How to Initialize sql.NullString in GORM Models?

Unable to Use String as sql.NullString: Type Conversion Required

When creating a gorm model and using sql.NullString, an error may arise indicating the inability to use a string as an sql.NullString. This is because sql.NullString is a struct with specific requirements for initialization.

To resolve this issue, the Something field should be initialized using the correct syntax:

<code class="golang">db.Create(&Day{
    Nameday:     "Monday",
    Dateday:     "23-10-2019",
    Something:   sql.NullString{String: "a string goes here", Valid: true},
    Holyday:     false,
})</code>

As an alternative, a custom nullable string type can be created to allow simpler syntax:

<code class="golang">type MyString string

const MyStringNull MyString = "\x00"

// Implement the necessary interfaces for GORM
func (s MyString) Value() (driver.Value, error) { ... }
func (s *MyString) Scan(src interface{}) error { ... }</code>

With this custom type, the Something field can be initialized as originally intended:

<code class="golang">db.Create(&Day{
    Nameday:     "Monday",
    Dateday:     "23-10-2019",
    Something:   "a string goes here",
    Holyday:     false,
})</code>

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