hi, i was solving same problem before month and i finished it by this way:
select dayname("2003-11-12"), yearweek("2003-11-12"),ADDDATE('2003-01-06',
INTERVAL 7*(WEEK('2003-11-12')-1) DAY),ADDDATE('2003-01-06', INTERVAL
7*(WEEK('2003-11-12')-1)+6 DAY);
but there is constant '2003-01-06', that's date of first Monday (Monday
because i'm Czech) of first week in a year.
There is a lot of ways to number weeks, see WEEK() function .
I think it's impossible to get this date (the date of first day of first
week) just in query, maybe you can write your own function ;))
But if you are using something like PHP etc., you can simply go throw 6 days
before and after your date, and simply check while the week number is same
like weeknumber you got from mysql.
I hope that it helps you little.
`WEEK(date [,mode])'
The function returns the week number for `date'. The two-argument
form of `WEEK()' allows you to specify whether the week starts on
Sunday or Monday and whether the return value should be in the
range 0-53 or 1-52. When `mode' argument is omitted the value of a
`default_week_format' server variable (or 0 in MySQL 4.0 or
earlier) is assumed. *Note SET OPTION::.
The following table demonstrates how the `mode' argument works:
*Value* *Meaning*
0 Week starts on Sunday; return value range is 0 to 53;
week 1 is the first week that starts in this year
1 Week starts on Monday; return value range is 0 to 53;
week 1 is the first week that has more than 3 days in
this year
2 Week starts on Sunday; return value range is 1 to 53;
week 1 is the first week that starts in this year
3 Week starts on Monday; return value range is 1 to 53;
week 1 is the first week that has more than 3 days in
this year
4 Week starts on Sunday; return value range is 0 to 53;
week 1 is the first week that has more than 3 days in
this year
5 Week starts on Monday; return value range is 0 to 53;
week 1 is the first week that starts in this year
6 Week starts on Sunday; return value range is 1 to 53;
week 1 is the first week that has more than 3 days in
this year
7 Week starts on Monday; return value range is 1 to 53;
week 1 is the first week that starts in this year
The `mode' value of 3 can be used as of MySQL 4.0.5. The `mode'
value of 4 and above can be used as of MySQL 4.0.17.
----- Original Message -----
From: "Trevor Smith" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, January 26, 2004 12:56 PM
Subject: yearweek() result back to date format?
> How can I use the output string of the yearweek() function
> (for example, "200346" below):
>
> mysql> select dayname("2003-11-12"), yearweek("2003-11-12");
> +-----------------------+------------------------+
> | dayname("2003-11-12") | yearweek("2003-11-12") |
> +-----------------------+------------------------+
> | Wednesday | 200346 |
> +-----------------------+------------------------+
> 1 row in set (0.00 sec)
>
> to extract the start and end dates for that week (for example,
"2003-11-09"
> and "2003-11-15" above)?
>
> I'm using server v3.23.
>
> --
> Trevor Smith | [EMAIL PROTECTED]
>
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> MySQL General Mailing List
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>
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