This question already has answers here:
Retrieving only a fixed number of rows in MySQL
(6 answers)
Closed 6 years ago.
Consider a database table with 100 rows and the table is updated ie the number of rows increases on a regular basis.
Suppose that when a visitor visits my website, my table consist Xrows, but I want only rows from (X-25) to (X-50) to be visible.
I need help to code a PHP such that only rows from (X-25) to (X-50) are visible
I am new to PHP ,SQL a help would aid me a lot :)
You can use limit to show particular record.
The SQL query below says "return only 10 records, start on record 15":
"SELECT * FROM Orders LIMIT 15, 10";
1) Consider, you have 100 records 0-99. Ad you want to display 20 records starting from 11th record then query will be
"SELECT * FROM Orders LIMIT 11, 20";
2) If you want to display 1st 20 records then query will be :
"SELECT * FROM Orders LIMIT 20";
3) If you want to display latest 20 records then :
"SELECT * FROM Orders ORDER BY orderid DESC LIMIT 20";
To get last 20 records you have inserted..
if you are using auto increment primary key orderid,you can use the query
"SELECT * FROM Orders ORDER BY orderid DESC LIMIT 20";
In MYSQl
SELECT * FROM table LIMIT 25, 25 -- get 25 records after row 26
If you want row 25-50 in descending order you can do this by :
SELECT * FROM (SELECT * FROM ORDERS LIMIT 25, 25) ORDER BY id DESC
Related
I have 10 Records in my database and I want 5 records from it.
Like 1,2,3,4,5,6,7,8,9,10 and I want records from 3,4,5,6,7,8
Records are dynamic and can change very frequently.
Select *
From file
Where file_status = 1
Order By file_date DESC
limit 5
This Won't work, just because this will fetch only last five records..
select * from file where file_status = 1 order by file_date DESC limit 2,6
will get data as your examp
This question already has answers here:
How does MySQL process ORDER BY and LIMIT in a query?
(8 answers)
Closed 4 years ago.
I have a database name BOOKS and I want to retrieve only a limited no. of books from the database everytime I query it. Say, 140 books only, even if the result of the query is more than 140 records.
To limit data selections from a MySQL database use the LIMIT clause. It is used to specify the number of records to retrieve. It also helps improve performance by not retrieving all the records in the database.
If you wish to select all records from 1 - 140 (inclusive) from a table called "BOOKS". The SQL query would then look like this:
$sql = "SELECT * FROM BOOKS LIMIT 140";
When the SQL query above is run, it will return the first 30 records.
The SQL query below says "return only 100 records, start on record 140 (OFFSET 139)":
$sql = "SELECT * FROM BOOKS LIMIT 100 OFFSET 139";
Alternatively you could use this syntax to get the same result:
$sql = "SELECT * FROM BOOKS LIMIT 139, 100";
I'm doing an info system that has announcements, so I wanted to get the data from announce table, first should be the one with max id of course since it is the latest announcement and here is my code for it:
SELECT image FROM announce where id=(SELECT max(id) FROM announce);
Now I wanted to get the data before the max id and I'm using this code here:
SELECT image FROM announce where id=(SELECT max(id)-1 FROM announce);
But it only works if there are no deleted rows,if there are some deleted rows it doesn't work like max id is 10 and the id's 9,8,7 are deleted. That means the present id's are: 1,2,3,4,5,6,10, how will I be able to get the data in the id 6,5,4,3,2,1?
If you ORDER the query by descending order (DESC), and have an OFFSET of one (OFFSET 1), you would get the second to last row. And offset of two would give the row before that, and so on. This also uses LIMIT 1, so we just get one row. LIMIT 1, 1 is the same as LIMIT 1 OFFSET 1.
SELECT image
FROM announce
ORDER BY id DESC
LIMIT 1, 1
MySQL on SELECT statements
You can just use one query with order by and limit instead of the two queries you use:
select image
from announce
order by id desc
limit 2
In case you want to query them separately, you can change limit 2 to limit 1, 1 for you second query to work as you wish.
This question already has answers here:
TOP and ORDER BY sql error
(3 answers)
Closed 6 years ago.
I would like to display only the latest one of those rows which match to my conditions. It will be a conversation listing page where I would like to display only the latest message from the user or his/her partner, and then display the next conversation's latest message between the user and another partner, and so on...
I have this database:
And this code to fetch data:
$db = new PDO("mysql:host=localhost; dbname=dbname", 'root', '');
$stmt4 = $db->prepare("
SELECT *
FROM messages
WHERE messages.from_id=7
OR messages.to_id=7
ORDER BY msg_id DESC
");
$stmt4->execute();
Is it possible somehow?
You only need add LIMIT 1 to your query.
SELECT *
FROM messages
WHERE messages.from_id=7
OR messages.to_id=7
ORDER BY msg_id DESC
LIMIT 1
You can just do
select *
FROM messages
WHERE messages.from_id=7
OR messages.to_id=7
ORDER BY timesent DESC
LIMIT 1
That should work per your requirements, it will only pull in the top record for what is matching your where clause and it will be ordered by the latest time sent.
i have a table i get cars form databases and i list it in this table:
$row_id=$_GET["id"];
$solK = ($row_id-1) * 9;
$sagK = ($row_id) * 9;
$sorgu2 = mysql_query("SELECT * FROM Car WHERE Car_ID > '$solK' AND Car_ID < '$sagK'");
Every page have 9 cars i use id for sort these cars but when i delete a car (for example Carid=5) in first page have 8 cars but other pages have 9 cars how can i get first N values without CarId from databases can you explain with sql codes.
Add a LIMIT to your query.
For example
SELECT * FROM tbl LIMIT 0, 9
will select the first 9 entries from tbl.
In order to match your query and preserve the ordering I'd state it as
SELECT * FROM Car ORDER BY Car_ID LIMIT 0, 9
for the first nine rows. For the next nine rows, just increment both numbers by 10 and so on.
Rather than code it like you have done, just use LIMIT:
SELECT * FROM Car LIMIT 0,9
then
SELECT * FROM Car LIMIT 9,9
Use "LIMIT offset, row_count" in you statement
Try this SQL statement SELECT * FROM Car LIMIT '$pageN*$nperpage', '$nperpage'
Where $nperpage will be a number of items per page and $pageN will be a page number (note that in this case page numbering starts with 0).
http://dev.mysql.com/doc/refman/5.0/en/select.html
I assume the other answers (using limit and offset) will be suited for your case. But if you (or anyone else) ever need to improve performance, and need to manage fast queries for more than the first few pages, you should implement paging like this:
SELECT f1, f2, ...
FROM tbl
WHERE Car_ID > $id
ORDER BY Car_ID
LIMIT 10