How to restrict user to upload only three images in a month using PHP/MySQL

Question

I am working on PHP. My question is How can restrict a user can upload only three images in a month.

My Mysql Database table --

CREATE TABLE `images`          


        

Answer 1

Consider the following...

CREATE TABLE my_table
(id SERIAL PRIMARY KEY
,user_id INT NOT NULL
,date DATE NOT NULL
);

INSERT INTO my_table (user_id,date)
SELECT 1
     , '2018-01-01'
  FROM (SELECT 1) x
  LEFT
  JOIN (SELECT user_id
             , DATE_FORMAT(date,'%Y-%m') ym
          FROM my_table
         GROUP
            BY user_id
             , ym
        HAVING COUNT(*) >=3
       ) y
    ON y.user_id = 1
   AND y.ym = DATE_FORMAT('2018-01-01','%Y-%m')
 WHERE y.user_id IS NULL;
 LIMIT 1;

SELECT * FROM my_table;
+----+---------+------------+
| id | user_id | date       |
+----+---------+------------+
|  1 |       1 | 2018-01-01 |
+----+---------+------------+

INSERT INTO my_table (user_id,date)
SELECT 1
     , '2018-01-02'
  FROM (SELECT 1) x
  LEFT
  JOIN (SELECT user_id
             , DATE_FORMAT(date,'%Y-%m') ym
          FROM my_table
         GROUP
            BY user_id
             , ym
        HAVING COUNT(*) >=3
       ) y
    ON y.user_id = 1
   AND y.ym = DATE_FORMAT('2018-01-02','%Y-%m')
 WHERE y.user_id IS NULL
 LIMIT 1;

SELECT * FROM my_table;
+----+---------+------------+
| id | user_id | date       |
+----+---------+------------+
|  1 |       1 | 2018-01-01 |
|  2 |       1 | 2018-01-02 |
+----+---------+------------+

INSERT INTO my_table (user_id,date)
SELECT 1
     , '2018-01-02'
  FROM (SELECT 1) x
  LEFT
  JOIN (SELECT user_id
             , DATE_FORMAT(date,'%Y-%m') ym
          FROM my_table
         GROUP
            BY user_id
             , ym
        HAVING COUNT(*) >=3
       ) y
    ON y.user_id = 1
   AND y.ym = DATE_FORMAT('2018-01-02','%Y-%m')
 WHERE y.user_id IS NULL
 LIMIT 1;
Query OK, 1 row affected (0.00 sec)

SELECT * FROM my_table;
+----+---------+------------+
| id | user_id | date       |
+----+---------+------------+
|  1 |       1 | 2018-01-01 |
|  2 |       1 | 2018-01-02 |
|  3 |       1 | 2018-01-02 |
+----+---------+------------+

INSERT INTO my_table (user_id,date)
SELECT 1
     , '2018-01-03'
  FROM (SELECT 1) x
  LEFT
  JOIN (SELECT user_id
             , DATE_FORMAT(date,'%Y-%m') ym
          FROM my_table
         GROUP
            BY user_id
             , ym
        HAVING COUNT(*) >=3
       ) y
    ON y.user_id = 1
   AND y.ym = DATE_FORMAT('2018-01-03','%Y-%m')
 WHERE y.user_id IS NULL
 LIMIT 1;
Query OK, 0 rows affected (0.00 sec)

SELECT * FROM my_table;
+----+---------+------------+
| id | user_id | date       |
+----+---------+------------+
|  1 |       1 | 2018-01-01 |
|  2 |       1 | 2018-01-02 |
|  3 |       1 | 2018-01-02 |
+----+---------+------------+

INSERT INTO my_table (user_id,date)
SELECT 1
     , '2018-02-03'
  FROM (SELECT 1) x
  LEFT
  JOIN (SELECT user_id
             , DATE_FORMAT(date,'%Y-%m') ym
          FROM my_table
         GROUP
            BY user_id
             , ym
        HAVING COUNT(*) >=3
       ) y
    ON y.user_id = 1
   AND y.ym = DATE_FORMAT('2018-02-03','%Y-%m')
 WHERE y.user_id IS NULL
 LIMIT 1;
Query OK, 1 row affected (0.00 sec)

SELECT * FROM my_table;
+----+---------+------------+
| id | user_id | date       |
+----+---------+------------+
|  1 |       1 | 2018-01-01 |
|  2 |       1 | 2018-01-02 |
|  3 |       1 | 2018-01-02 |
|  4 |       1 | 2018-02-03 |
+----+---------+------------+