Hive 6Hive DML(Data Manipulation Language)
Posted tesla-turing
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了Hive 6Hive DML(Data Manipulation Language)相关的知识,希望对你有一定的参考价值。
DML主要是对Hive 表中的数据进行操作的(增 删 改),但是由于Hadoop的特性,所以单条的修改、删除,其性能会非常的低所以不支持进行级操作;
主要说明一下最常用的批量插入数据较为常用的方法:
1、从文件中加载数据
语法:LOAD DATA [LOCAL] INPATH ‘filepath‘ [OVERWRITE] INTO TABLE tablename [PARTITION (partcol1=val1, partcol2=val2 ...)]
例:
load data local inpath ‘/opt/data.txt‘ overwrite into table table1; -- 如果文件存放在HDFS中,则不需要写Local
语法:Standard syntax: INSERT OVERWRITE TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...) [IF NOT EXISTS]] select_statement1 FROM from_statement; INSERT INTO TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...)] select_statement1 FROM from_statement; Hive extension (multiple inserts): FROM from_statement INSERT OVERWRITE TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...) [IF NOT EXISTS]] select_statement1 [INSERT OVERWRITE TABLE tablename2 [PARTITION ... [IF NOT EXISTS]] select_statement2] [INSERT INTO TABLE tablename2 [PARTITION ...] select_statement2] ...; FROM from_statement INSERT INTO TABLE tablename1 [PARTITION (partcol1=val1, partcol2=val2 ...)] select_statement1 [INSERT INTO TABLE tablename2 [PARTITION ...] select_statement2] [INSERT OVERWRITE TABLE tablename2 [PARTITION ... [IF NOT EXISTS]] select_statement2] ...; Hive extension (dynamic partition inserts): INSERT OVERWRITE TABLE tablename PARTITION (partcol1[=val1], partcol2[=val2] ...) select_statement FROM from_statement; INSERT INTO TABLE tablename PARTITION (partcol1[=val1], partcol2[=val2] ...) select_statement FROM from_statement;
FROM page_view_stg pvs INSERT OVERWRITE TABLE page_view PARTITION(dt=‘2008-06-08‘, country) SELECT pvs.viewTime, pvs.userid, pvs.page_url, pvs.referrer_url, null, null, pvs.ip, pvs.cnt
以上是关于Hive 6Hive DML(Data Manipulation Language)的主要内容,如果未能解决你的问题,请参考以下文章