Learn Microsoft Access Advanced Programming Techniques, Tips and Tricks.

Friday, April 20, 2007

modifying data

Modifying Data

Modifying data is a bit more complicated because the script must make certain that the appropriate record is in fact available, in other words, that it exists and is not locked by a security setting or other transaction. So this example uses three scripts. The first, amend_select.asp, generates an HTML form listing the available categories from the Categories table. It passes your selection to the second, amend_change.asp, which creates a new form displaying the selected record's current values as editable fields. Those are submitted to the third script, amend.asp, which updates the actual database record accordingly with the new values.

To try these scripts out, install the files and call up the following URL:http://localhost/sample/amend_select.asp

It should display a simple drop-down control, a <select></select> element named ProdCats with an <option></option> for each CategoryName in the categories table. Select a category and click the Submit button.

This will execute amend_change.asp, which uses the submitted ProdCats to build a SQL query and generate a new form with the appropriate record's CategoryID, CategoryName, and Description values. Modify the name and description and click Change to send the new values to amend.asp. That script will construct and execute a SQL UPDATE statement from the new values. If successful, it returns the confirmation message: You have successfully amended a record.

Opening the Categories table in access should reveal your changes.

Note that the second template, amend_change.asp, puts the CategoryID in a hidden input named txtID. We need to pass the CategoryID value to amend.asp in order to uniquely identify the record, but because it is an AutoNumber field, we don't want the user to modify it. By using a hidden input, the field is passed along, but the user never sees or changes it. This is the standard way to include a record's unique, automatically generated identifier in an HTML form.

Click Next for Deleting-data

  1. Installing the Personal Web Server (PWS)
  2. or Internet Information Services (IIS)
  3. Create the Example ASP Files
  4. Create a DSN Connection
  5. Connect to the Database
  6. Modify Access Data Online
  7. Inserting Data
  8. Modifying Data
  9. Deleting Data
  10. Data Insert Form

No comments:

Post a Comment

Comments subject to moderation before publishing.

Powered by Blogger.