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Mysql 其中条件不适用于聚合函数

mysql

Mysql 其中条件不适用于聚合函数,mysql,Mysql,我正在尝试使用下面的查询从表中选择数据 SELECT COUNT(*) AS totalcount,SUM(English) as EnglishTotal, SUM(Tamil) as TamilTotal,SUM(Maths) as MathsTotal, SUM(EVS) as EVSTotal,SUM(Science) as ScienceTotal from StudentMarks where Class='"+Classs+"' and Section='"+Section+"

我正在尝试使用下面的查询从表中选择数据

SELECT COUNT(*) AS totalcount,SUM(English) as EnglishTotal,
SUM(Tamil) as TamilTotal,SUM(Maths) as MathsTotal,
SUM(EVS) as EVSTotal,SUM(Science) as ScienceTotal 
from StudentMarks where Class='"+Classs+"' 
and Section='"+Section+"' and ExamType='"+Exam+"' GROUP BY Section;
我的桌子：

如果我用下面的
ResultSet
检查上述查询

if(!rscount.isBeforeFirst()){   
    System.out.println("Cominggggg iffff");
}
else{
    System.out.println("Cominggggg elsee");
}
即使不满足条件，条件也总是转到其他部分

注意：如果我将查询更改为
SELECT*from StudentMarks，其中Class='“+Classs+”，Section='“+Section+”，ExamType='“+Exam+”那么它工作得很好


有人能告诉我哪里做错了吗？
请尝试下面的查询


SELECT COUNT(*) AS totalcount,SUM(English) as EnglishTotal,
SUM(Tamil) as TamilTotal,SUM(Maths) as MathsTotal,
SUM(EVS) as EVSTotal,SUM(Science) as ScienceTotal 
from StudentMarks where Class='"+Classs+"' 
and Section='"+Section+"' and ExamType='"+Exam+"' GROUP BY Section;



我在where条件后添加了group by子句。
在where子句后使用group by子句。即group by（Sno）参见规范化。RDBMS表不是电子表格