I have a project with a table (figure A) and display all the records to the web browser with pagination something like this:
How can I do so that the cumulative each page of the 'Amount' counted correctly in the last page?
I've try by looping but it give me result in page 1 = 21, page 2 = 24, and so on. Of course this is wrong.
Need help. Thank You
Make a separate query for the total amount:
SELECT SUM(Amount) AS TotalAmount
FROM tablename
Then display it in the end of the pages, outside of the loop.
Well MySQL WITH ROLLUP is used for this. This adds an extra row at last and can be used with aggregate functions.
SELECT
id,
IFNULL(stock,'Total') AS `stock`,
SUM(amount) AS Total
FROM board
GROUP BY stock WITH ROLLUP
You can add limit in this query according to your requirements
SQL Fiddle Example
With Limit
SQL Fiddle Example
Related
So I am trying to create a query that shows the list of all the dates customers came in to order food. However, since there were multiple customers for a particular day and thats how the values have been stored in the table, whenever I turn the following query:-
SELECT DateOfEntry FROM KFC;
Although it works and I see all the details, I dont want the same date value to repeat. For example if Two customers A and B, came in on 11/11/17 to order food, I would get the result of the above mentioned query with two records of same date. I dont want the same dates to repeat. What do I do?
I know DISTINCT works but the problem is, I am creating a php page where admins can check the list of all the users who came in on a particular day. So I am using the select and option methods of HTML to select a date which then shows the list of the users who made an entry that day. With this code, only one record is shown
Try:
SELECT DISTINCT DateOfEntry FROM KFC;
Try :
SELECT DISTINCT DateOfEntry FROM KFC;
or this
SELECT DateOfEntry FROM KFC
GROUP BY DateOfEntry;
So I have the following query, which I use it to get some analytics stats.
SELECT count(*) as total,CONCAT(YEAR(created),'-',MONTH(created),'-',DAY(created))
as date_only FROM logs where action = 'banner view'
and created BETWEEN '2015-07-03 21:03'
AND '2017-08-02 21:03' group by date_only order by created asc
This works, and it gives me this:
So what I actually need is, the total count of the rows in this case is 20, this is a dummy example, but I need to use this count to check before showing the stats if the data is too big to be displayed on a graphic.
Can this be achieved?
//LE
So the process will be like this:
1. Get a count of the total rows, if the count of rows is smaller than X(number will be in config and it will be a basic if statement), then go ahread and run the above query.
More info:
I actually use this query to display the stats, I just need to adapt it in order to show the total count rows
So the result of thquery should be
total | 20 in this case
I think you would want to use a derived table. Just wrap your original query in parenthesis after the FROM and then give the derived table an alias (in this case tmp). Like so:
SELECT count(*) FROM (
SELECT count(*) as total,CONCAT(YEAR(created),'-',MONTH(created),'-',DAY(created))
as date_only FROM logs where action = 'banner view'
and created BETWEEN '2015-07-03 21:03'
AND '2017-08-02 21:03' group by date_only order by created asc
) as tmp;
If I understand what you want to do correctly, this should work. It should return the actual number of results from your original query.
What's happening is that the results of the parenthesized query are getting used as a sort of virtual table to query against. The parenthesized query returns 20 rows, so the "virtual" table has 20 rows. The outer count(*) just counts how many rows there are in that virtual table.
Based on the PHP tag, I assume you are using PHP to send the queries to MySQL. If so, you can use mysqli_num_rows to get the answer.
If your query result is in $result then:
$total = mysqli_num_rows($result);
Slightly different syntax for Object Oriented style instead of procedural style.
The best part is you don't need an extra query. You perform the original query and get mysqli_num_rows as an extra without running another query. So you can figure out pagination or font size or whatever and then display without doing the query again.
This is an small query but works fine, and give me the total number of rows, you just need add your conditions.
SELECT COUNT(*) FROM table WHERE field LIKE '%condition%'
The group by I think you need to eliminated, becouse, this instead of count the records, divide in all your group by, example: records = 4, with group by you have
1
1
1
1
I hope this help you
You can try this way .
SELECT COUNT(*) FROM ( SELECT count(*) as total,CONCAT(YEAR(created),'-',MONTH(created),'-',DAY(created))
as date_only FROM logs where action = 'banner view'
and created BETWEEN '2015-07-03 21:03'
AND '2017-08-02 21:03' group by date_only HAVING total >=20 ) temp
Say I have a table with 1million rows. One column lists the "Group", and another lists "Sales". The Group #'s range from 1 to 100,000 such that each Group has about 10 Sales entries. I want to somehow summarize the data into 100,000 rows with the sum of Sales for each group rather than each individual sale.
My method so far has been to run a PHP loop from 1 to 100,000 where each iteration sends an SQL query to sum(Sales) WHERE Group=$i. Then I can either echo it into an html table, or insert it into a new SQL table. Problem is it takes hours this method.
Any tips on how I can improve this process? Is there a way to write this as a single SQL query that will massively increase speed? Thanks
Just try a GROUP BY:
SELECT `group`, sum(sales)
FROM your_table
GROUP BY `group`
Edit to include back ticks for group. Without them you will receive an error
You should always avoid a SQL query in a loop unless there's no other solution. In this case, you can grab all the fields at once and have them in an array and add them up in PHP that way.
I got a database that registers user actions and their geolocation.
Now I would like to fetch this data at the hand of the last action per user.
The table looks a bit like:
geoaction_id AUTO INCREMENT
geoaction_user
geoaction_creationdate (Y-m-d H:i:s)
geoaction_action
geoaction_lon
geoaction_lat
Now I would like to make a simple query that selects of all users the last item.
But LIMIT 0,1 just parses one row no matter what. (LOGICALLY!!)
Group by gives a little better result.
But how to get only the last item per user?
Try this, please provide the queries you have checked out so far, in order to assist you better.
SELECT geoaction_user, geoaction_action
FROM table-name
GROUP BY geoaction_user
ORDER BY geoaction_action DESC LIMIT 1
Working with sets:
SELECT
g.geoaction_user,
g.geoaction_action,
g.geoaction_creationdate,
g.geoaction_lat,
g.geoaction_lon
FROM
(
SELECT
geoaction_user,
MAX(geoaction_id) max_id
FROM
geoactions
GROUP BY geoaction_user
) s
JOIN
geoactions g
ON s.geoaction_user = g.geoaction_user
AND s.max_id = geoaction_id
The subquery generates a virtual table with the geoaction_id from the latest entry in the tabble for each user_id, then the table is joined to get the data belong to the latest id.
If you need to filter out some records place the where clause in the subquery
I have been working on try to create php web-based paging for our tables
which have over a million rows.
Based on what I have read, I have 3 options
retrieve all rows in resultset - not possiblefor me coz of the size
retrieve 1000 rows, store in temp table and create an iterator for
it and page through it - too many queries - too many inserts!!
run a query each time if someone opts page forward or backwards
Right now I am trying to get option 3 working.
I have the first page showing up as
"select * from accout order by acct fetch first 10 rows only"
Page next
"select * from account where acct>(last record) order by acct fetch
first 10 only"
page last record
"select * from account where acct=(select max(acct) from account)"
The problem is showing the previous page and i really would appreciate
help in this.
SELECT *
FROM (
SELECT
*,
ROW_NUMBER() OVER (ORDER BY acct) AS RowNum
FROM
account
) AS Data
WHERE
RowNum BETWEEN 100 AND 110;
First, you should get rid of the SELECT *. Select only the fields you need.
Place an index on acct, this will help the ROW_NUMBER() OVER (ORDER BY acct) construct.
Use a SELECT COUNT(*) FROM account to determine how many pages you will have.
Also read Fastest most/efficient way to do pagination with SQL searching DB2
The LIMIT..OFFSET solution is supported in DB2 10+.. For older versions, you have to enable the MySQL compatibility with:
$ db2set DB2_COMPATIBILITY_VECTOR=MYS
$ db2stop
$ db2start
in db2cmd in order to use that syntax.
SELECT * FROM foo LIMIT 10, 1;
try the limit and offset in mysql..
this mostly use in creating pagination