saves my old appengine datastore and replaces it with a new one

upgrade_datastore.zsh

function upgrade_datastore () {
    local ds_source="${HOME}/Dropbox/Khan Academy All Staff/Other shared items/datastores"
    local ds_target="${HOME}/projects/.gae"
    local backup_name="current.sqlite $(date "+%Y-%m-%d %H.%M.%S")"
    mv "${ds_target}/current.sqlite" "${ds_target}/${backup_name}"
    cp "${ds_source}/current.sqlite" "${ds_target}/"
    echo "Copied new current.sqlite from dropbox"
    echo "Your old current.sqlite has been archived at "
    echo "  ${fg[yellow]}${ds_target}/${backup_name}"
}