Get Nth weekday of the month from a column with DATE records in MySQL


We need to find the weekday i.e. week 1 from date 1 to 7, week 2 from date 8 to 14, etc. To get the day, use DAY() function in MySQL. Set the conditions to get the weekday (number) using CASE statement.

Let us now see an example and create a table −

mysql> create table DemoTable
(
   AdmissionDate date
);
Query OK, 0 rows affected (0.63 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values('2019-09-12');
Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable values('2019-09-06');
Query OK, 1 row affected (0.16 sec)
mysql> insert into DemoTable values('2019-09-26');
Query OK, 1 row affected (0.22 sec)
mysql> insert into DemoTable values('2019-09-30');
Query OK, 1 row affected (0.14 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

This will produce the following output −

+---------------+
| AdmissionDate |
+---------------+
| 2019-09-12    |
| 2019-09-06    |
| 2019-09-26    |
| 2019-09-30    |
+---------------+
4 rows in set (0.00 sec)

Following is the query to get the weekday (number) of the month −

mysql> select
(
   CASE WHEN DAY(AdmissionDate) BETWEEN 1 AND 7 THEN 1
      WHEN DAY(AdmissionDate) BETWEEN 8 AND 14 THEN 2
      WHEN DAY(AdmissionDate) BETWEEN 15 AND 21 THEN 3
      WHEN DAY(AdmissionDate) BETWEEN 22 AND 28 THEN 4
   else 5
      end
) as NthWeekDayOfMonth
from DemoTable;

This will produce the following output −

+-------------------+
| NthWeekDayOfMonth |
+-------------------+
|                 2 |
|                 1 |
|                 4 |
|                 5 |
+-------------------+
4 rows in set (0.01 sec)
raja
Published on 07-Oct-2019 16:20:33
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