1 files changed, 10 insertions, 0 deletions
diff --git a/invoice/service.go b/invoice/service.go
index 099f6a0..3dcc5e2 100644
--- a/invoice/service.go
+++ b/invoice/service.go
@@ -21,6 +21,16 @@ import (
 	e "vidhukant.com/openbills/errors"
 )
 
+// returns greatest invoice number + 1
+func getNewInvoiceNumber(userId uint) (uint, error) {
+	var i uint
+
+	row := db.Model(&Invoice{}).Where("user_id = ?", userId).Select("max(invoice_number)").Row()
+	err := row.Scan(&i)
+
+	return i + 1, err
+}
+
 func getInvoice(invoice *Invoice, id uint) error {
 	res := db.Preload("BillingAddress").Preload("ShippingAddress").Preload("Items").Find(&invoice, id)