| 知乎专栏 ｜ 多维度架构 |
如果你又任何一种关系型数据库的使用经验，那么你将在这里看到非常熟悉的操作。
CREATE TABLE member (name string, age int, sex int);
hive> CREATE TABLE member (name string, age int, sex int); OK Time taken: 0.687 seconds hive>
基于现有的数据建表
hive> create table newtable as select * from oldtable;
hive> SHOW TABLES; OK test Time taken: 0.041 seconds, Fetched: 1 row(s) hive>
通配符匹配表名称
show tables '*t*';
hive> CREATE TABLE member (name string, age int, sex int); OK Time taken: 0.273 seconds hive> desc member; OK name string age int sex int Time taken: 0.035 seconds, Fetched: 3 row(s) hive>
增加一个字段 phone 字符串类型
hive> ALTER TABLE member ADD COLUMNS (phone String); OK Time taken: 0.188 seconds hive> desc member; OK name string age int sex int phone string Time taken: 0.033 seconds, Fetched: 4 row(s)
将 test 表重命名为 vipuser
hive> CREATE TABLE test (name string, age int, sex int); OK Time taken: 0.311 seconds hive> ALTER TABLE test RENAME TO vipuser; OK Time taken: 0.115 seconds hive> desc vipuser; OK name string age int sex int Time taken: 0.032 seconds, Fetched: 3 row(s) hive>
hive> SHOW PARTITIONS passwd; OK computer=hadoop computer=hbase computer=hive Time taken: 0.056 seconds, Fetched: 3 row(s)
hive> CREATE TABLE passwd (a string, b string, c string, d string, e string, f string) PARTITIONED BY (computer string) ROW FORMAT DELIMITED FIELDS TERMINATED BY ':'; OK Time taken: 0.323 seconds hive> load data local inpath '/etc/passwd' overwrite into table passwd partition(computer="hive"); Loading data to table default.passwd partition (computer=hive) OK Time taken: 0.499 seconds hive> select * from passwd; OK root x 0 0 root /root hive bin x 1 1 bin /bin hive daemon x 2 2 daemon /sbin hive adm x 3 4 adm /var/adm hive lp x 4 7 lp /var/spool/lpd hive sync x 5 0 sync /sbin hive shutdown x 6 0 shutdown /sbin hive halt x 7 0 halt /sbin hive mail x 8 12 mail /var/spool/mail hive operator x 11 0 operator /root hive games x 12 100 games /usr/games hive ftp x 14 50 FTP User /var/ftp hive nobody x 99 99 Nobody / hive dbus x 81 81 System message bus / hive polkitd x 999 998 User for polkitd / hive avahi x 70 70 Avahi mDNS/DNS-SD Stack /var/run/avahi-daemon hive avahi-autoipd x 170 170 Avahi IPv4LL Stack /var/lib/avahi-autoipd hive postfix x 89 89 /var/spool/postfix hive sshd x 74 74 Privilege-separated SSH /var/empty/sshd hive ntp x 38 38 /etc/ntp hive rpc x 32 32 Rpcbind Daemon /var/lib/rpcbind hive qemu x 107 107 qemu user / hive unbound x 998 996 Unbound DNS resolver /etc/unbound hive rpcuser x 29 29 RPC Service User /var/lib/nfs hive nfsnobody x 65534 65534 Anonymous NFS User /var/lib/nfs hive saslauth x 997 76 "Saslauthd user" /run/saslauthd hive radvd x 75 75 radvd user / hive nagios x 1000 1000 /home/nagios hive apache x 48 48 Apache /usr/share/httpd hive exim x 93 93 /var/spool/exim hive tss x 59 59 Account used by the trousers package to sandbox the tcsd daemon /dev/null hive git x 996 994 /var/opt/gitlab hive gitlab-www x 995 993 /var/opt/gitlab/nginx hive gitlab-redis x 994 992 /var/opt/gitlab/redis hive gitlab-psql x 993 991 /var/opt/gitlab/postgresql hive nginx x 992 990 nginx user /var/cache/nginx hive www x 80 80 Web Application /www hive mysql x 27 27 MySQL Server /var/lib/mysql hive redis x 991 989 Redis Database Server /var/lib/redis hive epmd x 990 988 Erlang Port Mapper Daemon /tmp hive rabbitmq x 989 987 RabbitMQ messaging server /var/lib/rabbitmq hive solr x 1001 1001 Apache Solr /srv/solr hive mongodb x 184 986 MongoDB Database Server /var/lib/mongodb hive test x 1002 1002 /home/test hive sysaccount x 988 985 /home/sysaccount hive systemd-bus-proxy x 987 983 systemd Bus Proxy / hive systemd-network x 986 982 systemd Network Management / hive elasticsearch x 985 980 elasticsearch user /home/elasticsearch hive zabbix x 984 979 Zabbix Monitoring System /var/lib/zabbix hive mysqlrouter x 983 978 MySQL Router /var/lib/mysqlrouter hive hadoop x 1003 1003 /home/hadoop hive Time taken: 0.118 seconds, Fetched: 51 row(s) hive> SHOW PARTITIONS passwd; OK computer=hive Time taken: 0.058 seconds, Fetched: 1 row(s)
hive> CREATE VIEW v_test AS SELECT name,age FROM member where age>20; hive> select * from v_test;
首先创建一个文本文件，如下：
[root@localhost ~]# cat /tmp/hive.txt 1 2 3 2 3 4 3 4 5 6 7 8
hive> CREATE TABLE test (a int, b int, c int) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t'; OK Time taken: 0.294 seconds hive> LOAD DATA LOCAL INPATH '/tmp/hive.txt' OVERWRITE INTO TABLE test; Loading data to table default.test OK Time taken: 0.541 seconds hive> select * from test; OK 1 2 3 2 3 4 3 4 5 6 7 8 Time taken: 0.952 seconds, Fetched: 5 row(s)
[hadoop@localhost ~]$ hdfs dfs -ls /user/hive/warehouse Found 3 items drwxrwxr-x - hadoop supergroup 0 2017-06-29 03:36 /user/hive/warehouse/member drwxrwxr-x - hadoop supergroup 0 2017-06-29 03:32 /user/hive/warehouse/test drwxrwxr-x - hadoop supergroup 0 2017-06-29 03:41 /user/hive/warehouse/vipuser [hadoop@localhost ~]$ hdfs dfs -cp /user/hive/warehouse/vipuser /user/hive/warehouse/vipuser2
hive> INSERT OVERWRITE LOCAL DIRECTORY '/tmp/test' SELECT * FROM test; hive> INSERT OVERWRITE LOCAL DIRECTORY '/tmp/test' SELECT * FROM member; 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 = hadoop_20170629040540_ddeda146-efed-44c4-bb20-a6453c21cc8e 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_1498716998098_0001, Tracking URL = http://localhost:8088/proxy/application_1498716998098_0001/ Kill Command = /srv/apache-hadoop/bin/hadoop job -kill job_1498716998098_0001 Hadoop job information for Stage-1: number of mappers: 0; number of reducers: 0 2017-06-29 04:05:49,221 Stage-1 map = 0%, reduce = 0% Ended Job = job_1498716998098_0001 Moving data to local directory /tmp/test MapReduce Jobs Launched: Stage-Stage-1: HDFS Read: 0 HDFS Write: 0 SUCCESS Total MapReduce CPU Time Spent: 0 msec OK Time taken: 10.54 seconds