SQL控制流程函数CASE...

发布时间：2024-12-05 20:41

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最新推荐文章于 2022-08-24 23:23:06 发布

ajaxuser 于 2011-10-09 17:06:39 发布

SELECT (

CASE `table1`.`parent_code`

WHEN '01'

THEN '媒体'

WHEN '02'

THEN '品牌'

WHEN '03'

THEN 'BD'

END

) AS 一级名称, `table1`.`name` AS 二级名称, `table2`.`name` AS 三级名称

FROM `table2`

LEFT JOIN `table1` ON ( `table1`.`code` = `table2`.`parent_code` )

WHERE `table2`.`name`

IN (

SELECT `name`

FROM `table2`

GROUP BY `name`

HAVING count(*) >1

)

按照name分组并统计name出现的次数，HAVIN过滤分组信息

SELECT `name`, count(*) FROM `table2` GROUP BY `name` HAVING count(*) > 1

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