sql語句如何統(tǒng)計(jì)數(shù)量 sql語句統(tǒng)計(jì)數(shù)量,統(tǒng)計(jì)一個字段的值的數(shù)量?
sql語句統(tǒng)計(jì)數(shù)量,統(tǒng)計(jì)一個字段的值的數(shù)量?selecttype,count(*)as總數(shù)量,sum(casewhenlevel="一級"then1else0end)as一級,sum(casewhen
sql語句統(tǒng)計(jì)數(shù)量,統(tǒng)計(jì)一個字段的值的數(shù)量?
selecttype,count(*)as總數(shù)量,sum(casewhenlevel="一級"then1else0end)as一級,sum(casewhenlevel="二級"then1else0end)as二級,sum(casewhenlevel="三級"then1else0end)as三級fromtablegroupbytype樓上的應(yīng)該改改吧
sql語句統(tǒng)計(jì)查詢結(jié)果數(shù)量怎么寫?
如何統(tǒng)計(jì)sql語句查詢出來的條數(shù)可以通過count函數(shù)來實(shí)現(xiàn)。sqlOne:select * from tablename1 where id>5此語句查詢出來多條記錄,之后看做一個新的表。sqlTwo:select conut(*) from (select * from tablename1 where id>5) as tablename2此語句即可查詢出來統(tǒng)計(jì)的記錄條數(shù)。備注:以上方法通用于所有的數(shù)據(jù)統(tǒng)計(jì),如果是單表查詢,可以直接通過:“select count( *) from tablename1 where id>5"的形式查詢出結(jié)果。