HIVE 数据操作 DML

Loading Data into Managed Tables -- 加载数据到表

LOAD DATA LOCAL INPATH '${env:HOME}/california-employees'
OVERWRITE INTO TABLE employees
PARTITION (country = 'US', state = 'CA');

LOAD DATA LOCAL ... copies  the  local data  to  the  final  location  in  the
distributed filesystem, while LOAD DATA ... (i.e., without LOCAL) moves
the data to the final location.

Inserting Data into Tables from Queries -- 加载数据从查询语句到表

INSERT OVERWRITE TABLE employees
PARTITION (country = 'US', state = 'OR')
SELECT * FROM staged_employees se
WHERE se.cnty = 'US' AND se.st = 'OR';

FROM staged_employees se
INSERT OVERWRITE TABLE employees
  PARTITION (country = 'US', state = 'OR')
  SELECT * WHERE se.cnty = 'US' AND se.st = 'OR'
INSERT OVERWRITE TABLE employees
  PARTITION (country = 'US', state = 'CA')
  SELECT * WHERE se.cnty = 'US' AND se.st = 'CA'
INSERT OVERWRITE TABLE employees
  PARTITION (country = 'US', state = 'IL')
  SELECT * WHERE se.cnty = 'US' AND se.st = 'IL';

Dynamic Partition Inserts  --动态分区

INSERT OVERWRITE TABLE employees
PARTITION (country, state)
SELECT ..., se.cnty, se.st
FROM staged_employees se;

INSERT OVERWRITE TABLE employees
PARTITION (country = 'US', state)
SELECT ..., se.cnty, se.st
FROM staged_employees se
WHERE se.cnty = 'US';

hive> set hive.exec.dynamic.partition=true;
hive> set hive.exec.dynamic.partition.mode=nonstrict;
hive> set hive.exec.max.dynamic.partitions.pernode=1000;
hive> INSERT OVERWRITE TABLE employees
    > PARTITION (country, state)
    > SELECT ..., se.cty, se.st
    > FROM staged_employees se;

Creating Tables and Loading Them in One Query --一个查询语句创建表

CREATE TABLE ca_employees
AS SELECT name, salary, address
FROM employees
WHERE se.state = 'CA';

Exporting Data --导出数据

INSERT OVERWRITE LOCAL DIRECTORY '/tmp/ca_employees'
SELECT name, salary, address
FROM employees
WHERE se.state = 'CA';

导出多个文件

FROM staged_employees se
INSERT OVERWRITE DIRECTORY '/tmp/or_employees'
  SELECT * WHERE se.cty = 'US' and se.st = 'OR'
INSERT OVERWRITE DIRECTORY '/tmp/ca_employees'
  SELECT * WHERE se.cty = 'US' and se.st = 'CA'
INSERT OVERWRITE DIRECTORY '/tmp/il_employees'
  SELECT * WHERE se.cty = 'US' and se.st = 'IL';