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The following page has been changed by udanax: http://wiki.apache.org/lucene-hadoop/Hbase/HbaseShell ------------------------------------------------------------------------------ ||Delete ||'''Delete''' command deletes specified rows in table. [[BR]][[BR]]~-''DELETE { column_name, [, column_name] ... | COLUMNFAMILIES(column_family[, column_family] ... | *} [[BR]]{{{ }}}FROM table_name[[BR]]{{{ }}}[WHERE row = 'row-key'];''-~ || ||Select ||<99%>'''Select''' command retrieves rows from a table.[[BR]][[BR]]~-''SELECT { column_name [, column_name] ... | * }[[BR]]{{{ }}}FROM table_name[[BR]]{{{ }}}[WHERE row = 'row-key' | STARTING FROM 'row-key'][[BR]]{{{ }}}[NUM_VERSIONS = version_count][[BR]]{{{ }}}[TIMESTAMP 'timestamp'][[BR]]{{{ }}}[LIMIT = row_count][[BR]]{{{ }}}[INTO FILE 'file_name'][[BR]][[BR]]''-~'''column_name:'''~-''[[BR]]{{{ }}}column_family_name[[BR]]{{{ }}}| column_family_name:column_label_name''-~ || + = Examples = + == Example Of Basic Query Command Uses == + === Create the table in a Hbase === + + {{{ + hql > help create; + CREATE Create tables + + Syntax: + CREATE TABLE table_name + column_family_definition [, column_family_definition] ... + + column_family_definition: + column_family_name + [MAX_VERSIONS=n] + [MAX_LENGTH=n] + [COMPRESSION=NONE|RECORD|BLOCK] + [IN_MEMORY] + [BLOOMFILTER=NONE|BLOOMFILTER|COUNTING_BLOOMFILTER|RETOUCHED_BLOOMFILTER VECTOR_SIZE=n NUM_HASH=n] + }}} + + '''CREATE TABLE''' enables you to create a new table with various options for each column family. + + * ~-'''MAX_VERSIONS''' makes a table keep only the recent n versions in a cell. Its default value is 3, i.e., only the most recent 3 versions of values are stored in a cell.-~ + * ~-'''MAX_LENGTH''' specifies the maximum size of a column value. By default, the maximum size is unlimited. It is limited only by Integer.MAX_VALUE.-~ + * ~-'''COMPRESSION''' specifies which compression technique to use for the column family. By default, Hbase does not compress any data.-~ + * ~-'''IN_MEMORY''' specifies whether to keep the values in the column family in-memory, or not. By default, values are not kept in-memory.-~ + * ~-'''BLOOMFILTER''' specifies which bloom filter to use for the column family. By default, none of the bloom filters is used. You can specify the options in two ways: with '''VECTOR_SIZE''' and '''NUM_HASH''', or with '''NUM_ENTRIES'''. '''VECTOR_SIZE''' specifies the number of elements in the vector, and '''NUM_HASH''' specifies the number of hash functions to use; With '''NUM_ENTRIES''', you specify only the approximated number of entries in the column, and '''VECTOR_SIZE''' and '''NUM_HASH''' are automatically determined.-~ + + {{{ + hql > CREATE TABLE movieLog_table ( + --> year, length, inColor, studioName, vote, producer, actor) + --> NUM_VERSIONS 10; + + hql > CREATE TABLE webtable ( + --> contents in_memory max_versions=10 compression=block, + --> anchor max_length=256 bloomfilter=counting_bloomfilter + --> vector_size=1000000 num_hash=4); + }}} + + === Select data from a table === + {{{ + hql > help select; + SELECT Select values from tables + + Syntax: + SELECT { column_name, [, column_name] ... | *} FROM table_name + [WHERE row='row_key' | STARTING FROM 'row-key'] + [NUM_VERSIONS = version_count] + [TIMESTAMP 'timestamp'] + [LIMIT = row_count] + [INTO FILE 'file_name'] + }}} + + '''SELECT''' retrieves a subset of data from the specified table. + + * ~-'''STARTING FROM''' returns all the rows starting from 'row-key'.-~ + * ~-'''NUM_VERSIONS''' retrieves only the recent n versions of values in a cell.-~ + * ~-'''TIMESTAMP''' returns only the values with the specified timestamp.-~ + * ~-'''LIMIT''' limits the number of rows to be returned.-~ + + {{{ + hql > SELECT studioName: FROM movieLog_table WHERE row = 'Star Wars'; + + +---------------------------------------------+ + | title studioName | + | =========================================== | + | Star Wars Fox Entertainment Group, Inc. | + +---------------------------------------------+ + + Successfully print out the selected data.(0.05 sec) + + hql > SELECT 'studioName:YoungGu Art, Corp.' FROM movieLog_table WHERE row = 'D-War'; + }}} + + === Insert data into a table === + {{{ + hql > help insert; + INSERT Insert values into tables + + Syntax: + INSERT INTO table_name + (colmn_name, ...) VALUES ('value', ...) + WHERE row='row_key' + + column_name: + column_family_name + | column_family_name:column_label_name + }}} + + '''INSERT''' inserts a set of values into a table. + + * ~-If the specified column already exists, the new value is stored as a new version.-~ + * ~-If '''TIMESTAMP''' is not specified for the value, the current time is used as its timestamp.-~ + + {{{ + hql > INSERT INTO movieLog_table (year:, length:, inColor:, studioName:, 'vote:user name', producer:, 'actor:hero') + --> VALUES ('1977', '124', 'true', 'Fox', '5', 'George Lucas', 'Mark Hamill') + --> WHERE row='Star Wars'; + }}} + + === Delete data in a table === + {{{ + hql > help delete; + DELETE Delete table data + + Syntax: + DELETE { column_name, [, column_name] ... | COLUMNFAMILIES(column_family[, column_family] ... | *} + FROM table_name + [WHERE row = 'row-key']; + }}} + + * Asterisk (*) will be delete the all in table. + * COLUMNFAMILIES(column_family list) will be delete the all columns in columnfamily. + * Specified column_name will be delete the specified column data. + + {{{ + hql > DELETE actor:hero FROM movieLog_table; + hql > DELETE actor:hero FROM movieLog_table WHERE row='Star Wars'; + hql > DELETE * FROM movieLog_table; + }}} + + === How to use external jars in Hbase Shell === + + {{{ + hql > HELP JAR; + JAR jarFile [mainClass] args...; + ... + + hql > JAR ./build/hadoop-examples.jar pi 10 10; + }}} +
