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如何计算两列中具有相同值的行,并仅返回count计数的行

[英]How to count rows that have the same values in two columns and return only rows where count<N(SQL)?

regarding that question: How to count rows that have the same values in two columns (SQL)? 关于这个问题: 如何计算两列中具有相同值的行(SQL)?

is there a way to return only the rows where the count is < 3? 有没有办法只返回计数<3的行?

+-----+-----+-----+
|  A  |  B  |count|
+=====+=====+=====+
|  1  |  3  |  2  |
+-----+-----+-----+
|  4  |  2  |  1  |
+-----+-----+-----+

The HAVING clause HAVING子句

 SELECT ...
 FROM ...
 WHERE ...
 GROUP BY whatever
 HAVING count(*) <3

Just add the condition in the HAVING clause 只需在HAVING子句中添加条件即可

SELECT colName, COUNT(*)
FROM tableName
GROUP BY colName
HAVING COUNT(*) < 3

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