DML之加载和导出数据

Loading files into tables

LOAD DATA [LOCAL] INPATH 'filepath' [OVERWRITE] INTO TABLE tablename [PARTITION (partcol1=val1, partcol2=val2 ...)]
 
LOAD DATA [LOCAL] INPATH 'filepath' [OVERWRITE] INTO TABLE tablename [PARTITION (partcol1=val1, partcol2=val2 ...)] [INPUTFORMAT 'inputformat' SERDE 'serde'] (3.0 or later)

LOCAL：本地系统，如果没有写LOCAL那么就是指的是HDFS的路径
OVERWRITE：是否数据覆盖，如果没有OVERWRITE那么就是数据追加，有的话就是先删除然后再写入
LOAD DATA LOCAL INPATH ‘/home/hadoop/data/emp.txt’ OVERWRITE INTO TABLE emp;
LOAD DATA INPATH ‘hdfs://hadoop000:8020/data/emp.txt’ INTO TABLE emp;

把emp里面的内容写入emp1中，在工作中临时表用的很多
hive (default2)> create table emp1 as select * from emp;

Writing data into the filesystem from queries

INSERT OVERWRITE [LOCAL] DIRECTORY directory1
  [ROW FORMAT row_format] [STORED AS file_format] (Note: Only available starting with Hive 0.11.0)
  SELECT ... FROM ...

INSERT OVERWRITE LOCAL DIRECTORY ‘/tmp/hive/’ ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘\t’ select empno,ename,sal,deptno from emp;
ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘\t’ 以\t为分隔符

Hive不推荐使用一以下操作，因为非常消耗性能