Mysql join and aliasing with mysql_fetch_object()

I'm using a query similar to: select tableA.*, tableB.* from tableA, left join tableB ON tableA.keyfield = tableB.keyfield When I then try to access the column "keyfield", after using mysql_fetch_object() e.g. $resultObject->keyfield I get no value returned. What is the correct way to reference a field/column that has the same name (as it's a primary and foreign key) on both tables? Is there some syntax like: $resultObject->tableA.keyfield ? I've tried specifically aliasing the field on tableA e.g. select tableA.*, tableA.keyfield AS myKeyField, tableB.* from tableA, left join tableB ON tableA.keyfield = tableB.keyfield and then using $resultObject->myKeyField but that doesn't seem to work either. I can't find any useful info/examples about this on the PHP site. Also if I change the query to be: select tableA.*, tableB.* from tableA, tableB left join tableB ON tableA.keyfield = tableB.keyfield adding the joined table to the FROM clause I get an error. Surely this is the correct syntax and if anything my initial syntax should fail! Am I not understanding this correctly or is my mySQL manual out of sync? Please help Thanks