ADO.NET 2.0 SQLite Data Provider
Version 1.0.11 - Aug 1, 2005
Interop using SQLite 3.22
Written by Robert Simpson (email@example.com)
Released to the public domain, use at your own risk!
This provider was written and tested using the Visual Studio 2005 Beta 2 release.
The latest version can be downloaded here
- DbProviderFactory support, just add the XML below at the machine.config and/or app.config level.
- Full support for ATTACH'ed databases. Exposed as Catalogs in the
schema. When cloning a connection, all attached databases are automatically
re-attached to the new connection.
- DbConnection.GetSchema(...) support includes the MetaDataCollections,
DataSourceInformation, Columns, Tables, Views, Catalogs
and Indexes keywords.
- Enhanced DbDataReader.GetSchemaTable() functionality returns catalog, namespace
and detailed schema information even for complex queries.
- Named and unnamed parameters.
- Full UTF-8 and UTF-16 support.
- Multiple simultaneous DataReaders (one DataReader per Command however).
- Full support for user-defined scalar and aggregate functions, encapsulated into
easy-to-use base class in which only a couple of overrides are necessary to implement
new SQL functions.
- Full support for user-defined collating sequences, every bit as simple to implement
as user-defined functions and uses the same base class.
In order to use the SQLiteFactory and have the SQLite data provider enumerated in
the DbProviderFactories methods, you must add the following segment into either
your application's app.config or the system's machine.config located in the %SystemRoot%\Microsoft.Net\Framework\v2.xxxx\Config
<add name="SQLite Data Provider" invariant="System.Data.SQLite" support="3F" description=".Net Framework Data Provider for SQLite" type="System.Data.SQLite.SQLiteFactory, System.Data.SQLite" />
Compiling for the Compact Framework
I've fully planned to support the Compact Framework in this SQLite wrapper, and
will be getting on with it shortly. It requires a few tweaks to the SQLite
source distribution, but nothing insurmountable.
Development Notes Regarding the SQLite 3 Source Code
Steps for merging the sqlite3 core codebase:
This section is obsolete, but remains for historical purposes. The 1.0.11+
versions of the ADO.NET 2.0 SQLite provider make significant changes to the core
sqlite3 codebase in order to support C++ /clr compiling. Specifically, all
the implicit casts throughout the core codebase must be modified. There are
several hundred of these casts and they must be fixed up every time a new sqlite
version is released.
- Download the latest sqlite3 source from
- Extract the source code to the SQLite.Interop\src directory of this project
- Open the src\select.c file.
- Add #include "../interop.h" to the top of the file where the other include's
- Scroll down the select.c file to around line 748. Change the name of the function static void generateColumnNames to
static void _generateColumnNames (note the underscore in front of the name).
- Compile it.
1.11 - August 1, 2005
1.10 - June 10, 2005
- For everything except the Compact Framework, System.Data.SQLite.DLL is
now the only DLL required to use this provider! The assembly
is now a multi-module assembly, containing both the native SQLite3 codebase and
the C# classes built on top of it. The Compact Framework version (when completed)
will not be able to support this feature, so backwards compatibility with the Compact
Framework has been preserved for the future.
- Fixed a bug in SQLiteCommand.ExecuteScalar() that caused it to stop executing
commands once it obtained the first column of the first row-returning resultset.
Any remaining statements after the row-returning statement was ignored.
1.09a - May 25, 2005
- Fixed a bug in the SQLite3.cs Prepare() function that created a statement even when the SQLite engine returned a NULL pointer.
Typically this occurs when multiple statements are processed and there are trailing comments at the end of the statement.
- Fixed a bug in SQLiteStatement.cs that retrieved parameter names for a parameterized
query. SQLite's parameters are 1-based, and the function was starting at 0.
This was fine when all parameters were unnamed, but for named parameters it caused
the parameters to be out of whack.
1.09 - May 24, 2005
- Fixed a broken helpfile and corrected some obsolete help remarks in SQLiteFunction.cs
- Added a version resource to the SQLite.Interop.DLL.
1.08 Refresh - Mar 24, 2005
- Code merge with the latest 3.21 version of SQLite.
- Removed obsolete methods and properties for Whidbey Beta 2
1.08 - Mar 11, 2005
- Code merge with the latest 3.20 version of SQLite.
- Recompiled the help file to fix a build error in it.
1.07 - Mar 5, 2005
- Added additional #if statements to support the old beta 1 edition of VS2005.
- Code merged the SQLite 3.14 source.
- Made more optimizations to frequently-called functions, resulting in significant
performance gains in all tests.
Recompiled the binaries using the latest VS2005 February CTP, resulting in yet more
significant speed gains. The 100k insert test used to take 3.5 seconds and
the insertwithidentity took almost 8 seconds. With the above two changes,
those tests are now executing in 1.9 and 4.9 seconds respectively.
1.06 - Mar 1, 2005
- Speed-ups to SQLiteDataReader. It was interop'ing unnecessarily every time it tried to
fetch a field due to a logic error.
- Changed/Added some code to SQLiteConvert's internal DbType, Type and TypeAffinity
- Fixed the SQLiteDataReader to obey the flags set in the optional CommandBehavior
flag from SQLiteCommand.ExecuteReader().
- Changed the default page size to 1024 to reflect the defaults of
SQLite. Ignores the "Page Size" connection string option for
memory databases, as tests revealed that changing it resulted in memory
- Performance enhancements to the SQLiteCommand and SQLiteStatement classes which
reduced the 100,000 row insert execution time as well as the various Function execution
1.05 - Feb 25, 2005
- Fixed the SQLite3 C# class step/reset functions to accomodate schema changes
that invalidate a prepared statement. Statements are recompiled transparently.
- Moved all native DLL declarations to an UnsafeNativeMethods class.
- Split several classes into their own modules for readability.
- Renamed many internal variables, reviewed access to variables marked as internal
and altered their protection levels accordingly.
- Due to the presence of the altered sqlite3 codebase and so many added interop
functions, I decided to rename the sqlite3 C project and the DLL to SQLite.Interop.DLL.
This is the same core sqlite3 codebase but designed specifically for this
ADO.NET provider. This eliminates any possibility of someone dropping another
build of sqlite3.dll into the system and rendering the provider inoperable.
In the future if the folks at sqlite.org finally introduce a method of retrieving
column usage for an arbitrary prepared statement, I'll retool this library to be
a lightweight function call wrapper around the core binary distribution.
- Added [SuppressUnmanagedCodeSecurity] attribute to the UnsafeNativeMethods class
which brings VS2005 November CTP execution speeds inline with the December CTP.
- Added a bin directory to the project root where pre-compiled
binaries can be found.
- Added a doc directory where preliminary documentation on the
class library can be found.
- Documented a lot more of the classes internally.
1.04 - Feb 24, 2005
1.03 - Feb 23, 2005
- Removed the SQLiteContext class and revamped the way UserFunctions work to simplify
- Fixed a counting bug in the TestCases class, specifically in the function tests
where I wasn't resetting the counter and it was consequently reporting intrinsic
and raw select calls as being much much faster than they actually were. The
numbers are now much closer to what I expected for performance, with .NET user-functions
still being the slowest, but only by a small margin.
- Small performance tweaks to SQLiteDataReader.
- Added PageSize to the SQLiteConnectionStringBuilder and subsequently to the SQLiteConnection
- Added a PRAGMA encoding=XXX execution statement to the SQLiteConnection after
opening a connection.
- Fixed up SQLiteCommandBuilder to correct implementation errors, which resulted
in an enormous performance boost in the InsertMany test. 10,000 row
insert that executed in 1500ms now executes in 500ms.
- Fixed several errors in the SQLite3_UTF16 class. ToString() was working
incorrectly and the Open() method failed to register user defined functions and
- Fixed a bug in SQLiteCommand.ClearCommands() whereby only the first statement
was being properly cleaned up.
- Fixed a bug in SQLiteDataReader whereby calling NextResult() would not properly
reset the previously-executed command in the sequence.
- Added an InsertManyWithIdentityFetch test, which appends a select clause to populate
the ID of the last inserted row into the InsertCommand, demonstrating ADO.NET's
ability to auto-fetch identity columns on insert.
1.02 - Feb 21, 2005
- Tweaks to the xxx_interop functions that return char *'s, so they also return
the length. Saves an interop call to get the UTF-8 string length during conversion
to a .NET string.
- Reworked the whole interop.c thing into interop.h and reduced the code required
to merge the main sqlite3 codebase.
- Added support for user-defined collations.