Dearly Beloved, we are gathered here today . . . the classic opening line for marriage ceremonies. Okay, so the marriage analogy doesn’t work so well, but bringing data together is like a marriage—you are going to join two objects together and if the relationship is going to work they need to have something in common.

If we were to look at querying a table visually, our tables exist separately, and we have interacted with only one at a time.

IndividualTable

 

 

Now, lets suppose we want to join these tables.  How would we do this?  The following sections review this information.

Inner Join

Left Join

Right Join

 

 

I

Want to follow along on your own database?

Do you want to follow along with the examples?  We have created a sample database you can use to follow along and try in your own database.  Go to the download page and follow the instructions.  Have fun on the SQL trail!