SELECT `email` FROM `intern` INNER JOIN `extern` ON `intern`.`md5` = `extern`.`md5` and reading the 2 csv and compare it in 2 loops. Sublime Text - How to Compare Two Files Almost every database requires CSV files to back up the data. Now you have both files containing a column with a notation for any values that appear in the other file. CSV Comparator is a tool for comparing files which contain CSV-Data. JavaScript Compare two CSV files Compares CSV files, applying some rules. Compare Two Files How to merge multiple csv files in to one file - Medium Comparing two objects or .csv files column by column To use it open your project files by pressing command + o ( CTRL on Windows) and opening the directory containing your project files. For example, we have the following array: let arrayHeader = ["Name","Country","Email"]; let arrayData [] = ["Sigit Prasetya","Indonesia","sigit@gmail.com"]; arrayData [] = ["Song Hye Kyo","South Korea","songsong@gmail.com"]; arrayData [] = ["Andy Lau","Hongkong","andyLau@gmail.