I. HBase Shell Operation

1.1 Basic Operations

• Enter HBase Client

  [kino@hadoop102 hbase]$ bin/hbase shell
  

  After entering the client, backspace is the character after deleting the cursor, and ctrl + backspace is the character before deleting the cursor.
• View Help Command

  hbase(main):001:0> help
  

  hbase(main):001:0> command help
  

• See which tables are in the current database

  hbase(main):001:0> list
  

1.2 Table Operation

• Create table

  # Create a table with a namespace of ns1, named t1, column family of f1, and five versions of the current column family
  hbase(main):002:0> hbase> create 'ns1:t1', {NAME => 'f1', VERSIONS => 5}
  

  # Create a table named t1 with a namespace default and specify three column families f1, f2, and f3, respectively
  hbase(main):002:0> create 't1', {NAME => 'f1'}, {NAME => 'f2'}, {NAME => 'f3'}
  
  # Above is abbreviated as follows
  hbase(main):002:0> create 't1', 'f1', 'f2', 'f3'
  

• View all tables

  hbase(main):002:0> list
  

• Insert data into tables

  # Insert data into t1 table with ns1 namespace, row_key with r1, column family with c1 and value
  hbase(main):002:0> put 'ns1:t1', 'r1', 'c1', 'value'
  
  # For example:
  hbase(main):002:0> put 'student','1001','info:name','kino'
  

• Scanning View Table Data

  # View all data in the t1 table in the namespace
  hbase(main):002:0> scan 'ns1:t1'
  
  # View the data of the specified column family in the t1 table in the namespace
  hbase(main):002:0> scan 'ns1:t1', {COLUMNS => ['c1', 'c2'], LIMIT => 10, STARTROW => 'xyz'}
  
  # View the row_key in the t1 table in the namespace from STARTROW (included) to STOPROW (not included)
  hbase(main):002:0> scan 'ns1:t1', {STARTROW => '1001', STOPROW  => '1001'}
  
  # View the t1 table in the namespace, specifying n historical versions of column family n1
  hbase(main):002:0> scan 'ns1:t1', {RAW => true, VERSIONS => 10}
  

• View data for a specified row or column family

  hbase(main):002:0> get 'ns1:t1','r1'
  	
  hbase(main):002:0> get 'ns1:t1','r1','c1'
  

• View table structure

  hbase(main):002:0> describe 'ns1:b1'
  

• Update data for specified fields

  hbase(main):002:0> put 'ns1:t1', 'r1', 'c1', 'value'
  	
  # For example: 
  hbase(main):002:0> put 'student','1001','info:name','Nick'
  

• Number of rows in statistical tables

  hbase(main):002:0> count 'student'
  

• Delete data

  • Delete all row_key data

    hbase(main):002:0> deleteall 'ns1:t1', 'r1'
    

  • Delete a column of row_key data

    hbase(main):002:0> delete 'ns1:t1', 'r1', 'c1'
    

• Empty table data
  The order of operation for emptying the table is disable first, then truncate.

  hbase(main):002:0> truncate 'ns1:t1'
  

• Delete table
  The table is enabled by default. To delete it, disable the table before deleting it.
  If you drop the table directly, an error will be reported: ERROR: Table student is enabled. Disable it first.

  hbase(main):002:0> disable 'ns1:t1'
  	
  	
  hbase(main):002:0> drop 'ns1:t1'
  

• Change table information
  Store the data in the info column family in three versions:

  hbase(main):002:0> alter 'ns1:t1',{NAME=>'info',VERSIONS=>3}