I, I would like to make a query and sorting my members in a special way... Could someone help ?
Here's the problem.
I would like to select members in my table using a special sort order.
The profile fields values are stored in a table wp_bp_xprofile_data like this :
id | field_id | user_id | value
--------+----------+---------+----------
For example, I have 3 fields
NICKNAME (field_id = 1)
FIRSTNAME (field_id = 2)
LASTNAME (field_id = 3)
The table rows will look like this :
id | field_id | user_id | value
--------+----------+---------+----------
2544 1 100 fib
2545 2 100 john
2546 3 100 arenzich
2547 1 200 dog
2548 2 200 rick
2549 3 200 zarenburg
2550 1 300 fox
2551 2 300 frank
2552 3 300 arenzich
I've got this query to sort them using one field, for example to sort them by nickname alphabetically :
SELECT *
FROM wp_bp_xprofile_data u WHERE u.field_id = 1 ORDER BY u.value ASC
So they will be sorted like this : dog(200),fib(100), then fox(300).
Now, I would like to sort them not one but several fields (firstname and lastname; to differenciate people with same lastname) so that the query returns the users in this order :
frank arenzich (300), john arenzich (100), frank arenzich (200).
Any idea for doing this ?
Thanks A LOT !!!
This will probably need to be done by first pivoting this into a proper table by column, and then ordering that on multiple columns.
Note: this will not produce output in the same format as your original table, but is arguably a lot more flexible and useful as it combines all information about each user_id into a single row.
/* A column-wise pivot of NICKNAME, FIRSTNAME, LASTNAME */
SELECT
user_id,
MAX(CASE WHEN field_id = 1 THEN value ELSE null END) AS NICKNAME,
MAX(CASE WHEN field_id = 2 THEN value ELSE null END) AS FIRSTNAME,
MAX(CASE WHEN field_id = 3 THEN value ELSE null END) AS LASTNAME
FROM wp_bp_xprofile_data
GROUP BY user_id
/* Include the HAVING if you only want those who have both first & last names specified */
HAVING
FIRSTNAME IS NOT NULL
AND LASTNAME IS NOT NULL
/* Pivoted columns can then be treated in the ORDER BY */
ORDER BY
FIRSTNAME,
LASTNAME
Here is a demonstration...
It looks like this is a Wordpress table, so you may not be in a position to change its structure. But if you do have the option of modifying it, I would recommend changing the structure to resemble the pivot's output to begin with.
Related
After some research I haven't found what I need and I thought I'll ask here. I'm currently trying to develop a advanced search mode for a application and I'm stuck with my task. Maybe you can help me. So imagine I have the following table:
ID | Name | Surname
1 | John | Mim
2 | Johnny | Crazy
3 | Mike | Something
4 | Milk | Milk
5 | Peter | IDontknow
6 | Mitch | SomeName
Then in my frontend, there's one input field. The input of that field will go trough the query in that way:
SELECT name, surname FROM people WHERE name LIKE 'input%' OR surname LIKE 'input%'
Now lets say my input is "Mi", so I'll have 3 columns match in the "name" column, and 2 in the surname. And that's what I'm looking for.
A count which ouputs the following:
Column | Count
Name | 3
Surname | 2
Is there a way to achieve this in only one query?
What I've tried so far:
I actually created the table above on my localhost in my database and tried different queries. Tried with SELECT count(name), count(surname), but that would output 3 for both counts. So I'm not even sure if that's possible in only one query.
use union all
SELECT 'name' as col, count(name) as cnt FROM people WHERE name LIKE 'input%'
union all
SELECT 'surname', count(surname) FROM people WHERE surname LIKE 'input%'
make customize group using case when
SELECT (case when name LIKE 'input%' then 'name'
else 'surname' end) as Column, count(*) as cnt
FROM people WHERE name LIKE 'input%' OR surname LIKE 'input%'
group by Column
Try this:
SELECT "Name" as Column, count(*) as Count FROM people WHERE name LIKE 'mi%'
UNION
SELECT "Surname" as Column, count(*) as Count FROM people WHERE surname LIKE 'mi%'
In Mysql booleans are evaluated as 1 or 0, so you can do this:
select 'Name' Column, sum(name LIKE 'input%') Count from people
union all
select 'Surname', sum(surname LIKE 'input%') from people
For Mysql 8.0+ you can avoid the double scan of the table with a CTE:
with cte as (
select
sum(name LIKE 'input%') namecounter,
sum(surname LIKE 'input%') surnamecounter
from people
)
select 'Name' Column, namecounter Count from cte
union all
select 'Surname', surnamecounter from cte
The solution without UNION[ ALL] of the people table:
SELECT
CASE cj.x WHEN 1 THEN 'Name' ELSE 'Surname' END AS `Column`,
CASE cj.x
WHEN 1 THEN COUNT(CASE WHEN Name LIKE concat(#input, '%') THEN 1 end)
ELSE COUNT(CASE WHEN Surname LIKE concat(#input, '%') THEN 1 END)
END `Count`
FROM people CROSS JOIN (SELECT 1 AS x UNION ALL SELECT 2) AS cj
WHERE Name LIKE concat(#input, '%') OR Surname LIKE concat(#input, '%')
GROUP BY cj.x;
Output for the Mi input:
| Column | Count |
+---------+-------+
| Name | 3 |
| Surname | 2 |
Test it online with SQL Fiddle.
I have a table like this:
userid | trackid | path
123 70000 ad
123 NULL abc.com
123 NULL Apply
345 70001 Apply
345 70001 Apply
345 NULL Direct
345 NULL abc.com
345 NULL cdf.com
And I want a query like this. When path='abc.com', num_website +1; when path='Apply', num_apply +1
userid | num_website | num_Apply | num_website/num_Apply
123 1 1 1
345 1 2 0.5
My syntax looks like this:
select * from
(select userid,count(path) as is_CWS
from TABLE
where path='abc.com'
group by userid
having count(path)>1) a1
JOIN
(select userid,count(userid) as Apply_num from
where trackid is not NULL
group by userid) a2
on a1.userid=a2.userid
My question is
1. how to have the field num_website/num_apply in term of my syntax above?
2. is there any other easier way to get the result I want?
Any spots shared will appreciate.
The simplest way to do it would be to change the select line:
SELECT a1.userid, a1.is_CWS, a2.Apply_num, a1.is_CWS/a2.Apply_num FROM
(select userid,count(path) as is_CWS
from TABLE
where path='abc.com'
group by userid
having count(path)>1) a1
JOIN
(select userid,count(userid) as Apply_num
from TABLE
where trackid is not NULL
group by userid) a2
on a1.userid=a2.userid
and then continue with the rest of your query as you have it. The star means "select everything." If you wanted to select only a few things, you would just list those things in place of the star, and if you wanted to select some other values based on those things, you would put those in the stars as well. In this case a1.is_CWS/a2.Apply_num is an expression, and MySql knows how to evaluate it based on the values of a1.is_CWS and a2.Apply_num.
In the same vein, you can do a lot of what those subqueries are doing in a single expression instead of a subquery. objectNotFound has the right idea. Instead of doing a subquery to retrieve the number of rows with a certain attribute, you can select SUM(path="abc.com") as Apply_num and you don't have to join anymore. Making that change gives us:
SELECT a1.userid,
SUM(path="abc.com") as is_CWS,
a2.Apply_num,
is_CWS/a2.Apply_num FROM
TABLE
JOIN
(select userid,count(userid) as Apply_num
FROM TABLE
where trackid is not NULL
group by userid) a2
on a1.userid=a2.userid
GROUP BY userid
Notice I moved the GROUP BY to the end of the query. Also notice instead of referencing a1.is_CWS I now reference just is_CWS (it's no longer inside the a1 subtable so we can just reference it)
You can do the same thing to the other subquery then they can share the GROUP BY clause and you won't need the join anymore.
to get you started ... you can build on top of this :
select
userid,
SUM(CASE WHEN path='abc.com'then 1 else 0 end ) as num_website,
SUM(CASE WHEN path='Apply' and trackid is not NULL then 1 else 0 end ) as Apply_Num
from TABLE
WHERE path='abc.com' or path='Apply' -- may not need this ... play with it
group by userid
I have a table with user info:
user_id | meta_key | meta_value
-----------+----------+-------------
1 | name | John
1 | surname | Doe
2 | name | Luke
3 | name | Jane
I want to select rows with a certain key, given a list of IDs.
If I do:
SELECT meta_value FROM table WHERE meta_key = 'surname' AND user_id IN(1,2,3)
MySQL will only return the info for user 1, since the others do not have surname.
I would like to build a query to return exactly the number of rows as the IDs passed, with NULL (or an empty string) if that particular user has no surname in the table.
I have tried to use IFNULL(meta_value, "") and also using IF, but it does not seem to help.
Any suggestions? I am sure it's a trivial thing but I can't seem to get around this issue.
Here's a SQLfiddle showing the issue: http://sqlfiddle.com/#!9/86eef2/6
My expected output would be:
Doe
NULL
NULL
Try this query:
SELECT DISTINCT user_id,
(SELECT meta_value FROM mytable B WHERE B.user_id = mytable.user_id AND META_KEY = 'surname') AS 'surname_meta_value'
FROM mytable
WHERE user_id IN(1,2,3)
For study purpose, this could be a faster option, in most cases, based on rlb.usa solution:
SELECT user_id,
GROUP_CONCAT(
(CASE WHEN meta_key = "surname"
THEN meta_value
ELSE ''
END) SEPARATOR '')
AS 'surname_meta_value'
FROM mytable WHERE user_id IN(1,2,3)
GROUP BY user_id
I have a table where there are columns students and grade obtained(A-F). A student can appear for test more than once. Sometimes students register but do not appear for test so the grade is not entered but student record entry is made.
I want to get best grade of each student. When I do min(grade) if there is any record with null, null gets selected instead of 'A-F' which indicate proper results. I want to get min of grade if grade exists or null if there are no grades.
SELECT `name`,min(grade) FROM `scores` group by `name`
Id | Name | Grade
1 | 1 | B
2 | 1 |
3 | 1 | A
4 | 2 | C
5 | 2 | D
For name 1 it is fetching second record not the third one having 'A'.
As per the conversations in the comments, the easiest solution may be to convert your empty strings to null, and let the builtin min function do the heavy lifting:
ALTER TABLE scores MODIFY grade VARCHAR(1) NULL;
UPDATE scores
SET grade = null
WHERE grade = '';
SELECT name, MIN(grade)
FROM scores
GROUP BY name
If this is not possible, a dirty trick you could use is to have a case expression convert the empty string to a something you know will come after F:
SELECT name,
MIN(CASE grade WHEN '' THEN 'DID NOT PARTICIPATE' ELSE grade END)
FROM scores
GROUP BY name
And if you really need the empty string back, you can have another case expression around the min:
SELECT name, CASE best_grade WHEN 'HHH' THEN '' ELSE best_grade END
FROM (SELECT name,
MIN(CASE grade WHEN '' THEN 'HHH' ELSE grade END) AS
best_grade
FROM scores
GROUP BY name) t
Change your query slightly to -
SELECT `name`,min(grade) FROM `scores` WHERE grade <> "" group by `name`
If the name has a grade/s assigned to it then the lowest will be returned else the resultset will be null
I'm having trouble with summing the fields values based on another fields value.
I need to SUM(activities.points) based on activities.activity_type if it's used_points or added_points and put it in AS used_points/added_points.
Table activities:
id | subscription_id | activity_type | points
--------------------------------------------------
1 | 1 | used_points | 10
2 | 1 | used_points | 50
3 | 1 | added_points | 20
4 | 1 | added_points | 30
5 | 2 | used_points | 20
6 | 2 | used_points | 45
7 | 2 | added_points | 45
8 | 2 | added_points | 45
Table subscriptions:
id | name | current_points
-------------------------------------
1 | card_1 | 700
2 | card_2 | 900
What I need:
name | current_points | used_points | added_points
-----------------------------------------------------------
card_1 | 700 | 60 | 50
card_2 | 900 | 65 | 90
What I tried :
SELECT
subscriptions.name,
subscriptions.current_points,
IF(activities.activity_type="used_points", SUM(activities.points), null)
AS used_points,
IF(activities.activity_type="added_points", SUM(activities.points), null)
AS added_points
FROM activities
JOIN subscriptions
ON activities.subscription.id = subscription.id
GROUP BY subscriptions.name
Which is wrong.
Thanks
You want to use SUM(IF( )). You want to add up the values returned from the IF. You want that IF expression to be evaluated for each individual row. Then, use the SUM aggregate to add up the value returned for each row.
Remove the SUM aggregate from inside the IF expression and instead, wrap the IF inside a SUM.
Followup
Q But why SUM() inside of IF doesn't work ?
A Well, it does work. It's just not working the way you want it to work.
The MySQL SUM function is an "aggregate" function. It aggregates rows together, and returns a single value.
For an expression of this form: IF(col='foo',SUM(numcol),0)
What MySQL is doing is aggregating all the rows into the SUM, and returning a single value.
Other databases would pitch a fit, and throw an error with the reference to the non-aggregate col in that expression. MySQL is more lenient, and treats the col reference like it was an aggregate (like MIN(col), or MAX(col)... working on a group of rows, and returning a single value. In this case, MySQL is selecting a single, sample row. (It's not determinate which row will be "chosen" as the sample row.) So that reference to col is sort of like a GET_VALUE_FROM_SAMPLE_ROW(col). Once the aggregates are completed, then that IF expression gets evaluated once.
If you start with this query, this is the set of rows you want to operate on.
SELECT s.name
, s.current_points
, a.activity_type
, a.points
, IF(a.activity_type='used_points',a.points,NULL) AS used_points
, IF(a.activity_type='added_points',a.points,NULL) AS added_points
FROM subscriptions s
JOIN activities a
ON a.subscription_id = s.id
When you add a GROUP BY clause, that's going to aggregate some of those rows together. What you will get back for the non-aggregates is values from a sample row.
Try adding GROUP BY s.name to the query, and see what is returned.
Also try adding in some aggregates, such as SUM(a.points)
SELECT s.name
, s.current_points
, a.activity_type
, a.points
, IF(a.activity_type='used_points',a.points,NULL) AS used_points
, IF(a.activity_type='added_points',a.points,NULL) AS added_points
, SUM(a.points) AS total_points
FROM subscriptions s
JOIN activities a
ON a.subscription_id = s.id
GROUP BY s.name
Finally, we can add in the expressions in your query into the SELECT list:
, IF(a.activty_type='used_points',SUM(a.points),NULL) AS if_used_sum
, IF(a.activty_type='added_points',SUM(a.points),NULL) AS if_added_sum
What we discover is that the value returned from these expressions will either be SUM(a.points), which will match the total_points, or it will be NULL. And we can see the value of the activity_type column, retrieved from a single, sample row for each group, and we can see that this is expression is "working", it's just not doing what we you really want to happen: for the conditional test to run on each individual row, returning a value for points or a null, and then summing that up for the group.
Your code is only slightly out:
SELECT
subscriptions.name,
subscriptions.current_points,
SUM(IF(activities.activity_type="used_points", 0, activities.points))
AS used_points,
SUM(IF(activities.activity_type="added_points", 0, activities.points))
AS added_points
FROM activities
JOIN subscriptions
ON activities.subscription_id = subscription.id
GROUP BY subscriptions.name, subscriptions.current_points
Note the fixed typo in the second last line - you wrote subscription.id instead of subscription_id. Also you only grouped by name instead of name and current_points, not sure if that's allowed in mysql (I use T-SQL), it's good practice to have it there anyway.
Well, I did it not using the IF statement. Here's the example (http://sqlfiddle.com/#!2/076c3f/12):
SELECT
subs.name,
subs.current_points,
(SELECT SUM(points) FROM activities WHERE type = 1 AND subs_id = subs.id) AS used_points,
(SELECT SUM(points) FROM activities WHERE type = 2 AND subs_id = subs.id) AS added_points
FROM activities
JOIN subs ON activities.id = subs.id
GROUP BY subs.name
NOTE: I changed the type from VARCHAR to INT to simplify.
Try change
IF(activities.activity_type="used_points", null, SUM(activities.points))
AS used_points,
IF(activities.activity_type="added_points", null, SUM(activities.points))
AS added_points
To next
SUM(IF(activities.activity_type="used_points", activities.points, 0))
AS used_points,
SUM(IF(activities.activity_type="added_points", activities.points, 0))
AS added_points
In this way you check column and sum points or 0
To sum a column of integer values(c1) based on another column of character values(c2). And if you need to sum only not null values, the below code will help.
SELECT SUM(c1) FROM table_name WHERE c2 <> '' AND c2 IS NOT NULL