How can we use count() with conditional sql in select() of laravel? - php

Question

I have two tables as shown below. I am using Laravel DB method to join this table. But I am not getting how can I get the count of marks of students as per failed or passed. 0-failed 1-passed.
Expected result:
1. Student Name
2. Student Id,
3. Count of failed based on student Id as count_failed
4. Total Marks based on student Id as total_marks
table students
`+----+-----------+
| id | name |
+----+-----------+
| 1 | John Doe |
| 2 | Mark P |
| 3 | Pen Henry |
+----+-----------+`
table students_marks:
+----+------------+-------+-----------+
| id | student_id | marks |is_failed |
+----+------------+-------+-----------+
| 1 | 1 | 55 | 0 |
| 2 | 2 | 44 | 1 |
| 3 | 1 | 11 | 1 |
| 4 | 2 | 10 | 0 |
| 5 | 2 | 11 | 1 |
| 6 | 2 | 20 | 0 |
+----+------------+-------+-----------+
Below is query which I used:
$users = DB::table('users')
->join('contacts', 'students.id', '=', 'students_marks.user_id')
->select('student.*')
->get();
I am unable to get how can we use count() with conditional SQL in select() of laravel?

Answer 1

Use conditional aggregation:
$users = DB::table('students s')
->leftJoin('students_mark sm', 's.id', '=', 'sm.user_id')
->groupBy('sm.id')
->select(DB::raw('s.id, s.name, SUM(sm.is_failed) AS num_failed, COUNT(sm.user_id) AS total_cnt'))
->get();
This corresponds to the following raw MySQL query:
SELECT
s.id,
s.name,
SUM(sm.is_failed) AS num_failed,
COUNT(sm.user_id) AS total_cnt
FROM students s
LEFT JOIN students_marks sm
ON s.id = sm.user_id
GROUP BY
s.id;
Note: It is acceptable in ANSI SQL to select the name field in the above GROUP BY query assuming that student#id is the primary key column for that table. If the above query gives an ONLY_FULL_GROUP_BY error, then simply add s.name to the GROUP BY clause.

Answer 2

$users = DB::table('users')
->join('contacts', 'students.id', '=', 'students_marks.user_id')
->select('student.*', DB::raw("count(students_marks.is_failed) as count")))
->where('status', '=', 0)
->get();
Try this.
If this is not clear or doesn't work refer this

Answer 3

Try this code snippet
$table = DB::table('students_marks');
$table = $table->select(
\DB::raw('SUM(if(is_failed = '0', 1, 0)) AS failed'),
\DB::raw('SUM(if(is_failed = '1', 1, 0)) AS passed'),
\DB::raw('SUM(marks) AS total'));
$table = $table->Join('students', 'students.id', '=', 'students_marks.student_id');
$table = $table->get();

Answer 4

Try this
$users = DB::table('students s')
->leftJoin('students_mark sm', 's.id', '=', 'sm.student_id')
->groupBy('s.id','s.name')
->selectRaw("s.id,s.name,SUM(sm.is_failed) AS count_failed,SUM(sm.marks) as total_marks")
->get();