Bob, Can I make the suggestion that you use 3 tables - one for the presenters, one for the presentations, and one for the topics. You may need another one but we will get to that in a minute. I am suggesting a separate table for presenters as one presenter may make a number of presentations over time and so you will not have to repeat data in the tables - one of the rules of data normalisation. Each presentation will also link to a number of topics. It is possible to setup the tables so that each presentation can link to any number of topics. The structure outlined above will waste database space if there are fewer than 3 topics assigned and will have a problem if you wish to assign more than 3 topics.
The presenters table would contain: presenterID - primary key firstname lastname any other field you wish to add regarding the presenter The presentations table would contain: presentationID - primary key date of presentation title of presentation presenterID - foreign key into the presenters table other fields relating to the presentation This sets up a one - many relationship between presenters and presentations ie one presenter can be linked to many presentations With the topics table, a suitable structure may be: topicID - primary key topic_name other fields relating to the topic The relationship between presentations and topics is not a simple one-to-many relationship. As you have described, a single presentation may be associated with many topics, and a single topic may be associated with many presentations. This is a many-to-many relationship and is best expressed via an intermediate table - presentation_topic The presentation_topic table would have the following structure presentationID topicID The two fields together form the primary key for this table. The relationship structure for the database is then as follows: The presenter table links to the presentation table via the presenterID field and the presentation table links to the topics table via the presentationID+topicID fields in the intermediate table. This structure will allow you to query the database and ask the following questions Who presented on a particular presentation How many presentations has a particular presenter made, when were these made, and what were the topics What presentations were made in a particular date range What topics were allocated to a particular presentation What presentations have been made concerning a particular topic, or number of topics. Once that data structure is in place, add some test data to see that the structure is working and you are able to retrieve the required data. Once this is successful, it is time to prepare some forms and reports so that users of the database can easily use the system. This would include drop-down lists in the forms. Mike On Thu, Dec 12, 2013 at 2:01 PM, Bob Muir <[email protected]> wrote: > I am new to databases in general and LibreOffice Base in particular. > I am using LO Version: 4.1.2.3 installed into Windows 7 Home Premium > Service Pack 1 > I want to create a database with information for about 100 presentations. > It would contain the name of the presenter, the title, and three > “keywords” or topics. > There are two tables consisting of a main table (that contains the > PresenterID, PresenterName, Date, Title, Topic1, Topic2, and Topic3) and > the table of topics for the listboxes. > I have figured out how to create a single form to fill in the data for the > two tables that uses 3 listboxes to present the choices for the topics. > > I want to make the database easily searchable for people with little > computer experience. > Is there a way to present a screen to such users with dropdown lists of > the topics (same entries as in the Topics table) that will produce a list > of the relevant presentations? > I don’t what them to have to deal with creating a query or a report. > > Am I asking for too much? > > Thanks > Bob > -- > To unsubscribe e-mail to: [email protected] > Problems? > http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ > Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette > List archive: http://listarchives.libreoffice.org/global/users/ > All messages sent to this list will be publicly archived and cannot be > deleted > -- To unsubscribe e-mail to: [email protected] Problems? http://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ Posting guidelines + more: http://wiki.documentfoundation.org/Netiquette List archive: http://listarchives.libreoffice.org/global/users/ All messages sent to this list will be publicly archived and cannot be deleted
