I don't know why. Just move on.

Handlers/Guns/Index.go

@@ -24,6 +24,7 @@ type gunPayload struct {
 }
 
 type gunPost struct {
+	Id             int64  `json:"id"`
 	Make           string `json:"make" validate:"required"`
 	Model          string `json:"model" validate:"required"`
 	SerialNumber   string `json:"serial_number" validate:"required"`
@@ -118,6 +119,57 @@ func DeleteById(c echo.Context) error {
 	return nil
 }
 
+func UpdateGun(c echo.Context) error {
+	gun := new(gunPost)
+	err := c.Bind(gun)
+	if err != nil {
+		return err
+	}
+
+	getDb := sql.GetDb()
+	err = getDb.Queries.UpdateGun(context.Background(), db.UpdateGunParams{
+		Make: sql2.NullString{
+			String: gun.Make,
+			Valid:  true,
+		},
+		Model: sql2.NullString{
+			String: gun.Model,
+			Valid:  true,
+		},
+		SerialNumber: sql2.NullString{
+			String: gun.SerialNumber,
+			Valid:  true,
+		},
+		PurchaseAmount: sql2.NullInt64{
+			Int64: gun.PurchaseAmount,
+			Valid: true,
+		},
+		ValueAmount: sql2.NullInt64{
+			Int64: gun.ValueAmount,
+			Valid: true,
+		},
+		DatePurchased: sql2.NullString{
+			String: gun.DatePurchased,
+			Valid:  true,
+		},
+		Notes: sql2.NullString{
+			String: gun.Notes,
+			Valid:  true,
+		},
+		ID: gun.Id,
+	})
+	if err != nil {
+		return err
+	}
+
+	err = c.JSON(http.StatusOK, "")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 func GetById(c echo.Context) error {
 	id, err := strconv.ParseInt(c.Param("id"), 10, 64)
 	if err != nil {

main.go

@@ -36,6 +36,7 @@ func main() {
 	}))
 
 	e.GET("/gun", Guns.Get)
+	e.PUT("/gun/:id", Guns.UpdateGun)
 	e.GET("/gun/:id", Guns.GetById)
 	e.DELETE("/gun/:id", Guns.DeleteById)
 	e.POST("/gun", Guns.Post)