From b56465e996b6d5cc025b14693cf03d187a38660f Mon Sep 17 00:00:00 2001
From: kolaente <konrad@kola-entertainments.de>
Date: Tue, 28 Nov 2017 16:19:59 +0100
Subject: [PATCH] Fixed a bug where a new quantity was inserted when it hasnt
 changed

---
 models/book.go | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/models/book.go b/models/book.go
index 01eee5c..6167908 100644
--- a/models/book.go
+++ b/models/book.go
@@ -57,9 +57,19 @@ func GetQuantityByBook(book Book) (quantity int64, err error) {
 
 // SetBookQuantity sets a new quantity for a book
 func (book Book) setBookQuantity(quantity int64) (err error) {
-	q := Quantity{BookID: book.ID, Quantity: quantity}
-	_, err = x.Insert(q)
-	return err
+	// Check if the quantity already exists and only insert it if not
+	qty, err := GetQuantityByBook(book)
+	if err != nil {
+		return err
+	}
+
+	if qty != quantity {
+		q := Quantity{BookID: book.ID, Quantity: quantity}
+		_, err = x.Insert(q)
+		return err
+	}
+
+	return nil
 }
 
 // GetBookByID gets a Book by its ID