I have mysql table as follows:
|id | subject | link | week_number
------------------------------------
| 1 | ABC | link1 | week-1
| 2 | DEF | link2 | week-2
| 3 | GHI | link3 | week-3
------------------------------------
Now I want To show week-1 record to user for one week after login and from his registration date as initial date for week counting....
then in next week, week-1 and week-2 should be visible,
then in next week, week-1, week-2 and week-3 records should be visible.
I am completely blank...so didn't tried any code....
your help or guideline appreciated...
If you have a registration date, just make your live easier and change the column week_number to days_after_reg - and the values to 7,14,21
Then you just need to compare this number with the current offset:
SELECT * from linktable WHERE `days_after_reg` <= datediff(Now(), UserRegistrationDate)
Either insert the user date with a variable, or "join" the tables.
Note that the join has no join condition here, so don't forget to filter on user-id (or name or something).
SELECT l.subject, l.link from linktable l cross join
users u WHERE `l.days_after_reg` <= datediff(Now(), u.registrationDate)
and u.id=5
Related
currently working on a web project and i need help. how can i display values from 2 different tables in the database to a page? i'm still new in programming...
these are the 2 tables from database
Table A
| NAME | AGE | ID |
bryan 19 001
Table B
| current balance | date balance updated |
200 january 22, 2015
...and i want all of these to display in my web(below):
| name: | bryan |
| age: | 19 |
| id: | 001 |
| balance: | 200 |
any help is appreciated, thanks...
First that you need to do is to add foreign key in the second table. You need a field that will be pointing to the ID field in the second table:
Table B:
| current balance | date balance updated | person_id
200 january 22, 2015 001
Now you can select data from both tables using LEFT JOIN statement:
SELECT a.name, a.age, a.id, b.balance
FROM table_a as a
LEFT JOIN table_b as b ON b.person_id = a.id
JOIN is very powerful and frequently used construction. Learn more about it: http://www.w3schools.com/sql/sql_join_left.asp
Database data:
id | account | date | random_data
1 | 1 | 01/01/2013 | qw
2 | 2 | 05/01/2013 | er
3 | 2 | 09/01/2013 | ty
4 | 1 | 05/01/2013 | ui
5 | 2 | 11/01/2013 | op
6 | 1 | 12/01/2013 | as
Hi, so let's say I want the records starting from 05/01/2013 - note that prev_date for the 1st row still shows an earlier date than 05/01 meaning that the whole table still needs to be searched.
Result data:
account | cur_date | random_data | prev_date | prev_rand_data
1 | 05/01/2013 | ui | 01/01/2013 | qw
1 | 12/01/2013 | as | 05/01/2013 | ui
2 | 05/01/2013 | er | null | null
2 | 09/01/2013 | ty | 05/01/2013 | er
2 | 11/01/2013 | op | 09/01/2013 | ty
So I'm not sure what is the best, most optimized query I could use for this. I'm not opposed to a php solution but not sure how much better that would be. Some ideas I've considered:
Some sort of join on the same table - not sure how though
Sub queries on the select -
select date as cur_date
, (select max(date)
from table
where date < cur_date
group by account)
as prev_date... - this seems like it could be incredibly intensive
Session variables - set a session variable on each row which will be the previous data for the next row e.g.
select date as cur_date
, #prev_date as prev_date
, #prev_date:=date...
Has anyone had any experience with a problem like this and was there a good solution? Are there any positives negatives with any of the ideas I have that could cause problems in the future?
I would use a combination of sql and application code. Since I am not a php programmer, I will only describe the logic to use for the application part.
First the query.
select account, date, random_data
from thetable
where date >= YourDateVariable
union
select account, date, random_data
from thetable join
(select account acc, max(date) maxdate
from thetable
where date <= YourDateVariable
group by account) x on account = acc and date = max(date)
where date <= YourDateVariable
order by account, date
For the application code, do this:
Set a variable called ThisAccount to 0.
Set a row counter variable to 0.
Create an empty 2D array
Start looping through your query results
Put the account value and random data into the first two columns
of the next available row of the array
Compare the account value to the value of the ThisAccount variable.
If they are the same, get the previous date and random data from
the previous row in the array.
Set the ThisAccount variable to the current account value.
Increment your row counter variable
End of loop.
I have currently got a PHP generated calendar displaying some holidays for users. This information is stored in a database, I.e holidays and users. I want a user to be able to select a department and then AJAX will load the holidays for users only in that department.
Here are two made up tables with the same fundamental structure:
Table users
+------------------------------------+
| User | Department |
|------------+-----------------------|
| Brian | Sales |
| Tony | Marketing |
| Carol | Marketing |
| Dave | Warehouse |
| Chris | Warehouse |
+------------------------------------+
Table holiday
+------------------------------------+
| ID | User |
|------------+-----------------------|
| 1 | Dave |
| 2 | Tony |
| 3 | Tony |
| 4 | Chris |
| 5 | Carol |
+------------------------------------+
My current query:
$getAllHols = $con->query("SELECT * FROM `holiday`");
So of course, this just gets all holiday. I'm knowledgable enough on PHP to get a list of users in a specific department and then use that in another query to get holidays for those users. But I don't want to do this. I'm thinking there MUST be a pure-SQL solution. So I need the query to get all records from holiday where the user is in the selected department, using the two tables.
I.E:
If I chose the department "Marketing", records 2, 3 and 5 would be returned. (Tony and Carol are in Marketing).
Very easy problem for an advanced SQL user, I'm sure, but not to me. Can anyone help? Thanks.
Try this.
SELECT * FROM users
LEFT JOIN holiday ON users.user = holiday.user
WHERE holiday.department = 'marketing'
As far as I got...
select user
from users inner join holiday
on users.user = holiday.user
where department = 'Marketing'
This would provide a distinct list of records from the Holiday table if there are any matching records from the Users table. This improves upon the option of joining the tables, as you would not have to worry about de-duping the resulting data.
select distinct h.id, h.user
from holiday h
where h.user in (select u.user
from user u
where u.department = 'Marketing')
;
I wish to update one table in my database, the data is from a php POST. (It is a page where multiple edits on rows can take place at once, then it processes them all at once after) and i want it so for each "row" or "loop", it builds a single query that can update all the rows at once.
What i want to do, is in the query, select data from two other tables.
E.g
Posted data:
- Task = "Check current Sponsors"
- User Assigned = "Dan"
- Start Meeting = "Mar 1st"
- Meetings Required = 2
And for User Assigned, i want it to basically do this query:
SELECT id FROM team WHERE fullname LIKE 'Dan'
And for the start meeting, i want it to do this query:
SELECT id FROM meetings WHERE starttime='".strtotime("Mar
1st")."'
-- strtotime() makes a unix timestamp from a string.
but i want it to do that for each "task" that gets submitted. (It is queued up via javascript and it sends them all into the same post request)
Anyone have any ideas on how to do this?
Thanks in advance
Table Structures:
Tasks:
id | startmid | length | task | uid | completed
1 | 2 | 1 | Check Sponsors | 1 | 0
Meetings: (Joined by startmid)
id | maintask | starttime | endtime
1 | Sponsors | 1330007400 | 1330012800
Team: (Joined by uid)
id | fullname | position | class | hidden
1 | Team | All Members | black | 0
2 | Dan S | Team Manager | green | 0
you can use the following construct:
UPDATE mytable( col1, col2 )
SELECT col1_val, col2_val
FROM someothertables
WHERE cond1 = cond1;
With PHP and MySQL I am trying to display items with most votes over a certain period of time (24 hour, 1 week, 1 year, etc). When someone votes on an item, a table records the user, item id, vote, and time, like so:
Table1
username | itemid | vote | time
asdf | 127 | 1 | 1306726126
asdf | 124 | -1 | 1306726123
bob | 127 | 1 | 1306726129
bob | 124 | 1 | 1306726123
Now, I have another table with item details.
Table2
itemid | name | category | date | etc
What I WANT to do is call a table to display all the data from table 2 for only items with votes in the last 24hours and sort it by the votes. This means I need to SUM votes with TIME < 24 hours, then RIGHT JOIN (?) to my other database? I don't know, I am having difficulty figuring out how I should go about doing this. Any suggestiongs?
Something like this should work.
SELECT SUM(Table1.vote) as votes, Table2.* FROM Table2
LEFT JOIN Table1 ON Table1.itemid=Table2.itemid
WHERE Table1.`time`>=DATE_SUB(Table1.`time`, INTERVAL 24 HOUR)
GROUP BY Table1.itemid
ORDER BY Table1.votes DESC