How do I select count() and LIMIT? - mysql

SELECT * FROM ...LIMIT 5, 10
But what if I want the total rows? I don't want to make another query without the limit. I just want this one query to return the total rows if I didn't put the LIMIT in there.

the only way is like this (use 2 queries):
SELECT SQL_CALC_FOUND_ROWS ..... FROM table WHERE ... LIMIT 5, 10;
and right after run this :
SELECT FOUND_ROWS();
read more :
http://www.arraystudio.com/as-workshop/mysql-get-total-number-of-rows-when-using-limit.html
http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_found-rows

Use
select count (*) from table_name

Related

select all the rows from my table except the first 20 rows

I want to select all the rows from my table except the first 20 rows. How it possible? The total number of rows are not static.
SELECT statistics_id,title, user_name FROM (
SELECT statistics_id,title, user_name FROM statistics ORDER BY statistics_id DESC
LIMIT(select count(*)from statistics )-20
) sub
ORDER BY access_statistics_id ASC
I know 'LIMIT(select count(*)from statistics )-20' is not a correct method. Please help.
the documentation says (https://dev.mysql.com/doc/refman/5.5/en/select.html) the following:
To retrieve all rows from a certain offset up to the end of the result set, you can use some large number for the second parameter. This statement retrieves all rows from the 96th row to the last:
SELECT * FROM tbl LIMIT 95,18446744073709551615;
so you could use something like
LIMIT 20, veryLargeNumber
Try this
DECLARE v_max bigint unsigned default ~0;
SELECT statistics_id,title, user_name
FROM statistics
LIMIT 20, v_max;
After writing the select query u just have to include,
LIMIT 21,100;
21-Offset i.e from which row you want to start selecting and
100- is the Limit[Which you can set according to your need]
You actually need:
SELECT
statistics_id, title, user_name
FROM statistics
ORDER BY
statistics_id ASC
LIMIT 20, 18446744073709551615;
As per MySQL Documentation
To retrieve all rows from a certain offset up to the end of the result
set, you can use some large number for the second parameter. This
statement retrieves all rows from the 96th row to the last:
SELECT * FROM tbl LIMIT 95,18446744073709551615;
If your table grows fast, selecting all rows (with exception of first 20) is not a good idea. In such case, you should batch your query, and handle a subset of entries at a time, some thing like:
SELECT * FROM tbl LIMIT 20,120;
Try using the offset option for the LIMIT syntax. you can read more about the LIMIT syntax at http://dev.mysql.com/doc/refman/5.0/en/select.html.
SELECT `statistics_id`
, `title`
, `user_name`
FROM `statistics`
ORDER BY `statistics_id` ASC
LIMIT 20, 18446744073709551615

SQL Query using Random

Hi could anyone help me with something?
I need a mysql query that can return 4 values from a column in some table, also select all fiels from each row.
something like:
SELECT * FROM dadoslivros WHERE RAND() =1 limit 100;
But i only want the random form row ID.
Thanks.
It seems like you just want to use ORDER BY RAND():
select *
from dadoslivros
order by rand()
limit 100
See SQL Fiddle with Demo

Why mysql return one row?

When I use count() function MySQL return one row. I need to use count function for pagination system, I don't have a better idea.
My SQL is:
SELECT *, count(id_question) AS num FROM `questions` LIMIT 0, 10
when you use any aggregate function, without the group by clause you see only one result.
The COUNT() is an aggregate function and so will group all the rows together. If you need the count of all rows just count the number of rows returned in whatever language you're using.
SQL does not allow to aggregate over the whole table and return all rows at the same time.
You have to use two queries, one for the total number of rows (count) and one for the rows themselves.
Have you tried ...
SELECT *, count(*) AS num FROM `questions` LIMIT 0, 10
or simply using mysql_num_rows() to get the count?
Since count is an aggregate function, it will by design only return one row. You would have two use two queries, one for the select and one for the count.
Alternatively you could do a nested select:
SELECT *, (SELECT count(id_question) from 'questions') AS num FROM `questions` LIMIT 0, 10
You can use mysql_num_rows($queryHandle) on your normal results query. An example:
$query = 'SELECT * FROM `questions` LIMIT 0, 10';
$queryHandle = mysql_query($query);
$count = mysql_num_rows($queryHandle);
$firstRow = mysql_fetch_assoc($queryHandle);
Try:
SELECT * FROM `questions` a
INNER JOIN (
SELECT count(`id_question`) as `num`
FROM `questions`
) b
LIMIT 0, 10;
Each row will now have the total row count of the table as a column called num.

how to specify only start index in LIMIT in MySQL select query?

I want to select the records from the table starting from 3rd row. How this can achieved with LIMIT?
From the MySQL Documentation:
To retrieve all rows from a certain offset up to the end of the
result set, you can use some large number for the second parameter.
This statement retrieves all rows from the 96th row to the last:
SELECT * FROM tbl LIMIT 95,18446744073709551615;
Like this:
SELECT * FROM MyTable LIMIT 2, 18446744073709551615;
(The offset is zero-based)
i am giving syntax
SELECT field1, field2,...fieldN table_name1, table_name2...
[WHERE Clause]
[OFFSET M ][LIMIT N]

Omit the first 5 rows?

I want to SELECT all rows except for the first 5 rows in a table.
How do I do that?
Why can't I just type
$query = "SELECT *
FROM ages
OFFSET 5
ORDER BY id ASC";
SELECT * FROM tbl LIMIT 5,18446744073709551615;
from http://dev.mysql.com/doc/refman/5.0/en/select.html
To retrieve all rows from a certain offset up to the end of the result set, you can use some large number for the second parameter. This statement retrieves all rows from the 96th row to the last:
SELECT * FROM tbl LIMIT 95,18446744073709551615;
In Oracle:
select name, price
from items
where rownum > 5
Here's a solution using variables - just add your order by clause and you should be set.
set #n=-1
select * from TABLE where (#n:=#n+1) >= 5;
I just typed:
$query = "SELECT *
FROM ages
LIMIT 100
OFFSET 10";
Why couldn't anybody give me such an easy answer? :)