标签：from col 方法 性能 strong lang 文件中 path dfs
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：
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
Hive 6、Hive DML(Data Manipulation Language)
标签：from col 方法 性能 strong lang 文件中 path dfs
原文地址：https://www.cnblogs.com/tesla-turing/p/11509271.html
