The title pretty much says it all, but to elaborate: If I build a mySQL database on my local dev machine, populate it with data, and subsequently want to migrate the database to a shared host (in this case, Siteground,) how do I do so in a way that keeps structure and data intact?
In this case, I don't have file access to the database server.
use mysqldump (doc) and dump your database (mysqldump [databasename] for a simple configuration) on your development machine to a dump (a file containing sql statements needed to recover both schema and data). Now insert the dump on your shared-host using the provided utilities (normaly you get phpMyAdmin preinstalled from your hoster, which can import dumps)
In addition to the response made by theomega (namely, do a dump of your development database and then insert the dump into your production database), be aware that you may need to enable large SQL insert statements if you have a lot of data. I would recommend you first FTP the file to the host, and then do the insert from a file. Each host has their own way of doing it, but if you can connect to the remote server using SSH, there is likely the ability to run the insert using the command line.
also in addition to theomega: most tools for mysql has dump / execute functions for sql files.
if you're using navicat, for an example, you're just a right-click away:
right-click on the database you want to export, and choose "dump sql file". this will allow you to save the .sql file on your local drive in the folder of your choosing.
then, right click on the destination database and choose "execute batch file". browse to the newly-created .sql file and it will execute all sql commands from that file in the destination database. namely, creating a copy of the exported db.