I have 3 tables in my mysql database: student, progress and subject
. When I try to select data:
SELECT progress.id, progress.mark, subject.pname FROM progress, subject WHERE progress.id_student = 1;
I get the following table:
id mark pname
1 5 Math
1 5 Physics
Table progress I only have one entry:
id mark id_student id_subject
1 5 1 1
How can I get student progress by student_id
?
CREATE DATABASE students;
USE students;
CREATE TABLE student (
id int NOT NULL AUTO_INCREMENT,
name varchar(100) NOT NULL,
address varchar(60) NOT NULL,
byear int NOT NULL,
eyear int NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE subject (
id int NOT NULL AUTO_INCREMENT,
pname varchar(20) NOT NULL,
PRIMARY KEY (id)
);
CREATE TABLE progress (
id int NOT NULL AUTO_INCREMENT,
mark int NOT NULL,
id_student int NOT NULL,
id_subject int NOT NULL,
PRIMARY KEY (id),
FOREIGN KEY (id) REFERENCES student (id),
FOREIGN KEY (id) REFERENCES subject (id)
);
SELECT progress.id, progress.mark, subject.pname
FROM progress LEFT OUTER JOIN subject ON (progress.id_subject= subject.id)
WHERE progress.id_student = 1;
Try
SELECT progress.id, progress.mark, subject.pname
FROM progress, subject
WHERE progress.id_student = 1 AND progress.id_subject = subject.id;
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