HBase--Shell

2016-06-23

HBase

HBase help
其他命令
举个例子

　　有段时间没更新了，今天就来个简单的吧–HBase的Shell。这个没什么技术含量，主要是帮助文档太强大了！可以说无需刻意记忆，help command就搞定了。那为什么还要写这篇博客呢？那就回到了第一句话“有段时间没更新了”来个简单的(●’◡’●)”！其实，不是啦，主要是用来提醒自己两件事情，一多看帮助文档和源码，二不要忽视简单的东西脚踏实地。（注：HBase版本0.98.8-hadoop2）

HBase help

进入Shell

[root@xxo07 ~]# hbase shell
HBase Shell; enter 'help<RETURN>' for list of supported commands.
Type "exit<RETURN>" to leave the HBase Shell
Version 0.98.8-hadoop2, r6cfc8d064754251365e070a10a82eb169956d5fe, Fri Nov 14 18:26:29 PST 2014

HBase help

hbase(main):001:0> hbase help
HBase Shell, version 0.98.8-hadoop2, r6cfc8d064754251365e070a10axxo6d5fe, Fri Nov 14 18:26:29 PST 2014
Type 'help "COMMAND"', (e.g. 'help "get"' -- the quotes are necessary) for help on a specific command.
Commands are grouped. Type 'help "COMMAND_GROUP"', (e.g. 'help "general"') for help on a command group.

################################## Shell 分组了，便于记忆 ########################################
COMMAND GROUPS:
  Group name: general  ##普通命令
  Commands: status, table_help, version, whoami

  Group name: ddl    ##数据定义语言（data definition language） 不用解释 重点掌握
  Commands: alter, alter_async, alter_status, create, describe, disable, disable_all, drop, drop_all, 
   enable, enable_all, exists, get_table, is_disabled, is_enabled, list, show_filters

  Group name: namespace  ##这个命令空间命令相对table命令用的少，给table命令让步了然他加了后缀
  Commands: alter_namespace, create_namespace, describe_namespace, drop_namespace, list_namespace, 
   list_namespace_tables

  Group name: dml   ##数据操作语言（Data Manipulation Language 不用解释 重点掌握
  Commands: append,count,delete,deleteall,get,get_counter,incr,put,scan,truncate,truncate_preserve

  Group name: tools ##一般很少用，一旦用上久的细心点
  Commands: assign, balance_switch, balancer, catalogjanitor_enabled, catalogjanitor_run, 
   catalogjanitor_switch, close_region, compact, compact_rs, flush, hlog_roll, major_compact, 
   merge_region, move, split, trace, unassign, zk_dump

  Group name: replication ##备份操作命
  Commands: add_peer, disable_peer, enable_peer, list_peers, list_replicated_tables, remove_peer, 
    set_peer_tableCFs, show_peer_tableCFs

  Group name: snapshots ##快照，和元数据相关 0.95之后默认开启snapshot功能，之前版本的需要手动开启
  Commands: clone_snapshot,delete_snapshot,list_snapshots,rename_snapshot,restore_snapshot,snapshot

  Group name: security  ##授权
  Commands: grant, revoke, user_permission

  Group name: visibility labels ##可见性标签操作命令
  Commands: add_labels, clear_auths, get_auths, set_auths, set_visibility

################################# Shell 用法 #########################################
SHELL USAGE:
Quote all names in HBase Shell such as table and column names.  Commas delimit
command parameters.  Type <RETURN> after entering a command to run it.
Dictionaries of configuration used in the creation and alteration of tables are
Ruby Hashes. They look like this:

  {'key1' => 'value1', 'key2' => 'value2', ...}

and are opened and closed with curley-braces.  Key/values are delimited by the
'=>' character combination.  Usually keys are predefined constants such as
NAME, VERSIONS, COMPRESSION, etc.  Constants do not need to be quoted.  Type
'Object.constants' to see a (messy) list of all constants in the environment.

If you are using binary keys or values and need to enter them in the shell, use
double-quote'd hexadecimal representation. For example:

  hbase> get 't1', "key\x03\x3f\xcd"
  hbase> get 't1', "key\003\023\011"
  hbase> put 't1', "test\xef\xff", 'f1:', "\x01\x33\x40"

The HBase shell is the (J)Ruby IRB with the above HBase-specific commands added.
For more on the HBase Shell, see http://hbase.apache.org/book.html
NoMethodError: undefined method `hbase' for #<Object:0x2b6b35f4>

其他命令

其他就不在这里一一举例了，比如想查看careat的用法直接“ help 'create' ” 就 ok,如下图：

举个例子

以用户表user为例，如下图：

行键 row_key ： uid(倒置) ;
列族 column_famliy : nm和Info
限定符(列族Info的限定符 ) ： flos(关注) | fans(粉丝) | fw(鲜花)
表结构：如下

操作

创建一个具有两个列族“nm”和“info”的表“user”，注意单引号和逗号。
hbase(main):001:0> create ‘user’,’nm’,’info’
list，查看当前 HBase 中具有哪些表。
hbase(main):012:0> list
describe 查看表构造。
hbase(main):003:0> describe ‘user’
Table user is ENABLED
COLUMN FAMILIES DESCRIPTION
{NAME => ‘info’, DATA_BLOCK_ENCODING => ‘NONE’, BLOOMFILTER => ‘ROW’, REPLICATION_SCOPE => ‘
0’, VERSIONS => ‘1’, COMPRESSION => ‘NONE’, MIN_VERSIONS => ‘0’, TTL => ‘FOREVER’, KEEP_DELE
TED_CELLS => ‘FALSE’, BLOCKSIZE => ‘65536’, IN_MEMORY => ‘false’, BLOCKCACHE => ‘true’}
{NAME => ‘nm’, DATA_BLOCK_ENCODING => ‘NONE’, BLOOMFILTER => ‘ROW’, REPLICATION_SCOPE => ‘0’
, VERSIONS => ‘1’, COMPRESSION => ‘NONE’, MIN_VERSIONS => ‘0’, TTL => ‘FOREVER’, KEEP_DELETE
D_CELLS => ‘FALSE’, BLOCKSIZE => ‘65536’, IN_MEMORY => ‘false’, BLOCKCACHE => ‘true’}
2 row(s) in 0.0750 seconds
put 命令向表中插入数据,参数分别为表名、行名、列名和值
a. 加入数据,第一行键为“25”,列族“nm”,值为 xiaoxiao。第二行略
hbase(main):006:0> put ‘user’,’25’,’nm’,’xiaoxiao’
hbase(main):007:0> put ‘user’,’71’,’nm’,’momo’
hbase(main):010:0> put ‘user’,’25’,’info:flos’,’52’
get 查询
hbase(main):010:0> get ‘user’,’71’
COLUMN CELL
nm: timestamp=1466829836778, value=momo
hbase(main):011:0> get ‘user’,’25’,’info:flos’
COLUMN CELL
info:flos timestamp=1466830066408, value=52
scan 查询，这个比较强大
hbase(main):012:0> scan ‘user’
ROW COLUMN+CELL
25 column=info:flos, timestamp=1466830066408, value=52
25 column=nm:, timestamp=1466829764632, value=xiaoxiao
71 column=nm:, timestamp=1466829836778, value=momo
count 统计行数
hbase(main):015:0> count ‘user’
2 row(s) in 0.0530 seconds
=> 2
delete 删除某条数据
hbase(main):028:0> delete ‘user’,’72’,’info:fans’
truncate 清空数据，谨慎使用
hbase(main):029:0> truncate ‘user’
drop 删除表，drop之前需要disbale table
hbase(main):030:0> disable ‘user’
hbase(main):032:0> drop ‘user’
status 查看状态
hbase(main):033:0> status
1 servers, 0 dead, 4.0000 average load
version 查看版本
hbase(main):032:0> version
0.98.8-hadoop2, r6cfc8d064754251365e070a10a82eb169956d5fe, Fri Nov 14 18:26:29 PST 2014
exit 退出
hbase(main):033:0> exit

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