Mind your languages with Microsoft LINQ

Data-access sticking plaster?

The application developer-centric approach is to make the database - or any source of data - look like a data structure in an application, which is how LINQ addresses the problem. The database-centric approach has always been that the application developer has to learn SQL.

Given that Hejlsberg has mainly worked on the application language side, it is not surprising that he favors the former approach and, given his experience, these views are well worth very taking seriously.

It just isn't that simple, though. For a start, it can be argued that LINQ is a solution to a problem that shouldn't exist. For example, Hejlsberg has argued that application developers currently: "Have to learn database languages such as SQL and what comes with it, such as stored procedures and data types, while also mastering programming languages such as C#, VisualBasic or even Java."

In a well-designed database it is possible to use features like stored procedures to completely shield the application developer from the tables and therefore the need to write SQL.

To try to forestall comments pointing out that most databases are not well designed and that a knowledge of SQL is essential in order to reach the data therein, I'd like to say: "I know - I agree". But that doesn't stop people arguing that LINQ is treating the symptom, not the disease. Instead of applying the LINQ plaster to the gaping wound, we should be making it easier to create an abstraction layer in the database. Application programmers could then write against that layer rather than the actual tables.

This would also address another criticism leveled at LINQ, which is that whilst it isn't SQL, it still writes directly to the tables. As soon as the table structure is altered, the application breaks.

The bottom line is that it is impossible to know as yet whether LINQ will succeed or fail; ultimately that will depend on whether application developers use it or not. The fact that Microsoft is behind LINQ will encourage some and discourage others. The support of Hejlsberg will influence yet others, myself included, to at least give it a go.®

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