Data from ListBox to DataSet - delphi

Question

I have DBGrid where I load names from DataSetPeople associated to table_people. I create a Drag and Drop procedure, where the user can drag a name and drop into a ListBox. The user can drop into a listbox_employees or listbox_manager.
MY PROBLEM
I want to create a relationship between people from table_people using the names that user drop in both listbox. I create table_relationship where employeeID match with managerID.
So, how can I get the name from each listbox, associate this name to an ID, and put this ID into a employeeID or managerID from DataSetRelationship associated to table_relationship ?

Answer 1

If your IDs are numeric (integer) values, you can use the TListBox.Items.Objects to store it when you fill it (in your drop event handler on the form):
var
PersonName: string;
PersonID: Integer;
begin
with YourDataModule do // Gives access to the tables in the data module
begin
PersonName := table_people.FieldByName('employeeName').AsString;
PersonID := table_people.FieldByName('employeeID').AsInteger);
end;
listbox_employees.Items.AddObject(PersonName, TObject(PersonID);
end;
For the manager, just change to the listbox for the manager and the field values for the manager.
To get the ID back out to use for an INSERT statement:
// Make sure both listboxes have the same number of items, of course.
var
EmployeeID: Integer;
ManagerID: Integer;
i: Integer;
begin
for i := 0 to ListBox_Employees.Items.Count - 1 do
begin
EmployeeID := Integer(ListBox_Employees.Items.Objects[i]);
ManagerID := Integer(ListBox_Manager.Items.Objects[i]);
if not YourDataModule.MakeRelationship(EmployeeID, ManagerID) then
ShowMessage('Unable to relate this employee and manager!');
end;
end;
// If you're using a SQL query, the `INSERT` should be created like this
// somewhere, like in your datamodule's OnCreate event
// qryRelationShips.SQL.Clear;
// qryRelationShips.SQL.Add('INSERT INTO table_relationship (employeeID, managerID)');
// qryRelationShips.SQL.Add('VALUES (:employeeID, :managerID)';
//
// Or you can type it into the SQL property in the Object Inspector at designtime
// INSERT INTO table_relationship (employeeID, managerID) VALUES (:employeeID, :managerID)
function TYourDataModule.MakeRelationship(const EmpID, MgrID: Integer): Boolean;
begin
Result := False;
// INSERT into your dataset:
qryRelationShips.ParamByName('employeeID').AsInteger := EmpID;
qryRelationShips.ParamByName('managerID').AsInteger := MgrID;
try
qryRelationShips.ExecSQL;
Result := qryRelationShips.RowsAffected;
finally
qryRelationShips.Close;
end;
end;
// If you're using a table instead of a query, getting a result is harder
function TYourDataModule.MakeRelationship(const EmpID, MgrID: Integer): Boolean;
begin
Result := True;
try
tblRelationShips.Insert;
tblRelationShips.FieldByName('employeeID').AsInteger := EmpID;
tblRelationShips.FieldByName('managerID').AsInteger := MgrID;
tblRelationShips.Post;
except
Result := False;
end;
end;

Answer 2

I hope you have made tables using SQLite database. So what you want to do is possible by using a query to insert the rows. Use db.execSQL();
You can keep a counter for incrementong the id values.