Can I custom the transaction error message?

[zemelLeong]

[weiznich]

Please include some more details about what you actually want to know instead of an image.

[zemelLeong]

I want return a custom error in transaction. Such as return Err("Invalid version").
But as far as I know it only support diesel::result::Error.
Is there any way to return a custom error message in transaction?

[weiznich]

As you can see by looking at the function signature of Connection::transaction it does support any error type as long as it implements From<diesel::result::Error>. You just need to specify which type should be used as part of the generic arguments of that function or write your code in such a way that rustc is able to infer exactly one type.

[zemelLeong]

Thanks a lot.

#[derive(Debug)]
struct CusErr {
    pub message: String
}

impl From<Error> for CusErr {
    fn from(_: Error) -> Self {
        CusErr {
            message: "Invalid version".to_string()
        }
    }
}

if old_doc.object_version_number != value.object_version_number {
    return Err(CusErr::from(Error::NotFound));
}