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    <p>As @marc_s said using <strong>Database managed keys</strong> is more viable. But in cases there is no much load on the database, for example because there are few users who work simultanously, I will use another easier method. That's I get the last id, I try to add new record, and if I encountered error for duplicate, I will try again. I limited this to 3 trials for my application and there's a 300 ms timeout between each trial. <em>Dont forget that this approach has <strong>serious limitations</strong></em>. In my application, there are very <em>few users</em>, the work load is <em>very low</em>, and the connection is a <em>local</em> one so this will do job well. Perhaps in other applications you need to adjust the delay, and in some cases, the approach <strong>might completely fail</strong>. Here's the code, I have two tables, <code>Invoices</code> and <code>Invoices_Items</code> the column which relates them is <code>invoice_id</code>:</p> <pre><code> byte attempts = 0; tryagain: //Find last invoice no OleDbCommand command = new OleDbCommand("SELECT MAX(invoice_id) FROM Invoices" , myconnection); int last_invoice_id = 0; try { last_invoice_id = (int)command.ExecuteScalar(); } catch (InvalidCastException) { }; // text_invoice_number.Text = Convert.ToString(last_invoice_id + 1); try { command = new OleDbCommand(@"INSERT INTO Invoices (invoice_id,patient_id,visit_id,issue_date,invoice_to,doctor_id,assistant_id) VALUES(?,?,?,?,?,?,?)",myconnection); // We use last_invoice_id+1 as primary key command.Parameters.AddWithValue("@invoice_id",last_invoice_id+1); // I will add other parameters here (with the exact order in query) command.ExecuteNonQuery(); } catch (Exception ex){ attempts++; if (attempts &lt;= 3) // 3 attempts { System.Threading.Thread.Sleep(300); // 300 ms second delay goto tryagain; } else { MessageBox.Show("Can not add invoice to database, " + ex.Message, "Unexpected error!" , MessageBoxButtons.OK, MessageBoxIcon.Error); return; } } for (int i = 0; i &lt;= listInvoiceItems.Count-1; i++) { command = new OleDbCommand(@"INSERT INTO Invoices_Items (invoice_id,quantity,product,price,amount,item_type) VALUES(?,?,?,?,?,?)",myconnection); // Now we use our stored last_invoice_id+1 as foreign key command.Parameters.AddWithValue("@invoice_id",last_invoice_id+1); // Add other Invoice Items parameters here (with the exact order in query) command.ExecuteNonQuery(); } </code></pre>
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    1. PODifferent ways to generate the latest int type primary foreign key in code
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    1. USehsan88
    1. USehsan88
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    1. COcant there be a way in which we pass a temporary id from the code and the temp ids are converted to the actual id in query or db
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    2. CO@puneet I don't understand your question.
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    3. COCan I assign some temporary ids in the code and when saving those temporary ids convert to the actual ones in script or something.
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