如何将sql限制中的AVG函数的小数位仅限制为2？

Question

我想将平均值的小数限制为2 ..

SELECT grade.GStudNo, AVG(grade.Grade) AS Average, students.LName, students.FName, students.MName, students.Course
FROM students INNER JOIN grade ON students.StudNo = grade.GStudNo
WHERE GSem = '$sem' AND GYear = '$year'
GROUP BY grade.GStudNo
ORDER BY Average ASC LIMIT 3

Answer 1

SELECT grade.GStudNo, ROUND( AVG(grade.Grade),2 ) AS Average, students.LName, students.FName, students.MName, students.Course
FROM students INNER JOIN grade ON students.StudNo = grade.GStudNo
WHERE GSem = '$sem' AND GYear = '$year'
GROUP BY grade.GStudNo
ORDER BY Average ASC LIMIT 3

将它绕到两个地方。

Answer 2

使用ROUND函数包装AVERAGE计算...

Answer 3

也许您正在寻找这个：

SELECT grade.GStudNo, CAST(AVG(grade.Grade) AS DECIMAL(10,2)) AS Average, students.LName, students.FName, students.MName, students.Course
FROM students INNER JOIN grade ON students.StudNo = grade.GStudNo
WHERE GSem = '$sem' AND GYear = '$year'
GROUP BY grade.GStudNo
ORDER BY Average ASC LIMIT 3

这只能得到2个小数位

CAST(AVG(grade.Grade) AS DECIMAL(10,2))