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生成3位的序列号_仅仅CASE WHEN的简单应用

Posted on 2018-10-18 15:31  竹子柱  阅读(363)  评论(0)  编辑  收藏  举报 
 1 SELECT TOP 200
 2     PNo, IDENTITY( INT,1,1 ) AS sn
 3 INTO
 4     #temp1
 5 FROM
 6     tbl_test 
 7 
 8 SELECT
 9     CASE WHEN sn < 10 THEN '00' + CONVERT(CHAR(1), sn)
10          WHEN sn >= 10
11               AND sn <= 99 THEN '0' + CONVERT(CHAR(2), sn)
12          WHEN sn >= 100 THEN CONVERT(CHAR(3), sn)
13     END AS sn, PNo
14 FROM
15     #temp1