Report-Designer support for ORM (.NET)

entity-frameworknetnhibernateormreporting

Say I have an application that used an ORM (I am thinking of nHibernate or LINQ to Entities) for data access. How do I provide my users with the ability to do reporting against the properties of my objects? All the end user report designers I know of talk directly to a database, but I don’t like having to repeat logic in reports that are already in the application’s objects.

Are there yet any standard solutions?

I am hoping for a system that use reflection (or some other method) to get the schema from my objects, then lets the user build up a linq query that can run against an IQueryable that I provide.

Having to write all the data retrieval logic myself is not appealing. Creating DataSets to represent all my objects is even less appealing. (If I liked Datasets I would not be looking at ORM systems)

Is the new .NET RIA Services a good bases for a solution?

Best Answer

You may also have a look at XtraReports from DevExpress

XtraReports can generate reports from any data source that implements IList, ITypedList or IBindingList interface.

Related Solutions

The “N+1 selects problem” in ORM (Object-Relational Mapping)

Let's say you have a collection of Car objects (database rows), and each Car has a collection of Wheel objects (also rows). In other words, Car → Wheel is a 1-to-many relationship.

Now, let's say you need to iterate through all the cars, and for each one, print out a list of the wheels. The naive O/R implementation would do the following:

SELECT * FROM Cars;

And then for each Car:

SELECT * FROM Wheel WHERE CarId = ?

In other words, you have one select for the Cars, and then N additional selects, where N is the total number of cars.

Alternatively, one could get all wheels and perform the lookups in memory:

SELECT * FROM Wheel

This reduces the number of round-trips to the database from N+1 to 2. Most ORM tools give you several ways to prevent N+1 selects.

Reference: Java Persistence with Hibernate, chapter 13.

C# – .NET String.Format() to add commas in thousands place for a number

String.Format("{0:n}", 1234);  // Output: 1,234.00
String.Format("{0:n0}", 9876); // No digits after the decimal point. Output: 9,876

Best Answer

Related Solutions

The “N+1 selects problem” in ORM (Object-Relational Mapping)

C# – .NET String.Format() to add commas in thousands place for a number

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