SqlMetal fails to create DBML from Sqlite Database

Question

I'm trying to use the new Mono 2.6 SqlMetal tool to create the DBML file for a simple Sqlite Database. The schema is really simple as follows:

CREATE TABLE Tags (
    Id              INTEGER PRIMARY KEY,
    TagName         TEXT,
    Description     TEXT);
CREATE TABLE Trends (
    TagId           INTEGER NOT NULL,
    Timestamp       DATETIME NOT NULL,
    Value           TEXT,
    PRIMARY KEY (tagid, timestamp));

I am trying to create the DBML file using the following:

sqlmetal.exe /conn:"Data Source=MyDatabase.db" /namespace:MyNamespace /provider:Sqlite /dbml:MyDatabase.dbml

I get the following output:

>>> Reading schema from SQLite database
<<< Writing file 'MyDatabase.dbml'
sqlmetal failed:System.InvalidOperationException: There was an error reflecting type 'DbLinq.Schema.Dbml.Database'. --->
 System.InvalidOperationException: DbLinq.Schema.Dbml.Database is inaccessible due to its protection level. Only public types can be processed
  at System.Xml.Serialization.ReflectionHelper.CheckSerializableType (System.Type type, Boolean allowPrivateConstructors ) [0x00000] in <filename unknown>:0
  at System.Xml.Serialization.XmlReflectionImporter.ImportClassMapping (System.Xml.Serialization.TypeData typeData, System.Xml.Serialization.XmlRootAttribute root, System.String defaultNamespace) [0x00000] in <filename unknown>:0
  at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping (System.Xml.Serialization.TypeData typeData, System.Xml.Serialization.XmlRootAttribute root, System.String defaultNamespace) [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping (System.Xml.Serialization.TypeData typeData, System.Xml.Serialization.XmlRootAttribute root, System.String defaultNamespace) [0x00000] in <filename unknown>:0
  at System.Xml.Serialization.XmlReflectionImporter.ImportTypeMapping (System.Type type, System.Xml.Serialization.XmlRootAttribute root, System.String defaultNamespace) [0x00000] in <filename unknown>:0
  at System.Xml.Serialization.XmlSerializer..ctor (System.Type type, System.Xml.Serialization.XmlAttributeOverrides overrides, System.Type[] extraTypes, System.Xml.Serialization.XmlRootAttribute root, System.String defaultNamespace) [0x00000] in <filename unknown>:0  at System.Xml.Serialization.XmlSerializer..ctor (System.Type type) [0x00000] in <filename unknown>:0
  at DbLinq.Schema.Dbml.DbmlSerializer.Write (System.IO.Stream xmlStream, DbLinq.Schema.Dbml.Database dbml) [0x00000] in <filename unknown>:0
  at DbMetal.Generator.Implementation.Processor.WriteSchema (DbLinq.Schema.Dbml.Database dbSchema, ISchemaLoader schemaLoader, DbMetal.Parameters parameters) [0x00000] in <filename unknown>:0
  at DbMetal.Generator.Implementation.Processor.ProcessSchema (DbMetal.Parameters parameters) [0x00000] in <filename unknown>:0

I can use the /code option to create a C# code file, but it always fails when generating a DBML.

Am I missing a subtle commandline option or is this new build of SqlMetal not working for Sqlite?

Answer 1

<sheepish-grin>Would you believe I haven't tried to generate a DBML file before?</sheepish-grin>

Short version: this is a bug that you're hitting, with no workaround. I've filed it as http://code.google.com/p/dblinq2007/issues/detail?id=171.

Longer version: There doesn't appear to be a simple solution to this (aside from "jettison System.Xml.Serialization"), as the referenced DbLinq.Schema.Dbml.Database type can't be public from System.Data.Linq.dll, for ~obvious reasons. A "workaround" of building DbLinq under Linux and using DbMetal.exe doesn't work, due to a different bug.

Sorry for the inconvenience.