SQL Server

Declare a sqlserver provider using a PROVIDER sqlserver config block:

PROVIDER sqlserver (
  version = '4.0.0',
  connection_string = '',
  command_timeout = 30
);

The NSchema.SqlServer plugin is restored automatically from the pinned version the first time you run a command — for CLI use you don’t install it by hand. (To embed the engine as a library instead, see Using the library.)

Requirements

The provider targets SQL Server 2016 SP1 or newer (including Azure SQL Database). Views and routines are replaced in place with CREATE OR ALTER, which requires this baseline.

Attributes

Attribute	Type	Description
version	string	Required. The version of the NSchema.SqlServer plugin package to restore.
source	string	Optional. A NuGet package id to load the provider from instead of NSchema.SqlServer.
connection_string	string	The connection string used to reach the database. Best supplied via the environment (see below).
username	string	The username, supplied separately from the connection string. Overrides any user embedded in it.
password	string	The password, supplied separately from the connection string. Overrides any password embedded in it.
command_timeout	integer	The command timeout, in seconds.

The connection string

The connection string is a secret, so you should probably supply it through an environment variable rather than committing it, but I promise not to report you to the connection string police:

export NSCHEMA_SQLSERVER_CONNECTION_STRING="Server=localhost;Database=app;User Id=sa;Password=hunter2;TrustServerCertificate=True"

NSCHEMA_SQLSERVER_CONNECTION_STRING takes precedence over a connection_string set in the block.

Credentials supplied separately

When a secret store (e.g. AWS Secrets Manager) injects the database username and password out of band, keep only the non-secret host/database in the connection string and supply the credentials on their own:

export NSCHEMA_SQLSERVER_CONNECTION_STRING="Server=db.internal;Database=app;TrustServerCertificate=True"
export NSCHEMA_SQLSERVER_USERNAME="$DB_USER"
export NSCHEMA_SQLSERVER_PASSWORD="$DB_PASSWORD"

These (also settable as username / password in the block) override any user/password embedded in the connection string. The base connection string is applied first, then the discrete overrides are layered on top. See Environment variables.

Identifiers and dialect

Identifiers are emitted bracket-quoted ([schema].[name]), so reserved words and unusual names are always safe.

What’s supported

SQL Server is a full server database, so this provider covers most of NSchema’s model:

• Supported: schemas, tables, columns (with DEFAULT, IDENTITY, and persisted computed columns), primary keys, foreign keys, unique constraints, check constraints, indexes (including INCLUDE columns and filtered indexes), views, sequences, scalar/table functions and stored procedures, table-level GRANTs, triggers, and documentation comments (stored as MS_Description extended properties).

Using the library

When embedding the engine instead of the CLI, register SQL Server with the NSchema.SqlServer package:

dotnet add package NSchema.Core
dotnet add package NSchema.SqlServer

UseSqlServerSchema wires up both the current-schema provider and the SQL generator. The two connection-aware overloads also register the connection source the provider reads from and the data source the executor applies through:

// 1. Connection string.
builder.UseSqlServerSchema("Server=localhost;Database=app;User Id=sa;Password=…;TrustServerCertificate=True");

// 2. Configure the SqlConnectionStringBuilder directly.
builder.UseSqlServerSchema(b =>
{
    b.DataSource = "localhost";
    b.InitialCatalog = "app";
    b.IntegratedSecurity = true;
    b.TrustServerCertificate = true;
});

If you only need DDL generation and not introspection (for example, to render the migration SQL without connecting to a database), register just the generator with UseSqlServerGenerator().

SQL Server-specific types

SqlTypeSqlServerExtensions adds SQL Server-only members to SqlType for code-built schemas:

Member	SQL Server type	Notes
SqlType.Money	money	Fixed-point currency value.
SqlType.Xml	xml	XML documents and fragments.
SqlType.RowVersion	rowversion	Automatically maintained row-version stamp.

In DDL you write these as ordinary type names (money, xml, rowversion); unrecognized names pass through as custom types.