How to join 4 tables in mysql PDO?
I have 4 tables as below:
1) courses
| ID - > Primary Key | Name
-------------------------------
| 1 | Course 1
| 2 | Course 2
| 3 | Course 3
2) countries
| IDPrimary Key | Name
-------------------------------
| 1 | Country 1
| 2 | Country 2
| 3 | Course 3
3) universities
| ID - > Primary Key | Name | country_id
---------------------------------------------------
| 1 | University 1 | 1
| 2 | University 2 | 1
| 3 | University 3 | 3
4) university_courses
| ID - > Primary Key | university_id | course_id
----------------------------------------------
| 1 | 1 | 2
| 2 | 3 | 2
| 3 | 3 | 3
Now, I need to create one REST API in core PHP for android app in that I will get two parameters country_id
and course_id
. Both will contain multiple values like country_id = "3,4,5"
and course_id = "1,6,8"
.
I have to response all the related universities according to the country and course.
I have tried below query but i am not getting desired output so please help me if anyone have idea for my problem.
SELECT *
FROM universities
LEFT JOIN countries ON countries.id = universities.country_id
LEFT JOIN university_courses ON universiity_courses.university_id = universities.id
LEFT JOIN courses ON courses.id = university_courses.course_id
WHERE FIND_IN_SET(universities.country_id, ?)
AND FIND_IN_SET(university_courses.course_id, ?)
If course_id = 1,2
and country_id = 2,3
, my desired output should be:
| university_id |
| 3 |
php mysql pdo
|
show 2 more comments
I have 4 tables as below:
1) courses
| ID - > Primary Key | Name
-------------------------------
| 1 | Course 1
| 2 | Course 2
| 3 | Course 3
2) countries
| IDPrimary Key | Name
-------------------------------
| 1 | Country 1
| 2 | Country 2
| 3 | Course 3
3) universities
| ID - > Primary Key | Name | country_id
---------------------------------------------------
| 1 | University 1 | 1
| 2 | University 2 | 1
| 3 | University 3 | 3
4) university_courses
| ID - > Primary Key | university_id | course_id
----------------------------------------------
| 1 | 1 | 2
| 2 | 3 | 2
| 3 | 3 | 3
Now, I need to create one REST API in core PHP for android app in that I will get two parameters country_id
and course_id
. Both will contain multiple values like country_id = "3,4,5"
and course_id = "1,6,8"
.
I have to response all the related universities according to the country and course.
I have tried below query but i am not getting desired output so please help me if anyone have idea for my problem.
SELECT *
FROM universities
LEFT JOIN countries ON countries.id = universities.country_id
LEFT JOIN university_courses ON universiity_courses.university_id = universities.id
LEFT JOIN courses ON courses.id = university_courses.course_id
WHERE FIND_IN_SET(universities.country_id, ?)
AND FIND_IN_SET(university_courses.course_id, ?)
If course_id = 1,2
and country_id = 2,3
, my desired output should be:
| university_id |
| 3 |
php mysql pdo
1
You want to use the IN() operator
– Raymond Nijland
Jan 1 at 12:42
Any way we can use, but need proper output.
– Jk7
Jan 1 at 12:44
You are using LEFT JOIN which is wrong you need to use a INNER JOIN to get the related relations. Also you JOiN to much tables then you could. You only have to need to JOIN between university_courses and the universities to get the required results
– Raymond Nijland
Jan 1 at 12:52
Okay, now above issue is partially solved.
– Jk7
Jan 1 at 13:12
But now i m getting same university twice, ifcourse_id=2,3
. So in shortGroup by
is not working.
– Jk7
Jan 1 at 13:15
|
show 2 more comments
I have 4 tables as below:
1) courses
| ID - > Primary Key | Name
-------------------------------
| 1 | Course 1
| 2 | Course 2
| 3 | Course 3
2) countries
| IDPrimary Key | Name
-------------------------------
| 1 | Country 1
| 2 | Country 2
| 3 | Course 3
3) universities
| ID - > Primary Key | Name | country_id
---------------------------------------------------
| 1 | University 1 | 1
| 2 | University 2 | 1
| 3 | University 3 | 3
4) university_courses
| ID - > Primary Key | university_id | course_id
----------------------------------------------
| 1 | 1 | 2
| 2 | 3 | 2
| 3 | 3 | 3
Now, I need to create one REST API in core PHP for android app in that I will get two parameters country_id
and course_id
. Both will contain multiple values like country_id = "3,4,5"
and course_id = "1,6,8"
.
I have to response all the related universities according to the country and course.
I have tried below query but i am not getting desired output so please help me if anyone have idea for my problem.
SELECT *
FROM universities
LEFT JOIN countries ON countries.id = universities.country_id
LEFT JOIN university_courses ON universiity_courses.university_id = universities.id
LEFT JOIN courses ON courses.id = university_courses.course_id
WHERE FIND_IN_SET(universities.country_id, ?)
AND FIND_IN_SET(university_courses.course_id, ?)
If course_id = 1,2
and country_id = 2,3
, my desired output should be:
| university_id |
| 3 |
php mysql pdo
I have 4 tables as below:
1) courses
| ID - > Primary Key | Name
-------------------------------
| 1 | Course 1
| 2 | Course 2
| 3 | Course 3
2) countries
| IDPrimary Key | Name
-------------------------------
| 1 | Country 1
| 2 | Country 2
| 3 | Course 3
3) universities
| ID - > Primary Key | Name | country_id
---------------------------------------------------
| 1 | University 1 | 1
| 2 | University 2 | 1
| 3 | University 3 | 3
4) university_courses
| ID - > Primary Key | university_id | course_id
----------------------------------------------
| 1 | 1 | 2
| 2 | 3 | 2
| 3 | 3 | 3
Now, I need to create one REST API in core PHP for android app in that I will get two parameters country_id
and course_id
. Both will contain multiple values like country_id = "3,4,5"
and course_id = "1,6,8"
.
I have to response all the related universities according to the country and course.
I have tried below query but i am not getting desired output so please help me if anyone have idea for my problem.
SELECT *
FROM universities
LEFT JOIN countries ON countries.id = universities.country_id
LEFT JOIN university_courses ON universiity_courses.university_id = universities.id
LEFT JOIN courses ON courses.id = university_courses.course_id
WHERE FIND_IN_SET(universities.country_id, ?)
AND FIND_IN_SET(university_courses.course_id, ?)
If course_id = 1,2
and country_id = 2,3
, my desired output should be:
| university_id |
| 3 |
php mysql pdo
php mysql pdo
edited Jan 1 at 13:24
RiggsFolly
71.1k1864111
71.1k1864111
asked Jan 1 at 12:38
Jk7Jk7
142
142
1
You want to use the IN() operator
– Raymond Nijland
Jan 1 at 12:42
Any way we can use, but need proper output.
– Jk7
Jan 1 at 12:44
You are using LEFT JOIN which is wrong you need to use a INNER JOIN to get the related relations. Also you JOiN to much tables then you could. You only have to need to JOIN between university_courses and the universities to get the required results
– Raymond Nijland
Jan 1 at 12:52
Okay, now above issue is partially solved.
– Jk7
Jan 1 at 13:12
But now i m getting same university twice, ifcourse_id=2,3
. So in shortGroup by
is not working.
– Jk7
Jan 1 at 13:15
|
show 2 more comments
1
You want to use the IN() operator
– Raymond Nijland
Jan 1 at 12:42
Any way we can use, but need proper output.
– Jk7
Jan 1 at 12:44
You are using LEFT JOIN which is wrong you need to use a INNER JOIN to get the related relations. Also you JOiN to much tables then you could. You only have to need to JOIN between university_courses and the universities to get the required results
– Raymond Nijland
Jan 1 at 12:52
Okay, now above issue is partially solved.
– Jk7
Jan 1 at 13:12
But now i m getting same university twice, ifcourse_id=2,3
. So in shortGroup by
is not working.
– Jk7
Jan 1 at 13:15
1
1
You want to use the IN() operator
– Raymond Nijland
Jan 1 at 12:42
You want to use the IN() operator
– Raymond Nijland
Jan 1 at 12:42
Any way we can use, but need proper output.
– Jk7
Jan 1 at 12:44
Any way we can use, but need proper output.
– Jk7
Jan 1 at 12:44
You are using LEFT JOIN which is wrong you need to use a INNER JOIN to get the related relations. Also you JOiN to much tables then you could. You only have to need to JOIN between university_courses and the universities to get the required results
– Raymond Nijland
Jan 1 at 12:52
You are using LEFT JOIN which is wrong you need to use a INNER JOIN to get the related relations. Also you JOiN to much tables then you could. You only have to need to JOIN between university_courses and the universities to get the required results
– Raymond Nijland
Jan 1 at 12:52
Okay, now above issue is partially solved.
– Jk7
Jan 1 at 13:12
Okay, now above issue is partially solved.
– Jk7
Jan 1 at 13:12
But now i m getting same university twice, if
course_id=2,3
. So in short Group by
is not working.– Jk7
Jan 1 at 13:15
But now i m getting same university twice, if
course_id=2,3
. So in short Group by
is not working.– Jk7
Jan 1 at 13:15
|
show 2 more comments
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1
You want to use the IN() operator
– Raymond Nijland
Jan 1 at 12:42
Any way we can use, but need proper output.
– Jk7
Jan 1 at 12:44
You are using LEFT JOIN which is wrong you need to use a INNER JOIN to get the related relations. Also you JOiN to much tables then you could. You only have to need to JOIN between university_courses and the universities to get the required results
– Raymond Nijland
Jan 1 at 12:52
Okay, now above issue is partially solved.
– Jk7
Jan 1 at 13:12
But now i m getting same university twice, if
course_id=2,3
. So in shortGroup by
is not working.– Jk7
Jan 1 at 13:15