Find if a date is in date range using MySQL

Question

Hi I have following values stored in MySQL table:

--- ------------------------     -------------------
Id | StartDate (VARCHAR (20))  | EndDate(VARCHAR(20))
--- ------------------------     -------------------
1  | 03-04-2017                | 18-04-2017

I am using the following SQL to find if the date is within the StartDate and EndDate:

SELECT 
(date_format(str_to_date('03-04-2017','%d-%m-%Y'),'%d-%m-%Y') >= StartDate 
AND 
date_format(str_to_date('03-04-2017','%d-%m-%Y'),'%d-%m-%Y') <= EndDate) AS 
valid 
FROM holiday

My issue is it that when I execute the query and provide 03-04-2017 it returns 1 but also returns 1 when I provide 03-05-2017.

Could someone please highlight what is wrong in this query?

Answer 1

Use a query like this:

SELECT *
FROM holiday
WHERE
    STR_TO_DATE(StartDate,'%d-%m-%Y')
BETWEEN 
    str_to_date('03-04-2017','%d-%m-%Y')
AND
    str_to_date('03-04-2017','%d-%m-%Y');

sample

mysql> SELECT IF(STR_TO_DATE('11-04-2017','%d-%m-%Y')
    ->             BETWEEN
    ->                 str_to_date('03-04-2017','%d-%m-%Y')
    ->             AND
    ->                 str_to_date('10-04-2017','%d-%m-%Y')
    ->
    -> ,'YES','NO') AS ANSWER;
+--------+
| ANSWER |
+--------+
| NO     |
+--------+
1 row in set (0,00 sec)

mysql> SELECT IF(STR_TO_DATE('04-04-2017','%d-%m-%Y')
    ->             BETWEEN
    ->                 str_to_date('03-04-2017','%d-%m-%Y')
    ->             AND
    ->                 str_to_date('10-04-2017','%d-%m-%Y')
    ->
    -> ,'YES','NO') AS ANSWER;
+--------+
| ANSWER |
+--------+
| YES    |
+--------+
1 row in set (0,01 sec)

mysql>

Answer 2

You can use BETWEEN operator to compare the dates, eg:

SELECT * 
FROM `table` 
WHERE '2017-04-03' BETWEEN start_date AND end_date;

Update

If the dates are stored as varchar then you need to convert it to date before comparing, eg:

SELECT * 
FROM table 
WHERE '2017-04-03' BETWEEN STR_TO_DATE(start_date, '%d-%m-%Y') AND STR_TO_DATE(end_date, '%d-%m-%Y');

Here's the SQL Fiddle .

Answer 3

All other answers are good for your question but in my opinion you should convert your database.

It's only sane option.

Using dates in weird VARCHAR format will have big impact in future. Not only it impacts perfomances of your tables right now but you are missing whole MySQL date API ecosystem because of it.

1. Add temporary columns let's say tmp_start_time DATE
2. Fill them with dates UPDATE holiday SET tmp_start_time = str_to_date(start_time,'%d-%m-%Y')
3. Drop old varchar keys in table
4. Add same keys but as DATE
5. Update them UPDATE holiday SET start_time = tmp_start_time

From now on you would be able to use BETWEEN as everyone else without str_to_date

---

I just found your comment

unfortunately I cannot change schema

ask yourself twice: are you sure?