title: Comparing Excel tables and keep matching information in data.frame R
body: <p>I have recently restarted to use R, and I'm trying to compare two excel tables (let's call them table 1 and 2), with very different data. The only common point is situated in one column (let's name it col1), and is the gene ID. 
  My goal is to find and keep all the rows of table 1 in which the data in col1 is exactly matching the data in table2.</p>
  
  <p>For example if table1 contains 10 columns and col1 contains geneID. Table2 contains only 5 columns and col2 contains geneID. I want to compare and keep matching information of those two columns and get a data.frame containing the whole rows of table1 that I want to keep.</p>
  
  <p>I hope I'm clear? English is not my first language ^^
  Thanks a lot !</p>