Jun Yin injune1123

I hereby claim:

To claim this, I am signing this object:

	sudo su - postgres

	create database #{DATABASE_NAME};


	psql -U postgres

	//list all dbs
	postgres-# \l

	Learning resources:
	https://learngitbranching.js.org/

	I stashed twice, what shall I do????!!!!
	https://www.atlassian.com/git/tutorials/saving-changes/git-stash

	$git stash list
	$git stash apply stash@{n}

	Switching remote URLs

	//check the version of JAVA
	java -version

	// Switch to JAVA 8 on macOS High Sierra and Mojave
	$export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_161.jdk/Contents/Home/