Create a Country Database in MySql for chained select drop down box.

I need a chained drop down box to be built for selecting users in a COUNTRY based on (1) State (2) District (3) City/Town and (4) Pin/Zip code (Location based). For the above i need a MySql DB. The whole world is to be mapped in a MySql Database on the above lines. They are interlinked in the sense that if i select a particular country in the FIRST drop down box then all the states in that country should populate in the next drop down box. After i select one or all the states in this SECOND drop down box then the corresponding Districts should populate the THIRD drop down box and so on so forth till Pin/Zip code. You are NOT required to code the webpage for the above job. You only need to create the MySql Database for the above project. If you know how to code the select drop down box for the above project too then it will be an added capacity to get recruited for the job in the future (not in this project but the next one).