Get Weekday name from index number in MYSQL

Question

I have a table which stores 0-6 as weekday value, and I want to display weekday name. Eg if value is 0 , it will display Sunday , if value is 1 , it will display Monday , likewise. Is there any inbuilt MySQL function for getting day name from Index?

Thanks in Advance!!

Answer 1

As @Aliminator mentioned, you could use DAYNAME with a DATE .

However, if you don't want to change your schema, here is a nifty hack for you:

 SELECT DAYNAME(CONCAT("1970-09-2", dayIndex)) FROM your_table;

This is based on the fact that 1970-09-20 was a Sunday, the 21st was a Monday, and so on.

Answer 2

DAYNAME( date_value ) is available in MySql; however, this takes a date, not an int. So if you have the date available, you can just use DAYNAME(CURDATE()) , DAYNAME('2014-01-07') , etc.

If all you have available is the int representing the weekday, then a CASE statement might be your best bet.

CASE WHEN 0 THEN 'Sunday' WHEN 1 THEN 'Monday' ..... ELSE '' END

Answer 3

Method 1:

Use a CASE expression.

Query

select *,
case when weekid = 0 then 'Sunday'
when weekid = 1 then 'Monday'
when weekid = 2 then 'Tuesday'
when weekid = 3 then 'Wednesday'
when weekid = 4 then 'Thursday'
when weekid = 5 then 'Friday'
when weekid = 6 then 'Saturday'
else null end as WeekName
from your_table;

Method 2:

You can create a table for storing the week names and select it using JOIN .

Table weekName

create table tblWeekName
(
    id int,
    weekName varchar(20)
);

insert into tblWeekName values
(0,'Sunday'),(1,'Monday'),(2,'Tuesday'),
(3,'Wednesday'),(4,'Thursday'),(5,'Friday'),(6,'Saturday');

Then use the following query to select the weekname.

select t1.*,
t2.weekName 
from your_table t1
join tblWeekName t2
on t1.weekid = t2.id;

Answer 4

There is a reduced variant of previous answers - you can write one time your name of column in CASE statement to reduce length of your code.

case tt.start_day_of_week 
when 0 then 'Sunday'
when 1 then 'Monday'
when 2 then 'Tuesday'
when 3 then 'Wednesday'
when 4 then 'Thursday'
when 5 then 'Friday'
when 6 then 'Saturday'
else null end

Answer 5

I looked through the MySql 5.5 documentation and there is a function when selecting called DayName() that you may be able to use. The down side is that you will need to use a DateTime variable, not an int.

https://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_dayname

I suggest changing your schema to take a DateTime so you can use DayName() and other built-in functions.

Answer 6

Are you sure that you really need to store the name of the weekday? If you need to get the week day for the stored date try DATE_FORMAT(date,format) with '%W' or '%w' format parameter. See here