Added "Select" and "AndSelect" to "PetaPoco"

[ssougnez]

Prerequisites

• I have written a descriptive pull-request title
• I have linked this PR to an issue on the tracker at http://issues.umbraco.org/issue/U4-11513

Description

Currently, "PetaPoco" can be used to execute SQL queries by using predicates. For example:

new Sql().Select('*').From<ContentDto>()

However, when only some columns must be retrieved, they have to be specified as string parameters, which is error prone.

new Sql().Select('[cmsContent].[nodeId]').From<ContentDto>()

If a mistake is made in "[cmsContent].[nodeId]", the compiler won't complain but the query won't succeed. It implies that if a database column changes, it's pretty hard to find and replace all occurence of that column name.

This PR adds the possibility to select columns using one or several predicates:

new Sql().Select<ContentDto>(c => c.NodeId, c => c.ContentTypeId)

If no delegate is passed to this function, it selects all the fields ("[table].*).
'AndSelect" must be used to select columns from more than one table (in the case of a join for example):

new Sql().Select<DocumentDto>(d => d.NodeId, d => d.Published)
                .AndSelect<ContentVersionDto>(cv => cv.Id)
                .From<DocumentDto>()
                .InnerJoin<ContentVersionDto>()
                .On<DocumentDto, ContentVersionDto>(left => left.VersionId, right => right.VersionId);

These two methods have been implemented in two versions:

• One that does not expect a ISqlSyntaxProvider argument that is marked as obsolete (just to keep some kind of continuity for people not using ISqlSyntaxProvider... and allowed me to use the current test method as they don't use ISqlSyntaxProvider right now)
• One that does expect a ISqlSyntaxProvider argument that is not marked as obsolete.

The following test have also been added to ensure the functionality behaves as expected:

• Can_Use_Select_With_Star_And_Predicate
• Can_Use_Select_With_One_Column_And_Predicate
• Can_Use_Select_With_Multiple_Column_And_Predicate
• Can_InnerJoin_With_Select_And_AndSelect

Tested on the v7.12, these tests (and all the others from the same class) execute correctly.

[nul800sebastiaan]

Thanks @ssougnez - build is running just fine now and tests are passing 👍

I think this looks good, but I left 2 comments for you to fix some things up!

[nul800sebastiaan]

I see why you did this, but instead, let's just fix the source of the problem. I'd add a field on the BaseUsingSqlCeSyntax class that just initiliazes a new SqlServerSyntaxProvider() which you can then use in your tests. It's not very nice to introduce a new public method that is immediately obsolete. ;-)

[ssougnez]

Ok, I'll have a look at that :-D

[nul800sebastiaan]

Should be SqlCeSyntaxProvider of course since the tests are using CE. :-)

[nul800sebastiaan]

No need to commit this file.

[ssougnez]

Well, actually, I have no idea what that file is :-D

What am I supposed to do with it? Just delete it?

[nul800sebastiaan]

Haha, then don't commit it! 😉

I think it's Visual Studio "trying" to be helpful. :) Yep, just delete it!

[ssougnez]

Sorry, Umbraco is the first project I'm contributing to via Github. It's not that easy to understand quickly :-D But I'd like to contribute more to Umbraco, so I'll try to pay attention to these kind of things.

[nul800sebastiaan]

Not to worry, we're here to help and so far you've done great! 👍

[nul800sebastiaan]

Thanks @ssougnez - all good now and merged, top job! 🏅