一、distinctmysql
select count(distinct CName) from teble select count(CName) from (select distinct CName from Course) as temp SELECT DISTINCT text_zhcn FROM dms_menuconfig -- 去重查詢表中數據 select DISTINCT(user_id) from user_info where children_merchant_id='kuaiditong';
二、group bysql
select count(1) from Course group by CName
文檔:mysql去重查詢表中數據.note
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