SQL中計(jì)算字段的累加和的函數(shù)是？統(tǒng)計(jì)項(xiàng)目數(shù)的函數(shù)是？有誰(shuí)知道嗎？計(jì)算字段的累加和的函數(shù)是 Sum()，統(tǒng)計(jì)項(xiàng)目數(shù)的函數(shù)是Count()怎么用一個(gè)SQL語(yǔ)句將字符串累加？先將數(shù)字轉(zhuǎn)為字符串相加，SQL

SQL中計(jì)算字段的累加和的函數(shù)是？統(tǒng)計(jì)項(xiàng)目數(shù)的函數(shù)是？有誰(shuí)知道嗎？

計(jì)算字段的累加和的函數(shù)是 Sum()，統(tǒng)計(jì)項(xiàng)目數(shù)的函數(shù)是Count()

怎么用一個(gè)SQL語(yǔ)句將字符串累加？

先將數(shù)字轉(zhuǎn)為字符串相加，SQL提供了相關(guān)函數(shù)； 代碼如下： UPDATE T_TABLE SET C= (A STR(B) ) -- T_TABLE 表名！

關(guān)于SQL計(jì)算累加？

如果你year和month是字符型的話(huà)用這個(gè)，把表名換一下，我起的叫test（一共兩處）

select b.year，b.month，sum(a.membercount)

from test a，test b where format(a.year "-" a.month "-01")

group by b.year，b.month

order by format(b.year "-" b.month "-01")

如果你year和month是數(shù)字型的話(huà)用這個(gè)

select b.year，b.month，sum(a.membercount)

from test a，test b where format(str(a.year) "-" str(a.month) "-01")

group by b.year，b.month

order by format(str(b.year) "-" str(b.month) "-01")