Question

I have this Data in DB

CREATE TABLE Stu_Table
(
    Stu_Id VARCHAR(2),
    Stu_Name VARCHAR(15), 
    Stu_Class VARCHAR(10),
    sub_id VARCHAR(2),
    marks VARCHAR(3)
);

INSERT INTO Stu_Table VALUES (1, 'Komal', 10, 1, 45);
INSERT INTO Stu_Table VALUES (2, 'Ajay', 10, 1, 56);
INSERT INTO Stu_Table VALUES (3, 'Rakesh', 10, 1, 67);
INSERT INTO Stu_Table VALUES (1, 'Komal', 10, 2, 47);
INSERT INTO Stu_Table VALUES (2, 'Ajay', 10, 2, 53);
INSERT INTO Stu_Table VALUES (3, 'Rakesh', 10, 2, 57);
INSERT INTO Stu_Table VALUES (1, 'Komal', 10, 3, 45);
INSERT INTO Stu_Table VALUES (2, 'Ajay', 10, 3, 56);
INSERT INTO Stu_Table VALUES (3, 'Rakesh', 10, 3, 67);
INSERT INTO Stu_Table VALUES (1, 'Komal', 10, 4, 65);
INSERT INTO Stu_Table VALUES (2, 'Ajay', 10, 4, 56);
INSERT INTO Stu_Table VALUES (3, 'Rakesh', 10, 4, 37);
INSERT INTO Stu_Table VALUES (1, 'Komal', 10, 5, 65);
INSERT INTO Stu_Table VALUES (2, 'Ajay', 10, 5, 46);
INSERT INTO Stu_Table VALUES (3, 'Rakesh', 10, 5, 63);

And I’m doing this query on this data.

SELECT *
FROM
(
    SELECT
        Stu_Id,
        MIN(marks) AS mini,
        AVG(marks) AS per
    FROM stu_table
    GROUP BY stu_id
    HAVING MIN(marks) > 45
);

And I’m getting this:

Stu_Id| mini  |  per
   1  |  45   |  53.4
   2  |  46   |  53.4
   3  |  37   |  58.2

I don’t understand why I still see Stu_Id 1 with min(mark)=45 when I clearly have this HAVING min(marks)>45 in my query.

Runnable Demo

FIX:
Thanks to @sybkar and @Martin Smith!

I set the marks type as a string.
It’s should be INT…

Thanks guys!
Working perfect!

create table Stu_Table(Stu_Id INT(2), Stu_Name varchar(15), 
Stu_Class  varchar(10),sub_id INT(2),marks INT(3));<--INT!!!

Answer 1

I don’t understand why I still see Stu_Id 1 with min(mark)=45
when I clearly have this HAVING min(marks)>45 in my query.

You don’t. Or at the least the demo you have provided doesn’t.

In general any weird results that you are getting will be because marks is being stored as a string so MIN(marks) will be bringing back the earliest in alphabetical order though.

For example HAVING MIN(marks) > 45 will also bring back 5, 6, 7, 8 and 9