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I am porting our product's database to SQLite from another product that supported Guids. As we know, SQLite does not support Guids. I've got created an entity framework 6 model from my database (database first) and I need to build a query from C# that compares the Guid to one passed from the code.

The thing is I can't find any documentation on how the SQLite Entity Framework provider handles Guids. A web search didn't find anything useful for me, either. Just questions about using Entity Framework with SQLite.

Can anybody point me to the documentation, or maybe tell me how to work with Guids in a SQLite database through an EF6 model?

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  • SQLite doesn't have an explicit column type GUID, but storing them with type affinity BLOB works perfectly fine. Don't know much about Entity Framework, but it seems type converters (beyond enums) will be only in EF 7. But GUID has a CTor from byte array etc, so it might be pretty straightforward. Commented Dec 3, 2014 at 18:45
  • I'm storing them as BLOBs in my model, however, I have a problem. The code has an expression similar to "ID == Guid('xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx') which is throwing an exception because the type of ID in the database is Byte[] and the thing on the right is a Guid. The code in question has to run on our client (the code I'm working on) with SQLite, and on our server, where the database is SQL Server. The expression string can't change. I have to do something on the SQLite side to make the comparison work. I just don't know what. That's why I'm looking for the documentation. Commented Dec 3, 2014 at 18:54
  • In SQLite, you can override the Guid() function: sqlite.org/c3ref/create_function.html (not sure how that works through EF though) Commented Dec 3, 2014 at 19:52
  • That 'Guid()' function does not run in SQLite. It runs in the SQLite Entity Framework provider to convert a string into a Guid. The provider then emits a SQL query which compares the value in the column to the Guid. The problem is that the EF provider doesn't like the expression because the column type in EF is byte[], but the thing being compared is a Guid. I can't seem to find any documentation and the lack of Guid support is killing me. Commented Dec 3, 2014 at 20:35
  • Did you find a solution? I'm having the same problem right now... Commented Dec 15, 2014 at 15:44

3 Answers 3

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It appears that this was resolved in 1.0.95 however broken again in 1.0.97. The solution is to set the BinaryGUID property on the connection string to true and set the following environment variable (before you make the connection)

Environment.SetEnvironmentVariable("AppendManifestToken_SQLiteProviderManifest",";BinaryGUID=True;");

Data Source=c:\mydb.db;Version=3;BinaryGUID=True;

https://www.connectionstrings.com/sqlite/

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6 Comments

I'm using 1.0.97, but setting the environment variable actually breaks it for me. I get System.Data.Entity.Core.ProviderIncompatibleException : The provider did not return a ProviderManifest instance. and an inner exception System.ArgumentException : An entry with the same key already exists.. Only changing the connection string works just fine however.
Great Post! This fixed the problem for me using 1.0.99 and Entity Framework 6
BinaryGUID=True in config file is all I needed to do.
BinaryGUID is today default on. I was forced to disable it to be able to have working queries.
BinaryGUID=true; or BinaryGUID=false is working for me, setting it together wit enviroment variable causes the mentioned An entry with the same key already exists
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I finally have an answer to this problem.

My problem is that the SQLite Entity Framework 6 provider doesn't handle converting literal Guids in your code into SQL properly. That is, a Linq expression of the form

context.MyEntity.Where( x => x.GuidColumn == new Guid("xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx") )

Gets converted into the following SQL:

SELECT GuidColumn, Column1, Column2, . . . Column n
FROM MyEntity AS Extent1
WHERE Extent1.GuidColumn = 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"

This is wrong, since the value stored in the column is a byte array.

According to this problem report on the SQLite site, it turns out that the SQLite team considers this to be a bug in the provider and they are working to fix it in release 1.0.95.0. I don't know when that will be released, but at least they recognize it as a problem and are going to fix it.

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2 Comments

Thats bad.... we have decided to store GUIDs as strings due to this issue
While I am no longer at that company & no longer have access to that code base, I think what we did was put the Guid into a Guid variable & compared against that. As I remember, this is handled correctly.
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If you have an old database which has Blob type Guids, you should convert it to text type to make it work with the new EF-Core versions. more info

UPDATE MyTable
SET GuidColumn = hex(substr(GuidColumn, 4, 1)) ||
                 hex(substr(GuidColumn, 3, 1)) ||
                 hex(substr(GuidColumn, 2, 1)) ||
                 hex(substr(GuidColumn, 1, 1)) || '-' ||
                 hex(substr(GuidColumn, 6, 1)) ||
                 hex(substr(GuidColumn, 5, 1)) || '-' ||
                 hex(substr(GuidColumn, 8, 1)) ||
                 hex(substr(GuidColumn, 7, 1)) || '-' ||
                 hex(substr(GuidColumn, 9, 2)) || '-' ||
                 hex(substr(GuidColumn, 11, 6))
WHERE typeof(GuidColumn) == 'blob';

Also it's better to change its collation to NOCASE:

GuidColumn TEXT NOT NULL COLLATE NOCASE
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