Building Contact Detail Maintenance into a Mailing List Program with Borland Delphi

Building Contact Detail Maintenance into a Mailing List Program with Borland Delphi
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Add two more forms to the project and save the units as new_contact and addresses. On the new contacts form, drop three edits (rename them edname, edemail and ednewgroup), two radio buttons (rename them rb1 and rb2), two statictext (name and email), two buttons (rename to btnAddContact and btnCancel) and a combobox (rename to cb). This is how the form should look:

On the form's onshow event, add the following code:

procedure TForm2.FormShow(Sender: TObject);
begin
 cb.Visible:=false;
 ednewgroup.Visible:=false;
end;

Because we only take the contact's name and email address, the form provides us with text fields that will take that information. The next step is to decide whether you want to add this contact to a group. To make the choices clearer, I've added two radio buttons, one asking if you want to add the new contact to a group and the other if you want to create a new group. You can choose one or the other but not both.

If you choose to add the contact to a group, a drop down box with the various group names in it will  appear. All you have to do is click on that name and then click on the "Add Contact" button. Below is the code for the Add Contact button:

procedure TForm2.btnAddContactClick(Sender: TObject);
var
gname:string;
new_id:integer;
grpid,newgrp:boolean;
begin
new_id:=0;
if (edname.text = '') or (edemail.Text = '') then begin
showmessage('Please enter a name and email address');
exit;
end;
//purpose: to get the groupID of the selected groupname
if rb1.Checked then begin
 if cb.Text <> '' then begin
 gname:=cb.Text;
//search for the groupID of the selected groupname 
 form1.query1.Close;
 form1.query1.SQL.Text:='SELECT groupID from groups WHERE
groupname=:thename';
 form1.query1.Parameters.ParamByName('thename').Value:=gname;
 form1.query1.Open;
//Check if the group id is greater than 0:
  if form1.query1.FieldByName('groupID').AsInteger > 0  then
  begin
  new_id:= form1.query1.FieldByName('groupID').AsInteger;
  grpid:=true;
  //Now insert the data into the database
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO contacts (name,email,gid)
values (:aname,:aemail,:agid)';
  form1.query1.Parameters.ParamByName('aname').Value:=edname.Text;
  form1.query1.Parameters.ParamByName('aemail').Value:=edemail.text;
  form1.query1.Parameters.ParamByName('agid').Value:=new_id;
  form1.query1.ExecSQL;
  showmessage('New contact has been added');
    end
  else
  begin
  //the record with the selected name has not been found, set the
groupID to zero
  new_id:=0;
  //Now insert the data into the database
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO contacts (name,email,gid)
values (:aname,:aemail,:agid)';
  form1.query1.Parameters.ParamByName
('aname').Value:=edname.Text;
  form1.query1.Parameters.ParamByName
('aemail').Value:=edemail.text;
  form1.query1.Parameters.ParamByName('agid').Value:=new_id;
  form1.query1.ExecSQL;
  showmessage('New contact has been added');
  grpid:=false;
  end;
  end
  else
  begin
//User did not select a name...
  showmessage('Please select a group name to add the new contact
to.'+#13#10+ 'If you do not see the group name on the list then
create a new group name by selecting the ''Create a New Group ''
option below.');
  exit;
  end;
  end;//end main IF
  if rb2.Checked then
  begin
//check that the new name is entered
  if ednewgroup.Text <> '' then begin
//add the new groupname to the groups table and get its ID
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO groups (groupname) values
(:edval)';
  form1.query1.Parameters.ParamByName('edval').Value:=ednewgroup.Text;
  form1.query1.ExecSQL;
  //now get the group id
  form1.query1.close;
  form1.query1.SQL.Text:='SELECT groupID from groups WHERE
groupname=:thename';
  form1.query1.Parameters.ParamByName
('thename').Value:=form2.ednewgroup.Text;
  form1.query1.Open;
  new_id:=form1.query1.fieldbyname('groupID').AsInteger;
  //insert the new groupname..
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO contacts (name,email,gid)
values (:aname,:aemail,:agid)';
  form1.query1.Parameters.ParamByName
('aname').Value:=edname.Text;
  form1.query1.Parameters.ParamByName
('aemail').Value:=edemail.text;
  form1.query1.Parameters.ParamByName('agid').Value:=new_id;
  form1.query1.ExecSQL;
  showmessage('Both the new group: '+ednewgroup.Text+ ' and
contact: '+inttostr(new_id)+' has been added.');
  end
  else
  begin
  showmessage('Please enter a groupname.');
  exit;
  end;
  end;
  if not (rb1.Checked) and not (rb2.Checked) then
  begin
  form1.query1.Close;
  form1.query1.SQL.Text:='INSERT INTO contacts (name,email,gid)
values (:aname,:aemail,:agid)';
  form1.query1.Parameters.ParamByName
('aname').Value:=edname.Text;
  form1.query1.Parameters.ParamByName
('aemail').Value:=edemail.text;
  form1.query1.Parameters.ParamByName('agid').Value:=0;
  form1.query1.ExecSQL;
  showmessage('New contact has been added.');
  end;
  end;

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