Complex MySQL Query - Radius Search - Linking Tables

OK so I have been developing this website in which I list businesses for sale. And I've been working on a radius search feature. my database looks as follows. I have 2 tables.

First table 'businesses'
Fields:

businessName
businessAddress
businessCity
businessZip


Second Table I have a list of all us Cities / Zips / Lat Long
Fields:

id
zip_code
city
county
state_name
state_prefix
lat
long


now I've managed to use the code made by Barand do do distance calculations

SELECT * FROM cities
WHERE
    60 * 1.1515 * DEGREES(ACOS(SIN(RADIANS($cityXlat))
    * SIN(RADIANS(latitude)) +  COS(RADIANS($cityXlat))
    * COS(RADIANS(latitude)) * COS(RADIANS($cityXlong-longitude)))) <= 50

Code (markup):

However, I only want to return results in the table 'businesses'. I'm assuming I have to link the tables, I was figuring by zip. But how would I construct the query to not only link the tables but only return results that exist in the table businesses within the specified range?

 

i think a normal inner left join will do...

SELECT t1.*,t2.* FROM businesses AS t1 LEFT JOIN cities AS t2 ON t1.businessZip = t2.zip_code
WHERE
60 * 1.1515 * DEGREES(ACOS(SIN(RADIANS($cityXlat))
* SIN(RADIANS(t2.latitude)) + COS(RADIANS($cityXlat))
* COS(RADIANS(t2.latitude)) * COS(RADIANS($cityXlong-t2.longitude)))) <= 50

 

an inner join would be better, you already have ALL cities and you only want what is in business
Left joins are bad (well not good )