In-memory DBMS's for unit testing

.net data-access-layer embedded-database in-memory
Eric Smith picture Eric Smith · Jan 27, 2009 · Viewed 9.5k times · Source

I am looking for satisfactory options for unit testing my .NET DAL classes; since they're DAL classes, they access the database directly using ADO.NET. Presently I use an instance of a MSSQL database for the testing, but was wondering what faster options there are---since unit tests need to run as quickly as possible, an in-memory solution would be ideal.

I should also mention that I have tied myself to TSQL since I'm only ever going to be using a Microsoft platform.

Answer

ShuggyCoUk picture ShuggyCoUk · Jan 27, 2009

Given that you state:

I should also mention that I have tied myself to TSQL since I'm only ever going to be using a Microsoft platform.

Then Using SqlServer compact Edition may work well for your needs. It will not operate entirely in memory but can operate in a readonly mode (where no edits occur to the main database file so it can be used by multiple tests at once)

There are a few gotchas, no stored procedures are supported, a few data types need to be translated and certain data types have tight limits (notably varchar which can only go to 4000 characters) Linq to Sql also is not properly supported.

Nonetheless I have used a SqlServer Compact Edition as an almost entirely drop replacement for the proper Sql Server database with good results.

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