count(*)與count(column-name)這兩個(gè)示例相比，這樣做是否有所不同？我傾向于總是寫(xiě)，count(*)因?yàn)槿绻尚?，它似乎更適合我的想法，因?yàn)樗且粋€(gè)聚合函數(shù)。但是我不確定這在技術(shù)上是否最好，因?yàn)槲覂A向于看到示例代碼編寫(xiě)時(shí)*經(jīng)常沒(méi)有。計(jì)數(shù)（*）：select customerid, count(*), sum(price) from items_orderedgroup by customeridhaving count(*) > 1;vs. count（列名）：SELECT customerid, count(customerid), sum(price)FROM items_orderedGROUP BY customeridHAVING count(customerid) > 1;