Office Space: Tips and Tricks for Scripting Microsoft Office Applications
Welcome to Office Space, the column that offers tips and tricks for scripting Microsoft® Office applications. We’ll post new tips every Thursday; to see an archive of previous tips, visit the Office Space Archive. And if you have particular questions about Microsoft Office scripting, feel free to send them to firstname.lastname@example.org (in English, if possible). We can’t promise to answer all the questions we receive, but we’ll do our best.
Adding New Records to and Modifying Existing Records in a Microsoft Access Database
We’ve decided to let you in on a little secret: the Scripting Guys (unlike the rest of you, of course) have their good days and their bad days. Some days we come in excited and ready to work; other days (well, OK, most days) it’s a bit different. How are you, the readers of the Office Space column, supposed to know whether you’ve hit the Scripting Guys on a good day or a bad day? Well, here’s a hint: any time the Scripting Guys decide to “expand upon a previous column” then you know they’re taking the lazy way out and not even trying to think up something new.
So what does that have to do with this week’s column? Why, nothing, nothing at all…. Since you mentioned it, though, this week we’ve decided to expand upon a previous column, one in which we showed you how to connect to and read from a Microsoft Access database. Today we’re going to take the next logical step and show you how you can add records to an Access database. And then, just for the heck of it, we’ll take another step and show you how to modify existing records as well.
OK, we admit it: we didn’t exactly knock ourselves out trying to come up with a brand-new topic for this week’s column. But we’ll rationalize that by pointing out that, as useful as it is to be able to extract data from a database, it’s just as useful (if not more so) to be able to add data to that database. So while we are being a tad bit lazy at least we’re covering an important topic. Besides, you can simply think of this as the second part in a multi-part series: you don’t have to worry that we’re just taking the easy way out!
Seeing as how we are being a tad bit lazy, we won’t review any of basic concepts behind connecting to an Access database; if you need a brief refresher on that, take a look at last week’s column. Today we’re going to get right down to business: let’s show you how to add a new record to an existing database.
To begin with, we’re assuming you have an Access database named Inventory.mdb living in the C:\Scripts folder. We’re also assuming that this database has a table named GeneralProperties, and that the GeneralProperties table includes the following fields:
Needless to say, if you don’t have such a database then none of these sample scripts will work. That doesn’t mean you can’t learn anything from them; you just won’t be able to run them and get them to do anything.
With that in mind, let’s take a look at a script that adds a new record to the database:
On Error Resume Next Const adOpenStatic = 3 Const adLockOptimistic = 3 Set objConnection = CreateObject("ADODB.Connection") Set objRecordSet = CreateObject("ADODB.Recordset") objConnection.Open _ "Provider = Microsoft.Jet.OLEDB.4.0; " & _ "Data Source = c:\scripts\inventory.mdb" objRecordSet.Open "SELECT * FROM GeneralProperties" , _ objConnection, adOpenStatic, adLockOptimistic objRecordSet.AddNew objRecordSet("ComputerName") = "atl-ws-99" objRecordSet("Department") = "Human Resources" objRecordSet("OperatingSystem") = "Microsoft Windows XP Professional" objRecordSet("Owner") = "Ken Myer" objRecordSet.Update objRecordSet.Close objConnection.Close
Note. We should note that this is not the only way to add a new record to a database. For example, SQL aficionados can also use an Insert Into query. We’re using the AddNew method simply because it’s easier; Insert Into queries can get extremely complicated, especially when you’re dealing with many fields, values stored in variables, and fields of different data types. In the lazy spirit of the day, we’re taking the easy way out.
The script starts out by connecting to the database C:\Scripts\Inventory.mdb. Like we said, we won’t discuss this in any detail, but that’s what these lines of code are for:
Const adOpenStatic = 3 Const adLockOptimistic = 3 Set objConnection = CreateObject("ADODB.Connection") Set objRecordSet = CreateObject("ADODB.Recordset") objConnection.Open _ "Provider = Microsoft.Jet.OLEDB.4.0; " & _ "Data Source = c:\scripts\inventory.mdb"
After making the connection we then use the Recordset object’s Open method to run a SQL query that retrieves all the records from the GeneralProperties table; that’s what we do here:
objRecordSet.Open "SELECT * FROM GeneralProperties" , _ objConnection, adOpenStatic, adLockOptimistic
What gives us is a recordset that we can add a new record to. And that’s what we do here:
objRecordSet.AddNew objRecordSet("ComputerName") = "atl-ws-99" objRecordSet("Department") = "Human Resources" objRecordSet("OperatingSystem") = "Microsoft Windows XP Professional" objRecordSet("Owner") = "Ken Myer" objRecordSet.Update
We begin by calling the AddNew method; this sets up a blank template to work with, but doesn’t actually add anything to the database. (At the moment, all the work we’re doing is taking place solely in memory.) We then have a series of lines that assign values to the individual fields for this new record. (These fields, of course, are the fields found in the table GeneralProperties.) For example, this line sets the value of the ComputerName field to atl-ws-99:
objRecordSet("ComputerName") = "atl-ws-99"
Note that the value being assigned (atl-ws-99) is enclosed in double quote marks; that’s because ComputerName is a text field and is expecting to be assigned a string value. If a database field is numeric or Boolean (true/false) then you should not enclose the values in double quote marks:
objRecordSet("IsLaptop") = False objRecordSet("NumberOfPrcoessors") = 2
But you knew that already, didn’t you?
Finally, we call the Update method, which actually writes the new record to the database:
Don’t forget that line of code: if you do, the recordset in memory will be updated to contain the new record, but the actual database will remain unchanged.
As you can see, adding a new record to an Access database is pretty easy. But what about modifying an existing record? For example, suppose we no sooner add the computer atl-ws-99 to the database then Ken Myer gets transferred from the Human Resources department to the Finance department. That means we now have to update the department field for that particular computer. How hard is that going to be?
Relax: it’s not going to be hard at all. Again, there are different ways to update records in a database, but for now we’ll focus on what we feel is the easiest way to update a record: you search for the record, update the appropriate field (or fields), and then call the Update method. In other words, a process that looks remarkably like this:
On Error Resume Next Const adOpenStatic = 3 Const adLockOptimistic = 3 Set objConnection = CreateObject("ADODB.Connection") Set objRecordSet = CreateObject("ADODB.Recordset") objConnection.Open _ "Provider = Microsoft.Jet.OLEDB.4.0; " & _ "Data Source = c:\scripts\inventory.mdb" objRecordSet.Open "SELECT * FROM GeneralProperties" , _ objConnection, adOpenStatic, adLockOptimistic strCriteria = "ComputerName = 'atl-ws-99'" objRecordSet.Find strCriteria objRecordset.Fields.Item("Department") = "Finance" objRecordset.Update objRecordSet.Close objConnection.Close
You probably already noticed that the first half of this script is identical to the script that adds a new record: we connect to the database, then use the Open method to return a recordset consisting of all the records in the GeneralProperties table. In fact, you won’t find any differences between the two scripts until we get to here:
strCriteria = "ComputerName = 'atl-ws-99'"
In this line of code we’re simply assigning the search criteria to a variable named strCriteria. We want to update the record for the computer named atl-ws-99; as you might expect, that becomes our search criteria, using the format FieldName = Value. Or, ComputerName = ‘atl-ws-99’.
After establishing the search criteria we call the Find method to locate that record in the recordset:
We then use these two lines of code to update the Department field and then to save the changes:
objRecordset.Fields.Item("Department") = "Finance" objRecordset.Update
Note the somewhat unusual syntax we use when referring to the Department field: objRecordset.Fields.Item(“Department”). Don’t worry too much about that; that’s just the way you have to do things. On the bright side, odd as it might look, at least it’s the same way we refer to fields when reading from a database (as we did last week).
Also, don’t overlook the Update method; once again a record will not be changed in the database until you call Update.
As we said, there are other ways we can modify existing records; however, those will have to wait for another day. Which day? Let’s put it this way: the next time we’re too lazy to think up a brand-new topic for this column, well, you can probably figure out for yourself what the topic will be.