這是查詢有兩條或者兩條以上的數據 --先分組,在統計
select a.code from ldcode a where 1=1 GROUP BY a.code HAVING COUNT(a.code)> 1
這是查詢有3條相同數據的情況 --先分組,在統計
select a.code from ldcode a where 1=1 GROUP BY a.code HAVING COUNT(a.code)= 3
這是查詢有兩條或者兩條以上的數據 --先分組,在統計
select a.code from ldcode a where 1=1 GROUP BY a.code HAVING COUNT(a.code)> 1
這是查詢有3條相同數據的情況 --先分組,在統計
select a.code from ldcode a where 1=1 GROUP BY a.code HAVING COUNT(a.code)= 3