在SQL在多列中计算不同的值对
哪个查询将计算行数,但由三个参数区分?例子:
Id Name Address ==============================1 MyName MyAddress2 MySecondNameAddress2就像是:
select count(distinct id,name,address) from mytable
解决方案:
要获得的唯一组合数的计数id,name并且address:
SELECT Count(*)FROM ( SELECT DISTINCT id name address FROM your_table ) As distinctified
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