Databases and the D Standard Library

[Adam Wilson via Digitalmars-d]

Chris Wright wrote:
> On Sun, 01 Jan 2017 10:29:28 +0100, Jacob Carlborg wrote:
>
>> On 2017-01-01 04:24, Adam Wilson wrote:
>>
>>> My idea: Each data store has it's own implementation with it's own
>>> naming convention. For example (ADO.NET):
>>>       - SqlConnection (MSSQL)
>>>       - NpgsqlConnection (Npgsql)
>>>
>>> Yes, this means that you have to change names in your code if you
>>> switch data-stores, but since you are already changing your queries,
>>> which is a much more difficult change, this isn't a significant
>>> additional cost.
>>
>> I don't think we should try to make implementations different just
>> because. If you have an SQL builder or an ORM on top of the interface
>> that abstract the differences in the SQL syntax, it's possible to switch
>> driver, within reason.
>
> Those both limit your ability to use the underlying database to its full
> potential. They offer a chance for queries that seem simple and efficient
> to become horribly inefficient.
>

I cannot state my agreement with this paragraph enough. Every ORM I've 
worked with generates some inexplicably horrific SQL in seemingly simple 
situations.

> I ran across a problem in NHibernate about a decade ago. We had a
> straightforward HQL query involving joins. It took over a minute to run.
> We wrote the simple equivalent in SQL and it completed in milliseconds.
> Fortunately, NHibernate had the ability to run raw SQL queries.
>

I've also seen Entity Framework 6/7 do the same thing.

-- 
Adam Wilson
IRC: LightBender
import quiet.dlang.dev;