SQRT / Pythagoras Query problem

[gary campbell]

Hi, can someone please put me out of my misery. I have been trying to teach myself databasing (don't ask why), and have so far succeeded at a very basic level. However, I am now, and have been for weeks, stuck on this (probably) quite simple problem:

I'm using MySQL Workbench and server v.6.1

I have created several tables which feed data into the table to which this query relates - lets call it LOC. This table's columns are:

a_ID | a_name | a_address | a_X_coord | a_Y_coord | b_ID | b_Name | b_X_coord | b_Y_coord
-----------------------------------------------------------------------------

NOTE: All the coords are simple single digit X&Y's (eg X=2, Y=8), NOT geolocation coords. I'll move onto more accurate / complex geolocational problems using radians / COS etc after I've got the basics.

The problem: I'm trying to create a query that, when a user selects any 'b_Name', the query returns all the 'a' data (but not the coords) with their distances from the selected 'b' location in a table that will look like:

b_Name | a_Name | a_address | Distance_of_a_from b |
----------------------------------------------

The formula I'm using to calculate a's distance from b is pythagoras: SQRT(((a_X - b_X) * (a_X - b_X)) + ((a_Y - b_Y) * (a_Y - b_Y))) which I think is correct.


1. I've lost count of my efforts to create this query and all have returned syntax errors and no amount of tweaking rectifies it, (which leads me to believe I'm way off the mark), hence why I'm turning to the experts for help. I can post my latest failed effort if this will help.

Any help will be greatly appreciated.