最后的行列轉(zhuǎn)換在Oracle中沒(méi)有實(shí)現(xiàn)
2018-03-28
Interesting,捕獲經(jīng)驗(yàn)怪一只[滑稽]
2018-03-21
表示數(shù)據(jù)挖掘模型的數(shù)據(jù)輸入經(jīng)常需要行轉(zhuǎn)列的數(shù)據(jù)預(yù)處理,大家也別說(shuō)沒(méi)用,只是我們用得著不代表所有人都用得著
2018-03-20
這個(gè)是不是在php等中分割字符然后比較有相同的就刪除掉然后再更新表好一點(diǎn)
2017-09-01
delete a from user1_test a join(select id, user_name,count(*) from user1_test group by user_name having count(*)>1) as b on a.user_name = b.user_name where a.id>b.id; 更容易看懂吧
2017-09-01