Implement diesel Expression for more types

[lephyrius]

error: the trait `diesel::expression::Expression` is not implemented for the type `u64` 

I got this error.
I solved it with this:

let game = games.filter(id.eq(params.find("id").unwrap().as_u64().unwrap() as i32 )).first(&connection);

This is a bit ugly. Could there be more types supported than just i32?
Any other suggestion than moving this cast to a function?

[sgrif]

All integer types are supported for use where appropriate. Unfortunately, the error messages can sometimes be unhelpful due to rust-lang/rust#28894. The trait that it's failing to find is probably AsExpression<types::Integer>. What's allowed here is based on the type of id. It seems likely that your column is of type Integer or Serial, which are both 32 bit signed integers. You can't write 32bit_column.eq(1i64). For BigInteger, you can use 64 bit integers as well. However keep in mind that this type is also signed, and you can only use i64 not u64. PostgreSQL does not have an unsigned integer type.

If my assumptions about your app are incorrect, let me know and I'll re-open.

[JohnMH]

Why is there no "sql type" for unsigned integers? In MySQL, for example, it is perfectly valid to have an INT UNSIGNED.

[weiznich]

@JohnMH See #1561 for unsigned integers in MySQL