How Can I Perform Case-Sensitive Comparisons in LINQ to Entities?

Case-insensitive comparison in LINQ to Entities

Unlike LINQ to Objects, LINQ to Entities does not directly support case-sensitive comparisons. This is because LINQ to Entities converts Lambda expressions into SQL statements, which are ultimately executed by the database (such as SQL Server). By default, SQL Server uses case-insensitive collation, which means the following query will always return a match regardless of case:

<code>context.Thingies.First(t => t.Name == "ThingamaBob");</code>

Server-side solution

To implement case-sensitive comparison in LINQ to Entities, the database collation of the relevant columns must be modified. For example, the following SQL statement changes the collation of the "Name" column in the "Thingies" table to be case-sensitive:

<code>ALTER TABLE Thingies ALTER COLUMN Name VARCHAR(25) COLLATE Latin1_General_CS_AS;</code>

Client solution

Although not ideal, there is a client-side workaround that leverages both LINQ to Entities and LINQ to Objects:

<code>var result = context.Thingies.Where(t => t.Name == "ThingamaBob")
                   .AsEnumerable()
                   .First(t => t.Name == "ThingamaBob");</code>

In this approach, AsEnumerable() converts the query into an in-memory enumeration, allowing you to perform a secondary case-sensitive comparison using Where(). However, this workaround introduces additional queries to the database.

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