Basic commands in Hive Query Language
Following are the Basic commands in Hive Query Language which will help you in using Hive effectively:
- Command to create a databse
create database < Database Name >;
- Listing the available databases
show databases;
- Creating tables
create table XYZ( XYZ int, XYZ string, XYZ string) row format delimited fields terminated by ',';
- To enter the data using a csv file copy it in the warehouse directory of hive using
$ hdfs dfs -put record.csv /user/hive/warehouse/XYZ
And then type this in hive shell
LOAD DATA LOCAL INPATH '/home/cloudera/input.txt' INTO TABLE XYZ;
- Display table
select * from XYZ;
- Describe table
describe XYZ;
OR
describe extended XYZ;
- We can make various types of tables like":
a. External - it helps in storing the data at an external location
b. Managed - it is managed inside the hive warehouse
c. Temporary - it is managed tempoararily for a session
External:
create external table XYZ_external(XYZ int, XYZ string, XYZ string) row format delimited fields terminated by ',' LOCATION '/hive_demo/';
Managed:
create table XYZ_Managed(XYZ int,XYZ string,XYZ string) partitioned by (branch string) clustered by (section) into 2 buckets row format delimited fields terminated by ',';
Temporary:
create temporary table XYZ(XYZ int,XYZ String);
For more better understanding of HiveQL visit this Github repository [LINK] (https://github.com/OpenGenus/hive_guide)