refactor: delete unnessesary code

models/testdata.go

@@ -1,29 +0,0 @@
-package null_safety
-
-type Order1 struct {
-	Id          uint `gorm:"primaryKey"`
-	Description string
-	// not nullable - not nullable
-	CustomerId uint `gorm:"not null;foreignKey:CustomerId;"`
-}
-
-type Order2 struct {
-	Id          uint `gorm:"primaryKey"`
-	Description string
-	// nullable - nullable
-	CustomerId *uint `gorm:"null;foreignKey:CustomerId;"`
-}
-
-type Order3 struct {
-	Id uint `gorm:"primaryKey"`
-	// nullable - unspecified
-	Status      *string
-	Description string
-}
-
-type Order4 struct {
-	Id uint `gorm:"primaryKey"`
-	// not nullable - unspecified
-	Status      *string
-	Description string
-}