Question

I am working on my first Access 2010 database and have run into a problem editing the recordset returned from a query. This excellent blog entry details several scenarios which can result in uneditable query results. I believe my query results are not editable because my query has a Cartesian Join.

I’m not sure how to avoid this, however. The three tables involved are:

• episodes
  • Individual television episodes
  • Primary key: “episode_id”
• aridates
  • Individual airdates for a given episode
  • Primary key: “airdate_id”
  • Related to “episodes” by “airdate_episode_id”
• startdates
  • Individual download start-dates for a given episode
    • i.e. when a given episode will be available to download
  • Primary key: “startdate_id”
  • Related to “episodes” by “startdate_episode_id”

So, there is no (and I think can be no) direct relationship between airdates and startdates. However, this makes the query:

SELECT episodes.episode_id, episodes.episode_number, episodes.episode_title, airdates.airdate_region_id, airdates.airdate_date

FROM (episodes LEFT JOIN airdates ON episodes.episode_id = airdates.airdate_episode_id) LEFT JOIN startdates ON episodes.episode_id = startdates.startdate_episode_id;

return a recordset which is not editable. I need to be able to see the episode name and number along with the airdate in order to enter a startdate (episodes can not be made available for download before they have aired). So essentially, in this view I only need to be able to edit “startdates.stardate_date”.

Thanks in advance for any suggestions… a screenshot of the relationship in question can be seen here.

Answer 1

Create this query:

SELECT
    episodes.episode_id,
    episodes.episode_number,
    episodes.episode_title,
    airdates.airdate_region_id,
    airdates.airdate_date
FROM
    episodes LEFT JOIN airdates
    ON episodes.episode_id = airdates.airdate_episode_id;

Use it as the recordsource for a new form. Then create another form which uses a query of only the startdates table as its record source.

Add the second form as a subform to the first form. On the property sheet for the subform control, make the link master field episode_id and the link child field startdate_episode_id.

If you are successful, the subform will display startdates rows where the startdate_episode_id matches the episode_id of the main form’s current record. And if you add a new row in the subform, its startdate_episode_id will “inherit” the episode_id from the main form.

I emphasized control earlier because that point can be confusing. The subform control is a member of the main form’s controls collection, and the subform control contains the subform. You must find the link master/child field properties on the subform control, not the actual subform itself.