These are the "common" parameters used by all SqlProviders.
All static parameters must be known at compile time, for strings this can be
achieved by adding the
[<Literal>] attribute if you are not passing it inline.
This is the connection string commonly used to connect to a database server instance. See the documentation on your desired database type to find out more.
let sqliteConnectionString =
"Data Source=" + __SOURCE_DIRECTORY__ + @"\northwindEF.db;Version=3"
Instead of storing the connection string in the source code /
fsx script, you
can store values in the
Another, usually easier option is to give a runtime connection string as parameter for
In your source file:
let connexStringName = "MyConnectionString"
Select enumeration from
Common.DatabaseProviderTypes to specify which database
type the provider will be connecting to.
let dbVendor = Common.DatabaseProviderTypes.SQLITE
When using database vendors other than SQL Server, Access and ODBC, a third party driver is required. This parameter should point to an absolute or relative directory where the relevant assemblies are located. See the database vendor specific page for more details.
let resolutionPath =
__SOURCE_DIRECTORY__ + @"..\..\..\files\sqlite"
If you are publishing your app using .NET 5's PublishSingleFile mode, the driver will be loaded from the bundle itself rather than from a separate file on the drive. As such, the ResolutionPath parameter will not work for the published app, nor will the automatic assembly resolution implemented within SQLProvider.
SQLProvider attempts to load the assembly from the AppDomain in such case. This means
that your driver's assembly must be loaded by your application for SQLProvider to find
it. To do so, simply use the types of your driver before calling the
method, such as in this example, using MySqlConnector. The specific type you refer
to does not matter.
typeof<MySqlConnector.Logging.MySqlConnectorLogLevel>.Assembly |> ignore
let ctx = sqlType.GetDataContext()
Number of instances to retrieve when using the individuals feature. Default is 1000.
let indivAmt = 500
If set to FSharp.Data.Sql.Common.NullableColumnType.OPTION, all nullable fields will be represented by F# option types. If NO_OPTION, nullable fields will be represented by the default value of the column type - this is important because the provider will return 0 instead of null, which might cause problems in some scenarios.
The third option is VALUE_OPTION where nullable fields are represented by ValueOption struct.
let useOptionTypes = FSharp.Data.Sql.Common.NullableColumnType.OPTION
ContextSchemaPath and placing a file with schema information according to the definition
enables offline mode that can be useful when the database is unavailable or slow to connect or access.
Schema information file can be generated by calling design-time method
Design Time Commands:
ctx.``Design Time Commands``.SaveContextSchema
This method doesn't affect runtime execution. Note that since SQLProvider loads schema information lazily,
SaveContextSchema only saves the portion of the database schema that is sufficient to compile
queries referenced in the scope of the current solution or script. Therefore it is recommended to execute
it after the successful build of the whole solution. Type the method name with parentheses, if you then
type a dot (.), you should see a tooltip with information when the schema was last saved. Once the schema
is saved, the outcome of the method execution is stored in memory, so the file will not be overwritten.
In case the database schema changes and the schema file must be updated, remove the outdated file, reload
the solution and retype or uncomment a call to
SaveContextSchema to regenerate the schema file.
There is a tool method FSharp.Data.Sql.Common.OfflineTools.mergeCacheFiles to merge multiple files together.
let contextSchemaPath =
__SOURCE_DIRECTORY__ + @".\sqlite.schema"
TableNames to filter amount of tables.
TableNames to filter amount of tables, and Owner.
This has different meanings when running queries against different database vendors
For PostgreSQL, this sets the schema name where the target tables belong to. Can be also a list separated by spaces, newlines, commas or semicolons.
For MySQL, this sets the database name (Or schema name, for MySQL, it's the same thing). Can be also a list separated by spaces, newlines, commas or semicolons.
For Oracle, this sets the owner of the scheme.
The additional SQLiteLibrary parameter can be used to specify which SQLite library to load.
No extra parameters.
No extra parameters.
No extra parameters.
It is recommended to use named static parameters in your type provider definition like so
type sql = SqlDataProvider<
ConnectionString = sqliteConnectionString,
DatabaseVendor = dbVendor,
ResolutionPath = resolutionPath,
UseOptionTypes = useOptionTypes
Besides the static parameters the
.GetDataContext(...) method has optional parameters: