zeppelin interpreter error even after giving correct details - apache

Question

getting the below error
and i have given mysql settings in the interpreter:
com.mysql.jdbc.Driver
jdbc:mysql://:3306/
username and password
restarted interpreter and binded it, but still get the error
using commands: use and select commands
enter code herejava.lang.NullPointerException
at org.apache.zeppelin.postgresql.PostgreSqlInterpreter.executeSql(PostgreSqlInterpreter.java:201)
at org.apache.zeppelin.postgresql.PostgreSqlInterpreter.interpret(PostgreSqlInterpreter.java:288)
at org.apache.zeppelin.interpreter.ClassloaderInterpreter.interpret(ClassloaderInterpreter.java:57)
at org.apache.zeppelin.interpreter.LazyOpenInterpreter.interpret(LazyOpenInterpreter.java:93)
at org.apache.zeppelin.interpreter.remote.RemoteInterpreterServer$InterpretJob.jobRun(RemoteInterpreterServer.java:300)
at org.apache.zeppelin.scheduler.Job.run(Job.java:169)
at org.apache.zeppelin.scheduler.FIFOScheduler$1.run(FIFOScheduler.java:134)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
at java.util.concurrent.FutureTask.run(FutureTask.java:166)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:178)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:292)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

Answer 1

Adding the jar to $ZEPPELIN_HOME/lib folder like user3921855 didn't work for me.
I got it working adding MYSQL connector to dependency section in the interpreter config (ex: Artifact : mysql:mysql-connector-java:5.1.38)
IMPORTANT :
You need to restart Zeppelin daemon for the interpreter to pick the new jar. Don't know why because it said it had restarted the sub-process. Might be a bug.
Stop / Start Reminder :
$ZEPPELIN_HOME/bin/zeppelin-daemon.sh stop
$ZEPPELIN_HOME/bin/zeppelin-daemon.sh start