How to filter “table_2” depending on the selected entry in “

Question

I'm using:

  - Entity Framework v6.2.0;

  - SQL Server 2012;

  - C#.

 

I have these tables:

 - tbl_01_Groups;

- tbl_02_Students;

- tbl_03_GroupsStud;

The tbl_01_Groups table is displayed in dataGridView1. One student can be in several groups.

To solve this problem, I suspect that it is necessary to build the table of relations tbl_03_GroupsStud.

Question: how to make dataGridView2 display table_2 records that belong to the group selected in dataGridView1?

Requirements for table_2:

 1.  table_2 should contain the following fields:

• [tbl_02_Students].[NameStud];
• [tbl_02_Students].[Property_1];
• [tbl_01_Groups].[nameGroup];
• ... other columns as needed

2. if changes are made in the table_2 record, then these changes are displayed in the original source;

3. if an entry is added to the table_2, then this entry is displayed in the source;

Table_2 is planned to be used in another query.

 

How to make the table_2 meet the above requirements?

Something like I managed to do with the help of queries in MSAccess:

Request req_GroupsStud_Stud:

SELECT tbl_03_GroupsStud.*, tbl_02_Students.NameStud
FROM tbl_03_GroupsStud
INNER JOIN tbl_02_Students
ON tbl_03_GroupsStud.id_stud = tbl_02_Students.id_stud;

Request req_GroupsStud_CurGroup: 

SELECT req_GroupsStud_Stud.*, req_GroupsStud_Stud.id_group
FROM req_GroupsStud_Stud
WHERE (((req_GroupsStud_Stud.id_group)=[Forms]![frm_00_00_MainForm]![id_group_Frm]));

From the form, using the expression [Forms]![Frm_00_00_MainForm]![Id_group_Frm], the parameter [id_group_Frm] is passed to the request.

I don’t understand how to do the same thing using the entity-framework and MS SQL Serever.

 

 

 

My code

ContextDB cntxtDB;

public Frm1UC()
{
    InitializeComponent();

    cntxtDB = new ContextDB();
}

private void Frm1UC_Load(object sender, EventArgs e)
{
    Fill_dataGridView1();
}

public void Fill_dataGridView1()
{
    try
    {
        cntxtDB.tbl_01_Groups.Load();
        bs_Grid1.DataSource = cntxtDB.tbl_01_Groups.Local.ToBindingList();
        dataGridView1.DataSource = bs_Grid1;
    }
    catch (Exception ex)
    {
        string s = ex.Message;
        string t = ex.StackTrace;
        // throw;
        MessageBox.Show(s);
    }
}