count total numbers of same item exist in database - php

assume I have a table that contain a column named post_id and it has the result like
1
1
1
2
2
3
1
1
I want to loop through all the records and count how many times they exist. What I could thought of is
by while loop
if(result[] = 1){$1++}, but the problem is the value of record is not fixed, it can be 9999..
I'd tried
while ($something= $item->fetch_array()) {
while($test[] = $something['post_id'] > 0){
//logic here
}
}

select post_id, count(*)
from table
group by post_id

This is something you can do in SQL. I believe it would be the following:
SELECT post_id, COUNT(*) FROM tablename GROUP BY post_id;
This will return, for each post_id in the table, that post_id and the count of rows with that post_id.

Have you try this.
Assume:
Table one
**Table one**
Column1
1
1
1
2
2
3
1
1
You can use this query to count it.
SELECT one.column1, COUNT(two.column1) FROM one as one, one as two;

Related

MySQL: select last (max) value from column and count of all rows

How can I select last (=max) value from column and count of all rows in single query?
ID ITEM_ID VALUE
1 1 100
2 1 101
3 2 201
4 3 333
5 2 222
6 1 111
I want to select last / max value for particular ITEM_ID and count of all rows with this ID.
For ITEM_ID = 1 thus:
VALUE COUNT
111 3
My query is like this:
SELECT (SELECT COUNT(*) FROM table) AS count, (SELECT value FROM table ORDER BY id DESC LIMIT 1) AS value FROM table WHERE item_id = 1 LIMIT 1
It works but looks ... weird. Is there any better (simpler / faster) solution? Thanks
You need to do a GROUP BY on column ITEM_ID while getting the MAX() and COUNT() like
select max(value) as `VALUE`,
count(*) as `COUNT`
from your_table
group by ITEM_ID;

MYSQL Select; I cannot figure out how to exclude rows based on a different column value

Table:
id value
100 1
101 1
102 1
102 0
103 1
I want the selection to return id's 100,101,103; that is, if the same id has two rows, one with value=1 and a second with value=0, I want to exclude it.
Appreciate any help.
Try this:-
Select id From table Group By id Having count(*) = 1
Could use the having MySQL construct:
SELECT id, count(*) AS tehCount FROM table GROUP BY id HAVING tehCount = 1;
Try this:
SELECT * FROM
table
GROUP BY id
HAVING COUNT(*) = 1

Selecting a distinct value and the sum of times it shows up in a column

I have an existing table with millions of entries (growing) that consists of:
userid|name|etc...
1 frank ...
1 frank ...
2 joe ...
5 sam ...
1 franky ...
What I need to do is return a table of:
place|name|total
1 franky 3
2 sam 1
3 joe 1
Where total is the SUM(userid = the distinct userid).
Currently I'm doing a query to SELECT DISTINCT userid from table and then foreach returned value in php, I'm doing another query to return the name and sum(userid = userid).
As you can assume, this is very taxing and takes a long time now with all of the values. Is there any way to speed this up by doing 1 query?
i think you need
SELECT #a:=#a+1 AS `place`, name, COUNT(userid) AS `total`
FROM `your_table`, (SELECT #a:= 0) AS a
GROUP BY userid
SELECT userid, COUNT(*)
FROM some_table
GROUP BY userid

MYSQL returning duplicate rows

I have a Database table in MYSQL, it looks like this:
Project_ID user_ID name
11 1 fred
11 2 rick
11 1 fred
I want to get the names in the table, but when I display it I get the same name twice because the user_ID 1 appears twice in the table. I tried to display it with GROUP BY and SUM, but I don't want to do it this way. How do I get it not to return duplicate rows?
Use DISTINCT
SELECT DISTINCT user_ID
, verschil_ma
FROM project_uren
WHERE project_ID = 11
GROUP BY user_ID
Point 1 is that should the user be assigned to the project twice?
Point 2 - Use the DISTINCT keyword to return only unique records - http://dev.mysql.com/doc/refman/5.0/en/distinct-optimization.html
SELECT DISTINCT user_ID
FROM TABLE
WHERE Project_id = 11
That will return you 1 and 2 (You won't get 1 twice)
Thanks
$results = // query
$results = array_unique($results);

PHP MySQL Joins

Is there a way I could somehow do the following?
Table ONE
id c_id type
-------------------
1 1 7
2 2 7
3 3 5
4 4 7
Table TWO
id title live
-------------------
1 row1 1
2 row2 0
3 row3 0
4 row4 1
The c_id column links the data from table ONE to table TWO. Example: in table ONE, if the c_id is 2, that row in table ONE will be directly linked to table TWO's row with id 2, which has a title of "row2".
I want to select from table ONE, everything with type 7, but only if their associated data in table TWO has live set to 1.
Here's how I thought I'd do it, but this doesn't seem to work:
SELECT * FROM ONE, TWO WHERE ONE.type='7' AND TWO.live='1' ORDER BY ONE.id DESC LIMIT 5
I would expect the above to return only rows 1 and 4 from table ONE, because although table ONE has three rows with type "7", only rows 1 and 2's associated row in table TWO have live set to 1.
You were close... try using an implicit join:
SELECT ONE.* FROM ONE, TWO WHERE ONE.type='7' AND TWO.live='1' AND ONE.c_id = TWO.id ORDER BY ONE.id DESC LIMIT 5
select * from one join two on c_id = two.id where type=7 and live = 1
order by one.id desc limit 5

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