Web Listing 2: Code to Populate the DNA Table with 1 Million Rows
TRUNCATE TABLE dbo.DNA;

INSERT INTO dbo.DNA(n, base)
  SELECT N1.n + (N2.n - 1) * 1000 AS n,
    SUBSTRING(
      'ACGT', CAST(RAND(CHECKSUM(NEWID()))*4 AS INT) + 1, 1) AS base
  FROM dbo.Nums AS N1, dbo.Nums AS N2
  WHERE N1.n <= 1000 AND N2.n <= 1000;