Can't specify a column as NonNullable about dpq

[grogancolin]

Yeah, that is an issue :-/
Making a 1 to 1 mapping between SQL and D is a tricky problem, hence I let people like you do it for me :-)

I was thinking however, of having a @CustomConstraint() UDA, that would be usable like:

struct myStruct{
   @PK @serial id;
   @CustomConstraint("NOT NULL") string email;
}

The constraint would be added with an ALTER TABLE call later (similar to how current constraints are added in your ensureSchema function).

I think that would allow the user to deal with situations like this.
I don't think it'd be overly hard to add either, hopefully I'll get time to experiment with it soon.

Edit: The reason I think a @CustomConstraint may be easier than implementing a @NotNullable is that it's quite obvious to the programmer that what your doing is something custom that isn't handled normally by dpq, and thus you need to take special care here.

[IrenejMarc]

I'll look into it in the coming days, thanks for the input. :)

[IrenejMarc]

You're correct, there is currently no way to specify NOT NULL with dpq.

Implementing support for it through @notNullable or similar should not be an issue, but there is however, the issue of what values can actually be nullable according to D. Scalar values cannot be nullable and need to be specified so using the Nullable template, same goes for structs, but not classes or other heap-allocated resources.
Does this mean we should simply assume all D scalar values to be NOT NULL? I'm not sure I want to make such assumptions.

[katyukha]

Also @grogancolin's idea of CustomConstraint may help to deal with other SQL constraints like CHECK (price > 0), etc

[grogancolin]

Thanks @IrenejMarc !

[IrenejMarc]

v0.8.7 adds support for this https://github.com/IrenejMarc/dpq/releases/tag/v0.8.7

No full constraint support for now, since those would have to operate on a tables themselves, not columns and I can't think of a way to make that look nice right now :)