Applications Session 6 - Other Field Tyes

Other Field Types

Now that we have grasped the main parts of Access, we will progress on to look at a few of the field types that we missed out on at the beginning.

Attachment

"An attachment field type is used to Attach images, spreadsheet files, documents, charts, and other types of supported files to the records in your database, similar to attaching files to e-mail messages." In other words, an attachment field type allows you to add multiple attachments to each record in your table.

In our case study, we want to place a copy of the DVD/BluRay/Game Cover for each item in our Products table.

Step 1: Download appropriate images using google images for your movies!! There are some websites specifically for getting CD or DVD covers, but for mine, I just used Google Images and the name of the movie.

Step 2: Open your Products Table in Design View so you can add the Attachment field.

Use the insert key to insert a new field or just add it to the bottom - it really doesn't matter. I called mine Extras

Choose Attachment as the field type and Save then close your table.

Step 3: Add your images. To add your attachments - i.e. your image files, click on the paperclip image and use the dialog box to add each image to the appropriate record. You can have more than one attachment, but for our exercise, we only need one!!

Step 4: Add the field to your Products Form. Open your main products form - the one that we use to add and delete products, and add the Extras field onto the form.

Once you have added it to the form, Save and then change to Form View. Hopefully you will now see an image against each movie in your table.

Test the form - use your navigation to scroll through the movies in your table.
 
You can attach a maximum of two gigabytes of data (the maximum size for an Access database). Individual files cannot exceed 256 megabytes in size.

Lookup Field

A lookup field type will create a many to many relationship with data in another table. That probably doesn't really mean too much to you, but what it allows you to do is to have multiple values within the one field. The best way of understanding this is to see it in action.

Step 1: Start by creating a new table - I created one called Keywords. It will just have the Autonumber ID field plus a keyword field.

Click on Create and then choose Table.

Add the two fields by clicking in the column heading section of the table (or change to design view if you prefer). The field type will be short text.


Type in the Field Name of Key Words.


Then add a whole lot of  keywords - I had a bit of brain drain and couldn't really think of any, so mine are just random.

Once finished, Save the table as Keywords.

This will become our looked up table.

Step 2: Add the Lookup field to the Products table.

Open up your Products Table and change to Design View

Create a new field called keywords and select Lookup Wizard as the Data Type.

 

Follow the prompts. 

First you will be selecting a table that will be providing the values for the lookup.

Choose the fields

Pretty sure I said that you should always uncheck the Hide Key Column - well this is one occasion when it is OK to keep it hidden.

Use Keywords for the label, and importantly, put a tick next to the Allow Multiple Values.

Click Finish.

 

The Keywords field will have a field type of number when it is finished as that matches the autonumber ID field. 

Open your Movies Form again and change to Design View. Click the button to display the fields and drag your keywords field onto the form

 

Save the form and go back to Form View. Go through each record and select keywords for each movie

This field can then be used in queries.

Activity 5

Add a field to your animals table for Behaviours and temperaments.
You will also need a table to lookup Behaviours and temperaments - Call this table Traits.

• ID (Autonumber)
• Trait Description (Text)

• Create a report for all of the animals in your care - grouped by animal type

A lady rings to see if you have found any Yellow Labradors in the past week - worried sick about her beloved pet that escaped during the New Years eve fireworks. Create a query that will determine whether you have any animals matching her missing furbaby. (add some potential matches into your table to make sure that you get some items in your report)

Calculated Fields

The last of the special Access field types is Calculated Fields!! You can probably guess from the name what this means...

Rules:

    The calculation cannot include fields from other tables or queries.
    The results of the calculation are read-only.

You can also use any of the in-built Access functions

Here is an example. In our Video Vidiots database, we want to be able to keep track of how long each rental is.

To do this, we need to take the Returned date and subtract the date borrowed - this will give us the loan period in days.

Step 1: Add the calculated field to the table.

Step 2: When the expression builder window appears, put in the calculation for the field.

Click OK and make sure that you save the new table design.

Step 3: Add the field to your form. I added mine to the Rentals and the Returns Subform

Now view the form and see that the calculation works!!

Options - turning off stuff

If you were creating this for someone to use who does not know Access, you would customise it so that the user would only be able to do the things that are in your menu.

You will find all of the things that you can turn on or off in the Options for the Current Database. Turn off all of the things that you don't need as well as setting the Man Menu to be the form that displays when the database is opened.

Of course, turning off stuff also means that YOU are unable to access some of the tools that you may need to make changes to your database. To open the database so that you have all the essentials available, hold down the Shift key while double clicking the file to open it.


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Advanced Search Options - Only tackle this if you are confident

Basic Coding - Advanced Search on Form

This is optional as it does require a little bit of coding - just a taste of what you can do!! It doesn't really matter whether you understand it all, so long as you can duplicate it to suit your circumstances.

What this will enable you to do is to find the first record that matches the criteria and then click through the records that match until you find the one that you are after. This uses the principle of Find First and Find next.

Events

The use of macros and coding in Access requires you to understand what an event is - an event is anything that you can do as a user i.e. click on something, type something, load something etc. The list of available events for an item on a form are within the properties for that item.

To start with, I am going to make sure that the Headers and Footers for the form are displayed -  I want to add a search box within the form footer.

To display headers and footers, right-click on the Detail bar.

 

I minimised the Header, but increased the size of the Footer so that I could add some search boxes and button etc.

In the Footer, add 2 text boxes - they should both be unbound.

In the Properties Sheet, make sure you give them meaningful names (and remember what they are).

The Membership one is called SrchMembership
The Surname one is called SrchSurname

You will also need to add a Command Button - this will be where we will run the macro from. If this button is clicked (The EVENT), then the macro will run.

Once you have your text boxes and your command button, you are ready to type in your first bit of code. We will assume that we want to include the wildcard in the search so that it is not relying on an exact match.

Select the button and make sure that the properties sheet is displayed. Click on the drop down arrow next to On Click and select [Event Procedure]. Click on the ... button.

You will then be taken to the Visual Basic editor. Don't worry too much about it at this stage, just type in the same as you I have using the names that you have called your text boxes and fields etc.

 

Save and test your form - does it find the first record that matches your criteria? You can leave it at this, or you can add some more "Tweaks".

In my example, I have added a Find Next command Button, with the view that you can scroll through a list of "matches" until you find the one that you are looking for. The code is identical except for the FindNext instead of FindFirst. Because we have included the like and * wildcard, the match does not have to be exact - one letter is enough. The easiest way is to cut and paste the code and change the FindFirst to FindNext.

Bookmark will return the user to the current record.

Slightly More Advanced

You can add multiple buttons to search using different fields. I allowed a search on either membership number or by last name. I used a test to determine which of the fields had a value entered into it and created the search accordingly. Here is my code.