-xr-x. 1 root root 832 4月 30 2015 metatool
-rwxr-xr-x. 1 root root 884 4月 30 2015 schematool
[root@mini1 bin]# ./hiveserver2

窗口2,作为客户端连接

[root@mini1 bin]# ./beeline
Beeline version 1.2.1 by Apache Hive
beeline> [root@mini1 bin]#
[root@mini1 bin]# ./beeline
Beeline version 1.2.1 by Apache Hive
beeline> !connect jdbc:hive2://localhost:10000
Connecting to jdbc:hive2://localhost:10000
Enter username for jdbc:hive2://localhost:10000: root
Enter password for jdbc:hive2://localhost:10000: ******
Connected to: Apache Hive (version 1.2.1)
Driver: Hive JDBC (version 1.2.1)
Transaction isolation: TRANSACTION_REPEATABLE_READ
0: jdbc:hive2://localhost:10000>

可能出现错误
Error: Failed to open new session: java.lang.RuntimeException: java.lang.RuntimeException: org.apache.hadoop.security.AccessControlException: Permission denied: user=root, access=EXECUTE, inode="/tmp":hadoop3:supergroup:drwx------

./hadoop dfs -chmod -R 777 /tmp

第二部分 简单使用

1、查看数据库

0: jdbc:hive2://localhost:10000> show databases;
+----------------+--+
| database_name  |
+----------------+--+
| default        |
+----------------+--+
1 row selected (1.456 seconds)

2、创建并使用数据库,查看表

0: jdbc:hive2://localhost:10000> create database myhive;
No rows affected (0.576 seconds)
0: jdbc:hive2://localhost:10000> show databases;
+----------------+--+
| database_name  |
+----------------+--+
| default        |
| myhive         |
+----------------+--+
0: jdbc:hive2://localhost:10000> use myhive;
No rows affected (0.265 seconds)
0: jdbc:hive2://localhost:10000> show tables;
+-----------+--+
| tab_name  |
+-----------+--+
+-----------+--+

3、创建表

0: jdbc:hive2://localhost:10000> create table emp(id int,name string);
No rows affected (0.29 seconds)
0: jdbc:hive2://localhost:10000> show tables;
+-----------+--+
| tab_name  |
+-----------+--+
| emp       |
+-----------+--+
1 row selected (0.261 seconds)

上传数据到该目录下,从页面看的话是个目录,如下

468490-ee224a90b99af247.png
image

里面没有文件当然没有数据,那么我们需要上传个文件到该目录下。

[root@mini1 ~]# cat sz.data 
1,zhangsan
2,lisi
3,wangwu
4,furong
5,fengjie
[root@mini1 ~]# hadoop fs -put sz.data /user/hive/warehouse/myhive.db/emp

再查看

468490-1c77cc16a287ceae.png
image

4、查看表信息

0: jdbc:hive2://localhost:10000> select * from emp;
+---------+-----------+--+
| emp.id  | emp.name  |
+---------+-----------+--+
| NULL    | NULL      |
| NULL    | NULL      |
| NULL    | NULL      |
| NULL    | NULL      |
| NULL    | NULL      |
+---------+-----------+--+

结果肯定都是null,因为创建表的时候根本没指定根据”,”来切分,而文件中的字段分隔用了逗号。那么删除该表,重新上传文件,重新建表语句如下

0: jdbc:hive2://localhost:10000> drop table emp;
No rows affected (1.122 seconds)
0: jdbc:hive2://localhost:10000> show tables;
+-----------+--+
| tab_name  |
+-----------+--+
+-----------+--+
0: jdbc:hive2://localhost:10000> create table emp(id int,name string)
0: jdbc:hive2://localhost:10000> row format delimited
0: jdbc:hive2://localhost:10000> fields terminated by ',';
No rows affected (0.265 seconds)
0: jdbc:hive2://localhost:10000> 

[root@mini1 ~]# hadoop fs -put sz.data /user/hive/warehouse/myhive.db/emp
0: jdbc:hive2://localhost:10000> select * from emp;
+---------+-----------+--+
| emp.id  | emp.name  |
+---------+-----------+--+
| 1       | zhangsan  |
| 2       | lisi      |
| 3       | wangwu    |
| 4       | furong    |
| 5       | fengjie   |
+---------+-----------+--+

6、条件查询

0: jdbc:hive2://localhost:10000> select id,name from emp where id>2 order by id desc;
INFO  : Number of reduce tasks determined at compile time: 1
INFO  : In order to change the average load for a reducer (in bytes):
INFO  :   set hive.exec.reducers.bytes.per.reducer=<number>
INFO  : In order to limit the maximum number of reducers:
INFO  :   set hive.exec.reducers.max=<number>
INFO  : In order to set a constant number of reducers:
INFO  :   set mapreduce.job.reduces=<number>
INFO  : number of splits:1
INFO  : Submitting tokens for job: job_1508216103995_0004
INFO  : The url to track the job: http://mini1:8088/proxy/application_1508216103995_0004/
INFO  : Starting Job = job_1508216103995_0004, Tracking URL = http://mini1:8088/proxy/application_1508216103995_0004/
INFO  : Kill Command = /root/apps/hadoop-2.6.4/bin/hadoop job  -kill job_1508216103995_0004
INFO  : Hadoop job information for Stage-1: number of mappers: 1; number of reducers: 1
INFO  : 2017-10-18 00:35:39,865 Stage-1 map = 0%,  reduce = 0%
INFO  : 2017-10-18 00:35:46,275 Stage-1 map = 100%,  reduce = 0%, Cumulative CPU 1.33 sec
INFO  : 2017-10-18 00:35:51,487 Stage-1 map = 100%,  reduce = 100%, Cumulative CPU 2.34 sec
INFO  : MapReduce Total cumulative CPU time: 2 seconds 340 msec
INFO  : Ended Job = job_1508216103995_0004
+-----+----------+--+
| id  |   name   |
+-----+----------+--+
| 5   | fengjie  |
| 4   | furong   |
| 3   | wangwu   |
+-----+----------+--+
3 rows selected (18.96 seconds)

看到这就能明白了,写的sql最后是被解析为了mapreduce程序放到yarn上来跑的,hive其实是提供了众多的mapreduce模板。

7、创建外部表

内部表建到固定路径,外部表任意数据
与内部表的区别,删除表时候,外部创建的表所在文件夹不会被删除

0: jdbc:hive2://localhost:10000> create external table emp2(id int,name string)
0: jdbc:hive2://localhost:10000> row format delimited fields terminated by ','//指定逗号分割
0: jdbc:hive2://localhost:10000> stored as textfile//文本存储方式
0: jdbc:hive2://localhost:10000> location '/company';
No rows affected (0.101 seconds)//存储在/company目录下
0: jdbc:hive2://localhost:10000> dfs -ls /;
+----------------------------------------------------------------------------------------+--+
|                                       DFS Output                                       |
+----------------------------------------------------------------------------------------+--+
| Found 16 items                                                                         |
| -rw-r--r--   2 angelababy mygirls             7 2017-10-01 20:22 /canglaoshi_wuma.avi  |
| -rw-r--r--   2 root       supergroup         22 2017-10-03 21:12 /cangmumayi.avi       |
| drwxr-xr-x   - root       supergroup          0 2017-10-18 00:55 /company              |
| drwxr-xr-x   - root       supergroup          0 2017-10-13 04:44 /flowcount            |
| drwxr-xr-x   - root       supergroup          0 2017-10-17 03:44 /friends              |
| drwxr-xr-x   - root       supergroup          0 2017-10-17 06:19 /gc                   |
| drwxr-xr-x   - root       supergroup          0 2017-10-07 07:28 /liushishi.log        |
| -rw-r--r--   3 12706      supergroup         60 2017-10-04 21:58 /liushishi.love       |
| drwxr-xr-x   - root       supergroup          0 2017-10-17 07:32 /logenhance           |
| -rw-r--r--   2 root       supergroup         26 2017-10-16 20:49 /mapjoin              |
| drwxr-xr-x   - root       supergroup          0 2017-10-16 21:16 /mapjoincache         |
| drwxr-xr-x   - root       supergroup          0 2017-10-13 13:15 /mrjoin               |
| drwxr-xr-x   - root       supergroup          0 2017-10-16 23:35 /reverse              |
| drwx------   - root       supergroup          0 2017-10-17 13:10 /tmp                  |
| drwxr-xr-x   - root       supergroup          0 2017-10-17 13:13 /user                 |
| drwxr-xr-x   - root       supergroup          0 2017-10-14 01:33 /wordcount            |
+----------------------------------------------------------------------------------------+--+
0: jdbc:hive2://localhost:10000> create external table emp2(id int,name string)
0: jdbc:hive2://localhost:10000> row format delimited fields terminated by '\t'
0: jdbc:hive2://localhost:10000> stored as textfile
0: jdbc:hive2://localhost:10000>  location '/company';
No rows affected (0.135 seconds)
0: jdbc:hive2://localhost:10000> show tables;
+-----------+--+
| tab_name  |
+-----------+--+
| emp       |
| emp2      |
| t_sz_ext  |
+-----------+--+

能发现多了目录/company和两张表,不过这个时候/company下是没任何东西的。

8、加载文件信息到表中

前面使用了hadoop命令将文件上传到了表对应的目录下,但是也可以在命令行下直接导入文件信息

0: jdbc:hive2://localhost:10000> load data local inpath '/root/sz.data' into table emp2;(也可以用hadood直接上传,不加local就表示直接从hdfs上传文件)
INFO  : Loading data to table myhive.emp2 from file:/root/sz.data
INFO  : Table myhive.emp2 stats: [numFiles=0, totalSize=0]
No rows affected (0.414 seconds)
0: jdbc:hive2://localhost:10000> select * from emp2;
+----------+------------+--+
| emp2.id  | emp2.name  |
+----------+------------+--+
| 1        | zhangsan   |
| 2        | lisi       |
| 3        | wangwu     |
| 4        | furong     |
| 5        | fengjie    |
+----------+------------+--+

9、表分区,分区字段为school,导入数据到2个不同的分区中

0: jdbc:hive2://localhost:10000> create table stu(id int,name string)
0: jdbc:hive2://localhost:10000> partitioned by(school string)
0: jdbc:hive2://localhost:10000> row format delimited fields terminated by ',';
No rows affected (0.319 seconds)
0: jdbc:hive2://localhost:10000> show tables;
+-----------+--+
| tab_name  |
+-----------+--+
| emp       |
| emp2      |
| stu       |
| t_sz_ext  |
+-----------+--+
0: jdbc:hive2://localhost:10000> load data local inpath '/root/sz.data' into table stu partition(school='scu');
INFO  : Loading data to table myhive.stu partition (school=scu) from file:/root/sz.data
INFO  : Partition myhive.stu{school=scu} stats: [numFiles=1, numRows=0, totalSize=46, rawDataSize=0]
No rows affected (0.607 seconds)
0: jdbc:hive2://localhost:10000> select * from stu;
+---------+-----------+-------------+--+
| stu.id  | stu.name  | stu.school  |
+---------+-----------+-------------+--+
| 1       | zhangsan  | scu         |
| 2       | lisi      | scu         |
| 3       | wangwu    | scu         |
| 4       | furong    | scu         |
| 5       | fengjie   | scu         |
+---------+-----------+-------------+--+
5 rows selected (0.286 seconds)
0: jdbc:hive2://localhost:10000> load data local inpath '/root/sz2.data' into table stu partition(school='hfut');
INFO  : Loading data to table myhive.stu partition (school=hfut) from file:/root/sz2.data
INFO  : Partition myhive.stu{school=hfut} stats: [numFiles=1, numRows=0, totalSize=46, rawDataSize=0]
No rows affected (0.671 seconds)
0: jdbc:hive2://localhost:10000> select * from stu;
+---------+-----------+-------------+--+
| stu.id  | stu.name  | stu.school  |
+---------+-----------+-------------+--+
| 1       | Tom       | hfut        |
| 2       | Jack      | hfut        |
| 3       | Lucy      | hfut        |
| 4       | Kitty     | hfut        |
| 5       | Lucene    | hfut        |
| 6       | Sakura    | hfut        |
| 1       | zhangsan  | scu         |
| 2       | lisi      | scu         |
| 3       | wangwu    | scu         |
| 4       | furong    | scu         |
| 5       | fengjie   | scu         |
+---------+-----------+-------------+--+

注:hive是不遵循三范式的,别去考虑主键了。

10、添加分区

0: jdbc:hive2://localhost:10000> alter table stu add partition (school='Tokyo');

为了更直观,去页面查看

468490-425cde8a78ba219a.png
image
468490-b5f4bb059f8f12f7.png
image
468490-9152ca3dfbd65ff1.png
image

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