pinal kalal pinal kalal - 5 months ago 10
SQL Question

Left Outer Join (MySQL) Issues, what's wrong with this query?

I am having five tables in mySQL and i am working on student fees module but i am having some problems on query so i am unable to get appropriate result so please help me I would greatly appreciate it if you kindly give me some feedback on this Query.

1.a )class_details Table Create

CREATE TABLE `class_details`
(`class_id_pk` int(11) NOT NULL AUTO_INCREMENT
,`class_name`varchar(200) NOT NULL
,`session` varchar(50) DEFAULT NULL
,`class_status` varchar(50) DEFAULT NULL
,PRIMARY KEY (`class_id_pk`)
,UNIQUE KEY `UNIQUE` (`class_name`,`session`)) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=latin1;


1.b) class_details Insert

insert into `class_details`
(`class_id_pk`,`class_name`,`session`,`class_status`)
VALUES
(1,'1st','2016-2017',NULL)
,(2,'2nd','2016-2017',NULL)
,(3,'3rd','2016-2017',NULL);


2.a) feedetails Table Create

CREATE TABLE `feedetails`
(`section_id_fk` int(50) NOT NULL
,`fees` varchar(30) DEFAULT NULL
,PRIMARY KEY (`section_id_fk`)) ENGINE=InnoDB DEFAULT CHARSET=latin1;


2.b) feedetails Insert

insert into `feedetails`(`section_id_fk`,`fees`)
values
(1,'1000')
,(2,'2000')
,(3,'3000')
,(4,'4000')
,(5,'5000')
,(6,'6000');


3.a) section_details Create

CREATE TABLE `section_details`
(`section_id_pk` int(11) NOT NULL AUTO_INCREMENT
,`class_id_fk` int(11) NOT NULL
,`section_name` varchar(50) NOT NULL
,`section_status` varchar(50) DEFAULT NULL
,PRIMARY KEY (`section_id_pk`,`class_id_fk`,`section_name`)
,UNIQUE KEY `UNIQUE` (`class_id_fk`,`section_name`)
,CONSTRAINT `FK_section_details` FOREIGN KEY (`class_id_fk`) REFERENCES `class_details` (`class_id_pk`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=latin1;


3.b) section_details Insert

insert into `section_details` (`section_id_pk`,`class_id_fk`,`section_name`,`section_status`)
values
(1,1,'A',NULL)
,(2,2,'A',NULL)
,(3,3,'A',NULL);


4.a) student_fee

CREATE TABLE `student_fee`
( `sr_no` int(200) NOT NULL AUTO_INCREMENT
,`scholar_no`int(50) NOT NULL
,`paid_amount` int(200) DEFAULT NULL
,`due_amount` int(200) DEFAULT NULL
,`fee_date` date DEFAULT NULL
,`section_id_fk` int(50) DEFAULT NULL
,PRIMARY KEY (`sr_no`)
,KEY `FK_student_fee`(`section_id_fk`)
,CONSTRAINT `FK_student_fee` FOREIGN KEY (`section_id_fk`) REFERENCES `section_details` (`section_id_pk`) ON DELETE CASCADE ON UPDATE CASCADE ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1;


4.b) student_fee Insert

insert into student_fee` (`sr_no`,`scholar_no`,`paid_amount`,`due_amount`,`fee_date`,`section_id_fk`)
values
(3,5,800,200,'2016-06-16',1)
,(4,29,1000,0,'2016-06-16',1)
,(5,5,200,0,'2016-06-16',1);


5.a) student_details Create

CREATE TABLE `student_details`
(`scholar_no` int(30) NOT NULL
,`fname` varchar(30) DEFAULT NULL
,`lname` varchar(30) DEFAULT NULL
,`stu_class` varchar(30) DEFAULT NULL
,`rte` varchar(30) DEFAULT NULL
,`active` varbinary(10) DEFAULT NULL
,PRIMARY KEY (`scholar_no`)) ENGINE=InnoDB DEFAULT CHARSET=latin1;


5.b) student_details Insert

insert into `student_details` (`scholar_no`,`fname`,`lname`,`stu_class`,`rte`,`active`)
values
(5,'KP','PK','1','N','y')
,(29,'Abc','Xyz','1','N','y');


Above i have mentioned all the Table details which are used for this query.
First time in student_details table stu_class=1 and the fees will be 1000. when i insert some values in student_fee and use my query then the result is correct but when i insert some of amount to another student in student_fee then the query added the paid amount to the same student which is not correct i want to show the inserted fees for those student who actually inserted..

SELECT
student_details.scholar_no
,student_details.fname
,student_details.lname
,student_details.stu_class
,feedetails.fees
,class_name
,section_name
,IF(sssf.paid_amount IS NULL,0,sssf.paid_amount) AS paid_amount
FROM
(student_details
LEFT OUTER JOIN feedetails
ON student_details.stu_class = feedetails.section_id_fk
)
LEFT OUTER JOIN
(SELECT
scholar
, SUM(pa) AS paid_amount
, SUM(pva) AS prev_paid_amount
,SUM(da) AS due_amount
, SUM(dva) AS prev_due_amount
,section_id_fk
,fee_date
,stu_class
FROM
(SELECT
scholar
,CASE WHEN section_id_fk = stu_class THEN paid_amount ELSE 0 END AS pa
,CASE WHEN section_id_fk != stu_class THEN paid_amount ELSE 0 END AS pva
,CASE WHEN section_id_fk = stu_class THEN due_amount ELSE 0 END AS da
,CASE WHEN section_id_fk != stu_class THEN due_amount ELSE 0 END AS dva
,due_amount
,paid_amount
,section_id_fk
,fee_date
,stu_class
FROM
(SELECT
scholar
,due_amount
,SUM(paid_amount) AS paid_amount
,section_id_fk
,fee_date
FROM
(SELECT
student_fee.due_amount AS due_amount
,student_fee.paid_amount AS paid_amount
,student_fee.scholar_no AS scholar
,section_id_fk
,fee_date
FROM student_fee
ORDER BY STR_TO_DATE(fee_date,'%Y-%m-%d')DESC
) AS kkk
GROUP BY kkk.scholar,section_id_fk ORDER BY scholar
) AS k
LEFT OUTER JOIN student_details sd
ON k.scholar = sd.scholar_no
) AS lk
) AS sssf
ON student_details.scholar_no = sssf.scholar
LEFT OUTER JOIN
(SELECT *
FROM section_details AS sd
LEFT OUTER JOIN class_details cd
ON sd.class_id_fk = cd.class_id_pk
) AS sc
ON student_details.stu_class = sc.section_id_pk
WHERE student_details.active = 'y' AND rte = 'N'

Answer

Check the below SQL, I had a quick fix. If does not solve please explain your problem a bit more.

SELECT 
student_details.scholar_no
,student_details.fname
,student_details.lname
,student_details.stu_class
,feedetails.fees
,class_name
,section_name
,IF(sssf.paid_amount IS NULL,0,sssf.paid_amount) AS paid_amount 
FROM 
    (student_details 
    LEFT OUTER JOIN feedetails 
        ON student_details.stu_class = feedetails.section_id_fk
    ) 
LEFT OUTER JOIN 
    (SELECT 
    scholar
    , SUM(pa) AS paid_amount
    , SUM(pva) AS prev_paid_amount
    ,SUM(da) AS due_amount
    , SUM(dva) AS prev_due_amount
    ,section_id_fk
    ,fee_date
    ,stu_class 
    FROM 
        (SELECT 
        scholar
        ,CASE WHEN section_id_fk = stu_class THEN paid_amount ELSE 0 END AS pa
        ,CASE WHEN section_id_fk != stu_class THEN paid_amount ELSE 0 END AS pva
        ,CASE WHEN section_id_fk = stu_class THEN due_amount ELSE 0 END AS da
        ,CASE WHEN section_id_fk != stu_class THEN due_amount ELSE 0 END AS dva
        ,due_amount
        ,paid_amount
        ,section_id_fk
        ,fee_date
        ,stu_class 
        FROM 
            (SELECT 
            scholar
            ,due_amount
            ,SUM(paid_amount) AS paid_amount
            ,section_id_fk
            ,fee_date 
            FROM 
                (SELECT 
                student_fee.due_amount AS due_amount
                ,student_fee.paid_amount AS paid_amount
                ,student_fee.scholar_no AS scholar
                ,section_id_fk
                ,fee_date 
                FROM student_fee 
                ORDER BY STR_TO_DATE(fee_date,'%Y-%m-%d')DESC
                ) AS kkk 
            GROUP BY kkk.scholar,section_id_fk ORDER BY scholar
        ) AS k 
        LEFT OUTER JOIN student_details sd 
            ON k.scholar = sd.scholar_no
    ) AS lk
    group by scholar
) AS sssf 
ON student_details.scholar_no = sssf.scholar 
LEFT OUTER JOIN 
    (SELECT * 
    FROM section_details AS sd 
    LEFT OUTER JOIN class_details cd 
        ON sd.class_id_fk = cd.class_id_pk
    ) AS sc 
ON student_details.stu_class = sc.section_id_pk 
WHERE student_details.active = 'y' AND rte = 'N'