Today, we will see how to query the hbase using apache drill sql interface. Apache drill provides ANSI SQL language for query data from any data source. We will use it to query hbase.
If you don’t have hbase and apache drill on your machine, then follow the below link before going further.
Now lets start
1) Run apache drill shell “bin/sqlline -u jdbc:drill:zk=local”
2) Open WEB UI to enable MongoDB driver, URL of web UI is “http://localhost:8047”
3) Now click on storage link
4) In storage , find hbase and click on update
5) Add the following info in the textbox
6) Then click Update button to enable this driver
7) On apache drill shell, run “show databases;“, this will also display the hbase databases too.
8) Now lets query clicks table, “select * from hbase.clicks;“, it will display all clicks information.
9) You need to cast hbase column to varchar to see its correct values, like
“SELECT CAST(clicks.row_key as VarChar(20)), CAST(clicks.clickinfo.studentid as VarChar(20)), CAST (clicks.clickinfo.url as VarChar(20)), CAST (clicks.iteminfo.quantity as VarChar(20)), CAST (clicks.iteminfo.itemtype as VarChar(20)) FROM hbase.clicks;”
10) Now lets join students and clicks table
select cast(s.account.name as varchar(20)) as name, cast(c.clickinfo.url as varchar(100)) as url from hbase.students as s
join hbase.clicks as c
on cast(s.row_key as varchar(20)) = cast(c.clickinfo.studentid as varchar(20));