Using Registered Function for SQLite regexp operator in EF query

[klosels]

I know that it's possible to register arbitrary functions with SQLite using the SQLiteConnection.RegisterFunction method and already used them successfully in pure SQL statements.

Is it also possible to use a registered function, specifically for the REGEXP SQLite operator, in a LINQ to Entities query?
I.e. how would I write the query on the db Set, e.g.:

Code: Select all

var doubleNamePersons = db.Set<Person>().Where(p => [b]p.LastName ...???... regexp(".*-..*")[/b]);

Thanks for any advice...

[Shalex]

Refer to viewtopic.php?t=37332.

[klosels]

I thoroughly read the referred topic, but I still don't see how to approach the issue.
I already know:

• *how to register a custom function.
  *that I can then use it in a plain SQL query.
  *that registering as "regexp" will map it to the SQLite REGEXP operator (still in plain SQL)

but that doesn't yet help to use the function in LINQ to Entities because

• *the approach in the topic linked further on applies to collating functions specific to a column, but there's no similar configuration option in SQLiteEntityProviderConfig
  *and no Regexp method exists in SqlFunctions which would map to REGEXP operator either

[Shalex]

You are working with EF6, aren't you?

We will investigate the possibility of using REGEXP operator in EF query and notify you about the result.

[klosels]

Sorry for the slow reply - yes, we're using EF 6.2

Hoping you'll find a way to support this as we'll probably need it soon and where we have no workaround.