vb net-database with two tables ,retrieving records - database

Question

my question is the following:
i have 2 tables created in access and created a form in vb net.
The first table consists of: Id(primary key),first name,lastname.
thes second table contains the visits and it consists of:visitID,DateOfVisit.
My question is how to join these two tables so that each ID fron the first table when selected to display the correspodind row from the second table..
For example one ID can have surname and lastname and 1 or more dates that are stored in the second table..
When i search for name it fills only the firstname and the lastname but not the date.This is where i have stuck.I want when i search with the name to also fill the correspoding textbox or display in a grid the dates that the selected record has.
Thanks.

Answer 1

Imports System.Data.OleDb
Public Class Form1
Dim provider As String
Dim dataFile As String
Dim connString As String
Public myConnection As OleDbConnection = New OleDbConnection
Public dr As OleDbDataReader
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'DoctorDataSet.Table1' table. You can move, or remove it, as needed.
Me.Table1TableAdapter.Fill(Me.DoctorDataSet.Table1)
provider = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source ="
dataFile = "C:\Users\Desktop\Desktop\doctor.accdb" ' Change it to your Access Database location
connString = provider & dataFile
myConnection.ConnectionString = connString
End Sub
Private Sub FindButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles FindButton.Click
myConnection.Open()
FirstnameTextBox.Clear()
LastnameTextBox.Clear()
VisitsTextBox.Clear()
Dim str As String
str = "SELECT * FROM table1 WHERE (Firstname = '" & CodeText.Text & "')"
Dim cmd As OleDbCommand = New OleDbCommand(str, myConnection)
dr = cmd.ExecuteReader
While dr.Read()
FirstnameTextBox.Text = dr("Firstname").ToString
LastnameTextBox.Text = dr("Lastname").ToString
VisitsTextBox.Text = dr("Visits").ToString
End While
myConnection.Close()
End Sub
Private Sub Table1BindingNavigatorSaveItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Table1BindingNavigatorSaveItem.Click
Me.Validate()
Me.Table1BindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.DoctorDataSet)
End Sub
Private Sub BindingNavigatorMovePreviousItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BindingNavigatorMovePreviousItem.Click
End Sub
End Class
I attach the full code as well as the database and a screenshot from the prgoramm.everything works well when i search,but as you can see i have also one more table(table2) which contains the number of appointments for each id from table1.Thats where i have stuck,i cant get this to work ..for example id from table1 apart from the info for name and surnames to also display and the number of visits.
I hope i am more clear now..:)
ps: i am new in vbnet and only started a few days ago programming in that language.

Answer 2

Ok just forget what i wrote i will try to put it in another way...
These are my 2 tables:
Table1 for customers,first column is for the id of each one which is unique,then the firstname and second name follow.
ID Firstname SecondName
1 John Jones
2 James Jameson
3 Nick Patrick
4 Nicky Summers
Table2 is for storing the date of visit.Each ID from table1 can have 0 or more visits.In that case only the third(Nick Patrick) in null.
ID Visit_Date
1 1/1/2010
2 5/1/2012
3 -
4 7/1/2014
I have created the database in access and load it on my project in visual studio.When I drag and drop the boxes from my datasource from the right column into the form I have one textbox for id,one for firstname,one for secondname and one for visitdate.
The navigation bar is placed on the top.when I press the next button all the fields are filled apart from the visit_date textbox which displays the first record always.

Answer 3

This should be the answer to your problem.
You can't join the 2 tables unless they both have a common field. So your 2nd table should have an ID field too and should not be a primary key. Then you can use this SQL statement.
"SELECT table1.ID, table1.firstname, table1.lastname, table2.visitID, table2.dateofvisit FROM table1 INNER JOIN table2 ON table1.ID=table2.ID WHERE table1.ID='" & ID & "'"
where ID is the variable name which holds the ID of a person. You shouldn't be using the FirstName field for the WHERE clause since it is possible that people have the same first names. Use the unique field among all the fields...which in this case is the ID field.