function onOpen(){
var form = FormApp.openById('239jelkwpeowppd-3843ikeifd89wered');

var conn = mySQL();
var itemList = getEmpList(conn);

var item = form.getTitle('Approver:');
item.setChoiceValues(itemList);
}

function getEmpList(conn){
var sql = conn.createStatement();
var ds = sql.executeQuery('SELECT empNAME FROM emp');
var columns = ds.getMetaData().getColumnCount();
var list=[];
while (ds.next()) {
var rowString = '';
for (var col = 0; col < columns; col++) {
rowString += ds.getString(col + 1) + 't';
list.push(rowString);
}
}
return list;
}

function mySQL(){
var dbConn = Jdbc.getConnection("jdbc:mysql://dbURL","user","password");
return dbConn;
}