I have a query like below, it is working fine but not optimized, since it takes 1.5 sec to run. How to make this to an optimized result?
select h.keyword_id,
( select count(DISTINCT(user_id)) from history where category_id = 6
and h.keyword_id=keyword_id group by keyword_id ) as cat_6,
( select count(DISTINCT(user_id)) from history where category_id = 7
and h.keyword_id = keyword_id group by keyword_id ) as cat_7
from
history h group by h.keyword_id
History table
his_id keyword_id category_id user_id
1 1 6 12
2 1 6 12
3 1 7 12
4 1 7 12
5 2 6 13
6 2 6 13
7 2 7 13
8 3 6 13
Result:
keyword_id cat_6 cat_7
1 2 2 (unique users)
2 2 1
3 1 0
You can rewrite your query like this:
select h.keyword_id,
count(distinct if(category_id = 6, user_id, null)) as cat_6,
count(distinct if(category_id = 7, user_id, null)) as cat_7
from
history h
group by h.keyword_id
Your desired result based on the sample data is by the way false. In each keyword_id there's always just one distinct user_id.
you can see the query in action in an sqlfiddle here
For more optimization, you'd have to post the result of show create table history and the output of explain <your_query>;
Need MySQL query for below problem
Consider a table having student and their marks in a particular subject
Schema
std_id int(11)
marks int(11)
Sample data
std_id marks
1 10
2 15
3 90
4 120
5 25
6 29
7 121
8 122
Now I have an web app in which a form will take a input (int) from user.
For eg 12
then I am required to show total number of student ids (std_id) and their corresponding marks group.
Eg
std_total (tot no of students) group (marks range we got from form)
1 0-11
1 12-23
2 24-35
1 84-95
3 120-131
#Barmar Your answer was almost correct, I made few changes to clean the output. Your query gives output as below :
0-11 2
1-12 2
2-13 1
3-14 1
4-15 1
6-17 1
7-18 2
My query return Outout as
0-11 2
12-23 2
24-35 1
36-47 1
48-59 1
72-83 1
84-95 2
SELECT CONCAT(FLOOR(marks/12)*12, '-', FLOOR(marks/12)+11*(FLOOR(marks/12))+11) AS `group`, COUNT(*) as `std_total`
FROM yourTable
GROUP BY `group`
Use division and FLOOR() to get the beginning of each range.
SELECT CONCAT(FLOOR(marks/12), '-', FLOOR(marks/12)+11) AS `group`, COUNT(*) as `std_total`
FROM yourTable
GROUP BY `group`
I have my data base like this
id project_id client_id price
1 1 1 200
2 2 1 123
3 2 1 100
4 1 1 87
5 1 1 143
6 1 1 100
7 3 3 123
8 3 3 99
9 4 3 86
10 4 3 43
11 4 3 145
12 4 3 155
Now here I want that it will sum the price columns with the same client_id.
For that I just made my query like this
Select `project_id`, SUM(`price`) FROM `table-name` GROUP BY `client_id`
This one is doing sum the price but I am getting only two project_id in the result. I want the result should be all the distinct project for the client id and the price will be summed for the group clients.
So can someone tell me how to do this? Any help and suggestions will be really appreciable. Thanks
You should not have "bare" column in a group by query that are not in the group by statement.
If you want the list of projects, you can get them in a list like this:
SELECT client_id, GROUP_CONCAT(project_id), SUM(price)
FROM table-name
GROUP BY client_id;
you only have two client that why you are getting only two record , you can group by two column,
Select `project_id`, SUM(`price`) FROM `table-name` GROUP BY `client_id`, `project_id`
I have two days trying to do this query with no luck.
I have two tables 'DEMAND' and 'DEMAND_STATE' (one to many relation). The table DEMAND_STATE have millions entries.
CREATE TABLE DEMAND
(
ID INT NOT NULL,
DESTINY_ID INT NOT NULL
)
CREATE TABLE DEMAND_STATE
(
ID INT NOT NULL,
PRIORITY INT NOT NULL,
QUANTITY DOUBLE NOT NULL,
CASE_ID INT NOT NULL,
DEMAND_ID INT NOT NULL,
PHASE_ID INT NOT NULL
)
The QUANTITY of the DEMAND_STATE is given according to a CASE_ID and PHASE_ID. We have 'N' PHASES in 'M' CASES. Always the same number of Phases in all Cases. We always have a initial Base Quantity called 'BASE CASE' in the Case with CASE_ID = 1.
For example to obtain quantity for Case (id=2) and Case Base (id=1)
select D.*, S.PRIORITY, S.QUANTITY, S.CASE_ID, S.DEMAND_ID, S.PHASE_ID
FROM DEMAND D
join DEMAND_STATE S on (D.ID = S.DEMAND_ID)
WHERE (S.CASE_ID = 2 OR S.CASE_ID = 1)
(paste only for id=8)
ID PRIORITY QUANTITY CASE_ID DEMAND_ID PHASE_ID
8 0 85 1 8 1
8 0 83 1 8 2
8 0 88 1 8 3
8 0 89 1 8 4
8 10 85 2 8 1
8 10 84 2 8 2
8 10 86 2 8 3
8 10 89 2 8 4
We need to obtain for all Demand in 'DEMAND' only the Quantity for Each Phase with MAX priority. The idea is no duplicate DEMAND_STATE data for each new Case creation. Only create new state rows when Demand-Case-Phase is different to Case Base. This is a new project and we accept changes in model for better performance.
I also tried with the MAX calculation. This query over DEMAND_STATE works fine but only obtain data for a concrete DEMAND_ID. Further i think this solution can be so expensive.
SELECT P.ID, P.QUANTITY, P.CASE_ID, P.DEMAND_ID, P.PHASE_ID
FROM DEMAND_STATE P
JOIN (
SELECT PHASE_ID, MAX(PRIORITY) max_priority, S.DEMAND_ID
from DEMAND_STATE S
WHERE S.DEMAND_ID = 1
AND (S.CASE_ID=1 OR S.CASE_ID=2)
GROUP BY S.PHASE_ID
) SUB
ON (SUB.PHASE_ID = P.PHASE_ID AND SUB.max_priority = P.PRIORITY)
WHERE P.DEMAND_ID = 1
GROUP BY P.PHASE_ID
The result:
ID QUANTITY CASE_ID DEMAND_ID PHASE_ID
1 86 1 1 1
2 85 1 1 2
3 81 1 1 3
8 500 2 1 4
This is the result expected:
ID ID PRIORITY QUANTITY CASE_ID PHASE_ID
8 1 0 86 1 1 (data from Case Base id=1 priority 0)
8 2 10 85 1 2 (data from Case Baseid=1 priority 0)
8 3 10 81 1 3 (data from Case Base id=1 priority 0)
8 64 10 500 2 4 (data from Case id=2 priority 10)
thank for help :)
Edit:
Result of Simon proposal:
ID QUANTITY CASE_ID DEMAND_ID PHASE_ID
1 86 1 1 1
2 85 1 1 2
3 81 1 1 3
4 84 1 1 4 (this row shouldnt exist)
8 500 2 1 4 (this is the correct row)
Also would have to join it with DEMAND
#didierc response:
ID ID MAX(S.PRIORITY) QUANTITY CASE_ID PHASE_ID
1 8 10 500 2 4
2 13 10 81 2 1
2 14 10 83 2 2
2 15 10 84 2 3
3 21 10 81 2 1
4 31 10 86 2 3
4 32 10 80 2 4
4 29 10 85 2 1
4 30 10 81 2 2
we need for each DEMAND four rows with the quantity Value. In Case Base we have four quantity and in Case 2 we only change the quantity for phase 4. We need always four rows for each demand.
Database DEMAND_STATE data:
ID PRIORITY QUANTITY CASE_ID DEMAND_ID PHASE_ID
1 0 86 1 1 1
2 0 85 1 1 2
3 0 81 1 1 3
4 0 84 1 1 4
8 10 500 2 1 4
We need to obtain for all Demand in 'DEMAND' only the Quantity for Each Phase with MAX priority
I translate the above, according to your sample result set, as:
SELECT
D.ID, S.ID, MAX(S.PRIORITY), S.QUANTITY, S.CASE_ID, S.PHASE_ID
FROM DEMAND D
LEFT JOIN DEMAND_STATE S
ON D.ID = S.DEMAND_ID
GROUP BY S.PHASE_ID, S.DEMAND_ID
Update:
To get the maximum priority for each pair(demand_id,phase_id)n we use the following query:
SELECT
DEMAND_ID, PHASE_ID, MAX(PRIORITY) AS PRIORITY
FROM DEMAND_STATE
GROUP BY DEMAND_ID, PHASE_ID
Next, to retrieve the set of phases for a given demand, just make an inner join on demand state:
SELECT S.* FROM DEMAND_STATE S
INNER JOIN (
SELECT
DEMAND_ID, PHASE_ID, MAX(PRIORITY) AS PRIORITY
FROM DEMAND_STATE
GROUP BY DEMAND_ID, PHASE_ID
) S2
USING (DEMAND_ID,PHASE_ID, PRIORITY)
WHERE DEMAND_ID = 1
If you want to limit the possible cases, include a where clause in the query S2:
SELECT S.* FROM DEMAND_STATE S
INNER JOIN (
SELECT
DEMAND_ID, PHASE_ID, MAX(PRIORITY) AS PRIORITY
FROM DEMAND_STATE
WHERE CASE_ID IN (1,2)
GROUP BY DEMAND_ID, PHASE_ID
) S2
USING (DEMAND_ID,PHASE_ID, PRIORITY)
WHERE DEMAND_ID = 1
However, your comments and update indicates that MAX(PRIORITY) does not seem very relevant after all. My understanding is that you have a base case, which may be overriden by another case in a given scenario (that scenario is the pair base case + some other case). Clarify that point in your question body if this is incorrect. If that is the case, you may change the above query by replacing PRIORITY by CASE_ID:
SELECT S.* FROM DEMAND_STATE S
INNER JOIN (
SELECT
DEMAND_ID, PHASE_ID, MAX(CASE_ID) AS CASE_ID
FROM DEMAND_STATE
WHERE CASE_ID IN (1,2)
GROUP BY DEMAND_ID, PHASE_ID
) S2
USING (DEMAND_ID,PHASE_ID, CASE_ID)
WHERE DEMAND_ID = 1
The only reason I see from having a priority is if you wish to combine more than 2 cases, and use priority to select which case will prevail depending on the phase.
You may of course prepend an inner join on DEMAND to include the related demand data.
Use of subqueries should be able to do as you wish, if I understand your question correctly. Something along the lines of the following:
SELECT
P.ID,
P.QUANTITY,
P.CASE_ID,
P.DEMAND_ID,
P.PHASE_ID
FROM DEMAND_STATE P
INNER JOIN (
-- Next level up groups it down and so gets the rows first returned for each PHASE_ID, which is the highest priority due to the subquery
SELECT
D.PHASE_ID,
D.PRIORITY,
D.DEMAND_ID
FROM (
-- Top level query to get all rows and order them in desc priority order
SELECT
S.PHASE_ID,
S.PRIORITY,
S.DEMAND_ID
FROM DEMAND_STATE S
WHERE S.DEMAND_ID IN (1) -- Update this to be whichever DEMAND_IDs you are interested in
AND S.CASE_ID IN (1,2)
ORDER BY
S.PHASE_ID ASC,
S.DEMAND_ID ASC,
S.PRIORITY DESC
) D
GROUP BY
D.PHASE_ID,
S.DEMAND_ID
) SUB
ON SUB.PHASE_ID = P.PHASE_ID
AND SUB.DEMAND_ID = P.DEMAND_ID
The top level subquery exists to get the rows you are interested in and order them in an order which allows predictable results when they are then grouped down by PHASE_ID and DEMAND_ID. This in turn allows a simple INNER JOIN to DEMAND_STATE hopefully (unless I have misunderstood your query)
This may still be expensive though depending on how much data is within that top level query.
I have a table with 3 columns and looks like
branchid semesterid courseid
4 25 2
4 36 5
4 23 3
4 12 10
4 34 15
4 2 7
4 23 42
7 23 9
7 10 6
7 34 3
7 20 17
I need the count of semesterid and courseid of that branch
SELECT branchid, count(semesterid), count(courseid) WHERE branchid = 4
When I execute this query, the count(semesterid) shows wrong count and courseid shows correct count of 7
With my crystal ball I predict you need this instead:
SELECT COUNT(DISTINCT semesterid),
COUNT(DISTINCT courseid)
FROM Table1
WHERE branchid = 4;
... as the query shown should work just fine for counting the number of records (but not unique records).
try:
SELECT branchid,
count(distinct semesterid) as semesterid,
count(distinct courseid) as courseid
FROM <table>
WHERE branchid = 4
group by branchid
If you want the number of unique results you have to replace count(id) with count(distinct id)