Just get column names from hive table
SqlHadoopHiveSql Problem Overview
I know that you can get column names from a table via the following trick in hive:
hive> set hive.cli.print.header=true;
hive> select * from tablename;
Is it also possible to just get the column names from the table?
I dislike having to change a setting for something I only need once.
My current solution is the following:
hive> set hive.cli.print.header=true;
hive> select * from tablename;
hive> set hive.cli.print.header=false;
This seems too verbose and against the DRY-principle.
Sql Solutions
Solution 1 - Sql
If you simply want to see the column names this one line should provide it without changing any settings:
describe database.tablename;
However, if that doesn't work for your version of hive this code will provide it, but your default database will now be the database you are using:
use database;
describe tablename;
Solution 2 - Sql
you could also do show columns in $table or see https://stackoverflow.com/questions/29239565/hive-how-do-i-retrieve-all-the-databases-tables-columns/33154251#33154251 for access to hive metadata
Solution 3 - Sql
use desc tablename from Hive CLI or beeline to get all the column names. If you want the column names in a file then run the below command from the shell.
$ hive -e 'desc dbname.tablename;' > ~/columnnames.txt
where dbname is the name of the Hive database where your table is residing
You can find the file columnnames.txt in your root directory.
$cd ~
$ls
Solution 4 - Sql
The solution is
show columns in table_name;
This is simpler than use
describe tablename;
Thanks a lot.
Solution 5 - Sql
Best way to do this is setting the below property:
set hive.cli.print.header=true;
set hive.resultset.use.unique.column.names=false;