Implemented 'Array' type for Postgres.

[kev0960]

This introduces "Array" as a new Value variant.

It can be derived from all Vec types, where T is a valid Value, except for u8, which is already handled by Bytes.

Note that sqlx and postgres-types already supports an array, so this can be implemented without too much hassle.

[kev0960]

Hmm, actually, this will not work because we cannot provide bindings to Sqlx.

Sqlx expects Vec<T> for an array, and we have to somehow convert Vec<Value> to Vec<T>. :(

[billy1624]

Hey @kev0960, thanks for the contributions! I assumed you want to support Vec<T> in sea-orm for Postgres?

[kev0960]

Yes I do :)

[kev0960]

I don't like the idea but we can probably workaround by defining bunch of definitions like

ArrayInt32(Option<Vec<i32>>),
ArrayInt64(Option<Vec<i64>>),
ArrayString(Option<Vec<String>>),
...

and treat them individually. I really cant think of the "clean" way to convert the generic Array(Option<Vec<Value>>) into Vec<ConcreteType> since "Value" does not really carry the type we have to convert to.

Any ideas are welcomed :)

[billy1624]

Let me think loll :P

[psibi]

Do you think a solution like this will work out:

pub enum Value<A> {

and then this becomes:

    Array(Option<Box<Vec<A>>>),

We would have to convert the other code to account for the generic argument, but I'm thinking if such a approach will work.

[billy1624]

pub enum Value<A> {

So, A is unbounded? Why is this necessary?

[tyt2y3]

Sorry for the late reply. Actually, this looks very good!

[billy1624]

Hey @tyt2y3, I think something is missing in this PR and it shouldn't be merged into master yet.

Binding array values to SQLx PostgreSQL is not ready

• https://github.com/SeaQL/sea-query/runs/4502670225