كيف أقوم بجمع هذين الحقلين

السلام عليكم ورحمة الله وبركاته

الحمد لله وفقنى الله لإيجاد الحل

وأصبحت الجملة كالتالى

SELECT invoices.inv_number, [EMPLOYEES].[emp_firstname]+' '+[EMPLOYEES].[emp_lastname] AS DocName, [PATIENT_DETAILS].[patient_firstname]+' '+[PATIENT_DETAILS].[patient_mi]+' '+[PATIENT_DETAILS].[patient_lastname] AS PatName, inv_amounts.inv_amount, invoices.inv_discount, ([inv_amounts].[inv_amount]-(([inv_amounts].[inv_amount]*[invoices].[inv_discount])/100)) AS NetFees, Sum(inv_payments.inv_pay_pat) AS SumOfinv_pay_pat, Sum(inv_payments.inv_pay_ins) AS SumOfinv_pay_ins, invoices.inv_id, Sum((([inv_amounts].[inv_amount]-(([inv_amounts].[inv_amount]*[invoices].[inv_discount])/100))-([inv_payments].[inv_pay_pat]+[inv_payments].[inv_pay_ins]))) AS Balance, invoices.inv_date, invoices.inv_notes, invoices.inv_modeid, invoices.inv_madeby, [EMPLOYEES].[emp_firstname]+' '+[EMPLOYEES].[emp_lastname] AS empname, invoices.inv_insid
FROM (((invoices LEFT JOIN inv_payments ON invoices.inv_id = inv_payments.inv_id) INNER JOIN EMPLOYEES ON invoices.inv_doctorid = EMPLOYEES.empId) INNER JOIN PATIENT_DETAILS ON invoices.inv_patientid = PATIENT_DETAILS.patientId) INNER JOIN inv_amounts ON invoices.inv_id = inv_amounts.inv_id
GROUP BY invoices.inv_number, [EMPLOYEES].[emp_firstname]+' '+[EMPLOYEES].[emp_lastname], [PATIENT_DETAILS].[patient_firstname]+' '+[PATIENT_DETAILS].[patient_mi]+' '+[PATIENT_DETAILS].[patient_lastname], inv_amounts.inv_amount, invoices.inv_discount, ([inv_amounts].[inv_amount]-(([inv_amounts].[inv_amount]*[invoices].[inv_discount])/100)), invoices.inv_id, invoices.inv_date, invoices.inv_notes, invoices.inv_modeid, invoices.inv_madeby, [EMPLOYEES].[emp_firstname]+' '+[EMPLOYEES].[emp_lastname], invoices.inv_insid