Gossamer Forum: Products: Gossamer Links: Development, Plugins and Globals: SQL Index problems

I am trying to duplicate 3 fields that currently exist in their own table, and add them to lsql_Links Table.
I have added the columns, but I am having difficulty with the indexes.

The table I am trying to dup has this for indexes...

When I run this SQL code using a separate table named 'lsql_ZipCodes', it works fine(via phpMyAdmin)

Code:
SELECT o.ZipCode, o.State,   

    (3956 * (2 * ASIN(SQRT(   

        POWER(SIN(((z.Latitude-o.Latitude)*0.017453293)/2),2) +   

        COS(z.Latitude*0.017453293) *   

        COS(o.Latitude*0.017453293) *   

        POWER(SIN(((z.Longitude-o.Longitude)*0.017453293)/2),2)   

    )))) AS Distance   

FROM lsql_ZipCodes z,   

    lsql_ZipCodes o,   

    lsql_ZipCodes a   

WHERE z.ZipCode = 54720  AND   

    z.ZipCode = a.ZipCode AND   

    (3956 * (2 * ASIN(SQRT(   

        POWER(SIN(((z.Latitude-o.Latitude)*0.017453293)/2),2) +   

        COS(z.Latitude*0.017453293) *   

        COS(o.Latitude*0.017453293) *   

        POWER(SIN(((z.Longitude-o.Longitude)*0.017453293)/2),2)   

    )))) <= 50   

ORDER BY Distance

The output gives me...

PERFECT... So, now I have added Zip, Longitude and Latitude to lsql_Links table.
I have modified the SQL code to this (diffs in red). I essentially just changed lsql_ZipCodes to lsql_Links (Also, my column is called Zip, not ZipCode)

Code:
SELECT o.Zip, o.State,   

    (3956 * (2 * ASIN(SQRT(   

        POWER(SIN(((z.Latitude-o.Latitude)*0.017453293)/2),2) +   

        COS(z.Latitude*0.017453293) *   

        COS(o.Latitude*0.017453293) *   

        POWER(SIN(((z.Longitude-o.Longitude)*0.017453293)/2),2)   

    )))) AS Distance   

FROM lsql_Links z,   

lsql_Links o,   

lsql_Links a   

WHERE z.Zip = 54720  AND   

    z.Zip = a.Zip AND   

    (3956 * (2 * ASIN(SQRT(   

        POWER(SIN(((z.Latitude-o.Latitude)*0.017453293)/2),2) +   

        COS(z.Latitude*0.017453293) *   

        COS(o.Latitude*0.017453293) *   

        POWER(SIN(((z.Longitude-o.Longitude)*0.017453293)/2),2)   

    )))) <= 50   

ORDER BY Distance

The output gives me...

Note that I do not have "Distance", and the results are just wrong.

The only thing I can find that is different between the separate table 'lsql_ZipCodes' and 'lsql_links' is the indexes.
lsql_ZipCodes indexes are shown above (1st pic).

For lsql_Links indexes I currently have this ( I do not want to loose PRIMARY key of ID) and screw up the Links table

So... if I click on "Explain SQL" after running the 1st query above (the working one with the separate table lsql_ZipCodes), it shows me the following

When I click on "Explain SQL" with the second query (the messed up one using lsql_Links), it shows me this

So... :-)
This seems to be an index issue and I am wondering if someone can steer me in the right direction

Thanks
Chris
RGB World, Inc. - Software & Web Development.
rgbworld.com