Hazem Ben Khalfallah Hazem-Ben-Khalfallah

Software Architect by day, experimenting with code by night. 🚀 All projects here are mine—my employer has their own serious business to handle. 😎

Hazem-Ben-Khalfallah / jdk-version-compilation.java

Last active May 28, 2021 22:21

[JDK compilation version] Determine Which JDK Version a JAR/Class File Was Compiled With #java

javap -v [path to your class file] | grep 'major version'

Hazem-Ben-Khalfallah / duplicate_rows.sql

Created December 30, 2019 13:51

[Detect duplicate rows] #sql #mysql

	# display duplicate rows
	SELECT
	*
	FROM (
	SELECT
	person_id,
	@rank := IF( @email = email and @firstname = firstname, @rank + 1, 1) AS row_number,
	@email := email as email,
	@firstname := firstname as firstname
	FROM

Hazem-Ben-Khalfallah / show_constraints.sql

Last active December 30, 2019 11:49

[Show all table constraints] #sql

	SELECT TABLE_NAME,
	COLUMN_NAME,
	CONSTRAINT_NAME,
	REFERENCED_TABLE_NAME,
	REFERENCED_COLUMN_NAME
	FROM information_schema.KEY_COLUMN_USAGE
	WHERE TABLE_NAME = "<TABLE_NAME>";

Hazem-Ben-Khalfallah / ssmparameters.sh

Last active July 11, 2019 15:01

[Get ssm parameter] get all parameters from aws ssm and extract their names and descriptions #aws #ssm

aws ssm describe-parameters --query "Parameters[].{Name:Name,Description:Description}" --output text

Hazem-Ben-Khalfallah / schema.sql

Last active July 8, 2019 11:08

[DB schema and privileges] #sql #mysql

	#connect to mysql
	mysql -u root -p

	#list privileges
	select user,host from mysql.user;

	# create new schema
	CREATE SCHEMA `[SCHEMA_NAME]` DEFAULT CHARACTER SET utf8;

	# grant acess on schema to user

Hazem-Ben-Khalfallah / uuid_mysql.sql

Last active November 7, 2019 08:50

[UUID to string in Mysql] #sql #mysql

	#MySQL 8

	#convert uuid binary(16) to String
	SELECT BIN_TO_UUID(uuid) FROM foo

	#convert uuid string to binary(16)
	SELECT UUID_TO_BIN(UUID())


	#MySQL 5,6,7

Hazem-Ben-Khalfallah / disable-foreign_key_constraint.sql

Last active June 14, 2019 16:19

[Disable a foreign key constraint in MySQL] #sql #mysql

Hazem-Ben-Khalfallah / git-credentials.sh

Created May 17, 2019 10:17

[Save git credentials] I want to use a push and pull automatically without entering my user and password in a prompt, every time. #git

	# run
	git config credential.helper store
	#then
	git pull
	# user credentials will be saved in ~/.git-credentials in PLAIN text

	# if user credentials are changed in the future, simply execute
	git pull
	# and provide a new password and it will work like before.

Hazem-Ben-Khalfallah / arguments.sh

Last active January 2, 2019 15:32

[Bash args] Bash positional arguments and command line options usage #linux #bash

	#see link: http://linuxcommand.org/lc3_wss0120.php

	# Positional args
	# $#: number of items on the command line in addition to the name of the command
	# $0: name of the command


	> some_program word1 word2 word3
	# $# would be 3
	# $0 would contain "some_program"

Hazem-Ben-Khalfallah / connect-ssh.sh

Created December 26, 2018 10:50

[Connect via ssh using pem key] Connect to a remote server via #ssh using a pem key #linux

ssh -i ~/.ssh/[KEY_NAME].pem [REMOTE_USER]@[SERVER_IP_or_DNS]