Foreign Keys

var country = Table.Create("Country",
    "ID".Int().Identity(1, 1).PrimaryKey(),
    "Alpha2Code".Char(2),
    "Name".NVarChar(100));

var customer = Table.Create("Customer",
    "ID".Int().PrimaryKey(),
    "Country".Char(2).NotNull().References(country["Alpha2Code"]));

CREATE TABLE [Country] ( 
    [ID] INT IDENTITY(1, 1) NOT NULL PRIMARY KEY, 
    [Alpha2Code] CHAR(2), 
    [Name] NVARCHAR(100) 
);
CREATE TABLE [Customer] ( 
    [ID] INT NOT NULL PRIMARY KEY, 
    [Country] CHAR(2) NOT NULL REFERENCES [Country] ( [Alpha2Code] ) 
);

You don’t need to define the “Country” table fully. You can make a simple Table variable and reference columns by name. Fluent SQL doesn’t check that the column exists.

var country = Table.Create("Country");

var customer = Table.Create("Customer",
    "ID".Int().PrimaryKey(),
    "Country".Char(2).NotNull().References(country["Alpha2Code"]));

CREATE TABLE [Customer] ( 
    [ID] INT NOT NULL PRIMARY KEY, 
    [Country] CHAR(2) NOT NULL REFERENCES [Country] ( [Alpha2Code] ) 
);

Named constraints and cascade clauses are not yet supported.