I am a beginner regarding SQL queries so I hope that someone can help me with this.
I have a table that has 2 columns that are called MID and jachtID.
What I need is the count of how many of the same jachtIDS there are with different MIDS attached to them like this:
MID jachtID
89 10
95 10
83 11
The result should look something like this:
MID jachtID count
89 10 2
95 10 2
83 11 1
And I need this for all of the rows
I have tried using
SELECT count(DISTINCT jachtID) FROM table
But this just gives me 1 big number and not the result that I need.
Any help would be appreciated.
You can try the following query:
SELECT
T.MID,
T.jachtID,
jT.total
FROM table T INNER JOIN
(
SELECT
jachtID,
COUNT(*) total
FROM table
GROUP BY jachtID
)AS jT
ON T.jachtID = jT.jachtID
First get count of each jachtID by the following query:
SELECT
jachtID,
COUNT(*) total
FROM table
GROUP BY jachtID
Then make an INNER JOIN between the main table and the above query and get the corresponding jatchtID count thereby.
You might be able to do this with some GROUP BY magic, but I'm not sure, since you want all the rows. Using a sub query will work, though.
SELECT
a.MID,
a.jachtID,
(SELECT count(b.jachtID) FROM table AS b WHERE b.jachtID= a.jachtID) AS `count`
FROM table AS a
Related
I have a table named items which has 3 columns : id, user_id, item_name.
I want to select and show all users that have most submitted items in that table.
For instance :
User-1 has 3 items,
User-2 has 8 items,
User-3 has 5 items,
User-4 has 8 items, and
User-5 has 8 items too.
Based on what I need, the query should be outputting User-2, User-4 and User-5.
My knowledge of MySQL is not thorough unfortunately and I can't get this done by myself.
Your help is much appreciated.
EDIT #1 :
Here's the query that I tried and didn't output my desired result :
SELECT COUNT(id) AS total_count
, user_id
FROM ".DB_PREFIX."items
GROUP
BY user_id
It shows all users and their total number of items submitted. As I mentioned earlier, I need all top users.
E.g.:
SELECT a.*
FROM
( SELECT user_id
, COUNT(*) total
FROM my_table
GROUP
BY user_id
) a
JOIN
( SELECT COUNT(*) total
FROM my_table
GROUP
BY user_id
ORDER
BY total DESC
LIMIT 1
) b
ON b.total = a.total;
I have a SQL statement to select data:
SELECT DISTINCT count(table.data) as cntd, table.datatwo
FROM table LEFT JOIN tabletwo ON table.id=tabletwo.tableid
WHERE tabletwo.dated='2016-11-17' AND table.datafive='1'
If I keep it the way above - it returns the data as below:
cntd datatwo
4 92
However the correct data should be:
cntd datatwo
2 92
2 93
As there are two different datatwo. When I select the statement without cont - it shows both datatwo.
datatwo
92
93
Where am I making a mistake?
Despite how random and unintuitive your table naming is, it appears what you want is to use a GROUP BY statement:
SELECT
DISTINCT count(table.data) as cntd,
table.datatwo
FROM table
LEFT JOIN tabletwo ON table.id=tabletwo.tableid
WHERE tabletwo.dated='2016-11-17'
AND table.datafive='1'
GROUP BY tabletwo.tableid
The COUNT statement is an aggregate function so it causes the rows to collapse down to one. Grouping by the unique value for each row will cause it to aggregate in groups.
I have multiple tables on specific database and each table similar to each other.
Table:
id series folder
1 Naruto 670
2 Naruto 671
3 Naruto 672
Each table has exact setup. Just series name changes. I want to pick up only 1 entry from series row and highest number from the folder row.
I will use this data to make it php array and use it for JSON data.
Here is my code:
'SELECT naruto.MAX(klasor), naruto.seri, one_piece.MAX(klasor), one_piece.seri, bleach.MAX(klasor), bleach.seri FROM `naruto` INNER JOIN `one_piece` INNER JOIN `bleach ON` LIMIT 1'
Use a GROUP BY clause like
select id,series,max(folder) as max_folder
from table1
group by series
Im having a brain fart as to how I would do this.
I need to select only the latest entry in a group of same id entries
I have records in an appointment table.
lead_id app_id
4 42
3 43
1 44
2 45
2 46 (want this one)
1 48
3 49 (this one)
4 50 (this one)
1 51 (this one)
The results I require are app_id 46,49,50,51
Only the latest entries in the appointment table, based on duplicate lead_id identifiers.
Here is the query you're looking for:
SELECT A.lead_id
,MAX(A.app_id) AS [last_app_id]
FROM appointment A
GROUP BY A.lead_id
If you want to have every columns corresponding to these expected rows:
SELECT A.*
FROM appointment A
INNER JOIN (SELECT A2.lead_id
,MAX(A2.app_id) AS [last_app_id]
FROM appointment A2
GROUP BY A2.lead_id) M ON M.lead_id = A.lead_id
AND M.last_app_id = A.app_id
ORDER BY A.lead_id
Here i simply use the previous query for a jointure in order to get only the desired rows.
Hope this will help you.
The accepted answer by George Garchagudashvili is not a good answer, because it has group by with unaggregated columns in the select. Select * with group by is simply something that should not be allowed in SQL -- and it isn't in almost all databases. Happily, the default version of the more recent versions of MySQL also rejects this syntax.
An efficient solution is:
select a.*
from appointment a
where a.app_id = (select max(a2.app_id)
from appointment a2
where a2.lead_id = a.lead_id
);
With an index on appointment(lead_id, app_id), this should be as fast or faster than George's query.
I think this is much more optimal and efficient way of doing it (sorting next grouping):
SELECT * FROM (
SELECT * FROM appointment
ORDER BY lead_id, app_id DESC
) AS ord
GROUP BY lead_id
this will be useful when you need all other fields too from the table without complicated queries
Result:
lead_id app_id
1 51
2 46
3 49
4 50
I have the following results for my database table:
The Query:
SELECT
service_titles.user_id, service_titles.slide_id, service_titles.name as title_name ,service_names.name as service_name
FROM service_names
INNER JOIN service_titles ON service_names.title_id = service_titles.id
So what needs to happen is:
If the user has 2 unique service titles, then the max number of service_names for that title will be 6
If the user has 1 service title, the the max number of service_names for that title will be 16
I will be using PHP for all of the coding, but I am wondering how I would go about this. I need a way to count how many unique service_titles there are for that user and slide, and then count how many service items there are for each title.
Thanks for any help!
SELECT COUNT(DISTINCT service_titles.name)
FROM service_names
INNER JOIN service_titles ON service_names.title_id = service_titles.id
GROUP BY service_titles.user_id, service_titles.slide_id
That'll get you the number of distinct title_names for each user_id/slide_id combo.
SELECT COUNT(DISTINCT service_names.name)
FROM service_names
INNER JOIN service_titles ON service_names.title_id = service_titles.id
GROUP BY service_titles.user_id, service_titles.slide_id
... and that's the number of distinct service_names for same. If you want both in one query, you can put both COUNTs together, since you're using the same GROUP BY regardless.
You could use a CASE statement within your query to change the max number of service_names.
See MySQL CASE statement reference
To do this in the SQL itself would be quicker than evaluating it in PHP.
To count how many distinct titles you can try:
SELECT user_id, COUNT(DISTINCT name)
FROM service_titles
GROUP BY user_id