sqlc
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sqlc-dev
Optionally replace sql.Null* types with pointers
What do you want to change?
Structs generated by sqlc which contain null fields use the sql.Null* types. However, it would be nice if there was an option to use a pointer instead. So instead of sql.NullString we could use *string. The reason has to do with serialization since sql.NullString is an object you must manually define your serialization format for.
Consider the following object
type User struct {
Name sql.NullString
Email string
}
which JSON encoded looks like
{
"Name": {
"String": "john",
"Valid": true
},
"Email": "[email protected]"
}
And JSON decoded looks like: Unmarshal type error: expected=sql.NullString, got=string, field=Name and json: cannot unmarshal string into Go struct field User.Name of type sql.NullString. We must manually wrap sql.NullString to add proper marshaling support for each transport like JSON:
// Nullable String that wraps sql.NullString
type NullString struct {
sql.NullString
}
func (ns NullString) MarshalJSON() ([]byte, error) {
if ns.Valid {
return json.Marshal(ns.String)
}
return json.Marshal(nil)
}
func (ns *NullString) UnmarshalJSON(data []byte) error {
var s *string
if err := json.Unmarshal(data, &s); err != nil {
return err
}
if s != nil {
ns.Valid = true
ns.String = *s
} else {
ns.Valid = false
}
return nil
}
Of course, we could also manually update the configuration for every single null type in our database using overriding but that seems like a lot of work when we could just use pointers instead.
If I submit a PR to add an option like emit_struct_field_pointers would you potentially accept it?
What database engines need to be changed?
No response
What programming language backends need to be changed?
Go
We have a pull request that adds this in https://github.com/kyleconroy/sqlc/pull/1571. That PR is a bit stale at this point, but could be cleaned up.
