有人问怎么求1到100的质数,所以就试着用sql写了个
WITH x1 AS (SELECT LEVEL + 1 AS id FROM dual CONNECT BY LEVEL <= 99), x2 AS (SELECT a.id, a.id / b.id AS num FROM x1 a, x1 b WHERE a.id <> b.id) SELECT DISTINCT id FROM x2 WHERE id NOT IN (SELECT DISTINCT id FROM x2 WHERE num NOT LIKE ‘%.%‘) ORDER BY 1 ID ---------- 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97
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