Using Delphi with MySQL - Form Two
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There are two buttons on form2. The first button inserts a new article and the second button is used to update an article.
Add the following code to the first button:
procedure TForm2.BitBtn1Click(Sender: TObject);
begin
form1.q1.close;
form1.q1.SQL.Text:='INSERT INTO articles (auth,title,article_body,date_published) values
('''+edit1.text+''','''+edit2.Text+''','''+memo1.lines.
Text+''','''+edit3.text+''')';
form1.q1.ExecSQL;
showmessage('New record inserted.');
end;
The code is straightforward. It runs a query that inserts a new article based on the values entered into the form components.
Add the following code to the second button:
procedure TForm2.Button1Click(Sender: TObject);
begin
form1.q1.close;
form1.q1.SQL.Text:='UPDATE articles SET
auth=:aname,title=:atitle,article_body=:sbody,date_published=
:apubdate WHERE aid=:Aid';
form1.q1.Parameters.ParamByName('aname').Value:=edit1.text;
form1.q1.Parameters.ParamByName('atitle').Value:=edit2.text;
form1.q1.Parameters.ParamByName('sbody').Value:=memo1.Lines.Text;
form1.q1.Parameters.ParamByName('apubdate').Value:=edit3.text;
form1.q1.Parameters.ParamByName('Aid').Value:=id;
form1.q1.ExecSQL;
showmessage('All Updated.');
end;
This code is straightforward as well. It only updates the article sent over from form one and sends the updated version back to the database. The important thing here is the "aid" value in the "where" clause of the query. It identifies the article that you want changed. If you don't include a where clause, every article in the database will be overwritten with the values that you intended only for this article. Below is a test run of the application:
Conclusion
This is just a simple example intended to demonstrate how to connect and interact with a MYSQL database. It is not as easy as when creating a single user database, but it gives your applications a lot more performance power. It also makes it possible for you to write thin client applications that can be used on a large network. That is something you cannot do with a single user database.
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