database field is empty while using audit plugin for MySQL 5.6.21 community editoin

I am using server_audit.so for auditing MySQL data into audit file everything is working as expected however database field is coming as empty in the audit log. Here is the sample information

Here is the sequence of events I fired on mySQL server
1. connected to server
2. executed show databases
3. change the database context using USE command, it is not captured

20170120 01:12:26,mariadbserver1,root,localhost,1,0,CONNECT,,,0
20170120 01:34:24,mariadbserver1,root,localhost,1,9,QUERY,,'show databases',0
20170120 01:34:27,mariadbserver1,root,localhost,1,10,QUERY,,'SELECT DATABASE()',0
20170120 01:34:30,mariadbserver1,root,localhost,1,11,QUERY,,'show tables',0
20170120 01:34:39,mariadbserver1,root,localhost,1,12,QUERY,,'delete from user where id=2',0
20170120 01:34:45,mariadbserver1,root,localhost,1,13,QUERY,,'delete from user where id=3',0