SQL Server - pull X random records per state

问题:

I have a table with records for each zip code in the united states. For the purposes of displaying on a map, I need to select X random records per state. How would I go about doing this?

回答1:

Use:

WITH sample AS (
 SELECT t.*,
        ROW_NUMBER() OVER (PARTITION BY t.state
                               ORDER BY NEWID()) AS rank
   FROM ZIPCODES t)
SELECT s.*
  FROM sample s
 WHERE s.rank <= 5

回答2:

SELECT * FROM ZipCodes ORDER BY NEWID()