Using Delphi with ADO - Practical Example with Data Aware Components
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Drop an ADOTdotable component from the ADO tab (rename to ado1), then go to the Data Access tab and drop a datasource component. Once you've done that, go to the Data Controls tab and drop DBGrid and DBNavigator (rename to dbnav) components.
Now make the following connections:
Select the datasource component, go to the object inspectors properties tab, then go to the Data Set property on the drop-down list. You should see ado1; select it.
Select the ado1 component and go to its connection string property. Click on the ellipses button and a screen should come up that looks like this:
Click on build. A screen that looks like this should pop up:
Select Jet 4 OLE DB and click next. A screen that looks like this should pop up:
Click on the ellipses button on option number 1. Go to where you've stored the database that you've downloaded from this article. Click OK, then OK again.
Now, click on the DBGrid component and select its data source property. In the drop down list, you should see datasource1 as an item on that list. Select it.
Finally, select the dbnav component and on its datasource property, select datasource1.
At this point your form should look something like this:
Now we are done with the component connection. We now need to select a table from the database that we want to work with. Our database has only one table called person, so go to the TableName property of the ADOTable component and select "person."
You can view the contents of the database in design time simply by setting the active property of the ADOTable to true. The same thing is done at run time to view the contents:
Have a look at the table contents at design time:
As you can see, it is very easy to view the contents of a table when using ADO with Data Aware components, both at design time and run time, all without writing a single line of code! To change the data in the table, simply double click on the line that you want to change and change the data.
To actually work with the data, as in changing, adding and deleting records, we are going to use the database navigation component. This component makes it easy for us to add, remove and change database content:
In ADO, when you (for example) want to change a record, the table is set in edit mode, and after you've made your changes, you need to post those changes to the database. Posting changes is the same as saving the changes you make in a document. In fact you need to post any changes that you make to the database, so that the database can refresh and reflect the changes you made.
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