Integer enum in SQLite3

[keepsimple1]

Hi,

I am using diesel with SQLite3. What is the best way to support integer enum values in a column?

For example, I have defined a column like this in SQL schema:

    foo_state INTEGER NOT NULL, -- the value will be from an Enum.

in diesel_schema.rs, I also simply define it as integer:

        foo_state -> Integer,

But in actual source code, I would like to define the struct for inserting and querying including this field as:

struct Foo {
    pub foo_state: FooState,
}

where FooState is an Enum like this:

pub enum FooState {
    Unknown = 0,
    Start = 1,
    End = 2,
}

The problem is that it is quite difficult to use the enum directly with diesel ORM methods. I had to implement FromSql and ToSql traits for FooState:

impl<DB> FromSql<Integer, DB> for FooState {
<snip>
}

impl<DB> ToSql<Integer, DB> for FooState {
<snip>
}

After that, I can use the enum in Insertable struct, and QueryableByName struct, but it seems I still cannot use the enum in a Queryable struct.

Did I miss something obvious & easier way to use integer enum fields? Is it possible to use the enum field in a struct as Queryable ?

Thanks.

[weiznich]

You likely miss one of these derives.

Otherwise there is this third party crate, which provides an opinionated way to implement such mappings.