Field tags now allow you to declare a primary key or autoincrement field

[meetmauro]

With this patch you can declaratively say:

type Product struct {
Id int64 db:"product_id" flags:"pk, autoincrement"
Price int64 db:"unit_price"
IgnoreMe string db:"-"
}

so that your AddTableWithName will be simpler like:
t1 := dbmap.AddTableWithName(Invoice{}, "invoice_test")

instead of using SetKeys to specify keys on fields.

[coopernurse]

Apologies I haven't commented. I like the idea, but I wonder if we should use the same "db" tag for all of these attributes, rather than introducing another tag. For example:

type Product struct {
    Id int64 db:"product_id,pk,autoincrement"
    Price int64 db:"unit_price"
    IgnoreMe string db:"-"
}

That would follow the convention used in the encoding/json package (and probably others).

Thoughts?

[coopernurse]

I should clarify: the first item in the comma separated list would always be the column name, similar to the way the json tag works.

[sqs]

+1 to using the same tag name, following the convention of encoding/json (which, by the way, has some unexported helper functions you could copy to parse the tag).

[lukescott]

I would personally prefer "name,autoincrement" and "name,primary" over "name,pk,autoincrement" and "name,pk". In the case of "autoincrement", "primary" would naturally be assumed.

[insasho]

@lukescott auto-increment columns are not always primary keys.

[GeertJohan]

@meetmauro Can you see if the requested changes can be made to this PR? I'd be happy to add this feature to the codebase.
If so, please:

• Rebase the PR on the latest master
• Use attributes in the same db tag
• Change pk to primarykey

[meetmauro]

OK. Rebased and made suggested changes in a new PR.

[GeertJohan]

New PR: #233