sql語(yǔ)句怎么進(jìn)行分組查詢 sql如何求分組計(jì)數(shù)之后計(jì)數(shù)的最大值?
sql如何求分組計(jì)數(shù)之后計(jì)數(shù)的最大值?Select max(a)from(Select x1,X2,count(*)as from table group by x1,X2)我說(shuō)絕對(duì)沒(méi)問(wèn)題。子查詢,X
sql如何求分組計(jì)數(shù)之后計(jì)數(shù)的最大值?
Select max(a)from(Select x1,X2,count(*)as from table group by x1,X2)我說(shuō)絕對(duì)沒(méi)問(wèn)題。子查詢,X1和X2是指您分組的字段,count(*)是指分組后的行數(shù)(count),定義別名是主查詢的最大技術(shù)。注意,from之后的子查詢還定義了一個(gè)表別名