Selecting a count on two separate conditions - mysql

Let's say I have the following data.
id name_id completed
1 10 1
2 10 0
3 15 1
4 10 0
5 20 1
6 15 0
7 20 1
8 15 0
I'm trying to find a count by the name id, which is pretty simple
SELECT name_id, COUNT(*) FROM db
GROUP BY name_id
Now, I have a second component which I want to include in the query.
For name_id 10, I want to count just those values where completed is 1. For the other name_id's, I want to select them regardless of whether they are 0 or 1.
So I should end up with:
name_id count(*)
10 1
15 3
20 2
Name_id 10 only has a count of 1 because it's just the 1 which is completed, while the other counts include both 0 and 1.
Can anyone help with this task.
Thanks!

You can use a CASE expression inside of your aggregate function.
SELECT name_id,
sum(case
when name_id = 10
then case when completed = 1 then 1 else 0 end
else 1 end) Total
FROM db
GROUP BY name_id;
See SQL Fiddle with Demo.

Exclude the rows where name_id = 10 and completed = 0:
SELECT name_id, COUNT(*) FROM db
WHERE NOT (completed = 0 AND name_id = 10)
GROUP BY name_id

SELECT name_id, COUNT(*) FROM db
WHERE name_id != 10 or completed = 1
GROUP BY name_id

Count when name_id is not 10. If it is 10, count when completed = 1:
SELECT
name_id,
COUNT(CASE WHEN name_id <> 10 or completed = 1 THEN 1 END)
FROM db
GROUP BY name_id

Related

How to use count in sql based on a IF condition

From this table
groupId
flag
flagValue
1
0
500
2
0
100
1
1
10
2
1
50
3
0
100
1
1
200
3
1
1000
2
1
50
I need this result
groupId
flag1
flag0
valFlag1
valFlag0
totalFlags
1
2
1
210
500
3
2
2
1
100
100
3
3
1
1
1000
100
2
where
flag1 is number of times flag is 1 for a particular group
flag0 is number of times flag is 0 for a particular group
valFlag1 is sum of flagVal when flag is 1
valFlag0 is sum of flagVal when flag is 0
totalFlags is sum of total flags associated with a group
I am stuck as to how to actually count values based on an IF condition.
Anyhelp is appreciated. Thanks.
I have used a table named group_table with your values
Try using this:
SELECT
g.`groupId`,
SUM(g.`flag`=1 ) AS flag1,
SUM(g.`flag`=0) AS flag0,
SUM(CASE WHEN g.`flag`=1 THEN g.`flagValue` ELSE 0 END) AS valFalg1,
SUM(CASE WHEN g.`flag`=0 THEN g.`flagValue` ELSE 0 END) AS valFalg0,
COUNT(*) AS totalFlags
FROM
`group_table` g
GROUP BY g.`groupId`
If you have to use the IF,
SELECT
g.`groupId`,
IF(g.`flag`=1,1,0 ) AS flag1,
IF(g.`flag`=0,1,0) AS flag0,
SUM(IF(g.`flag`=1,g.`flagValue`,0 )) AS valFalg1,
SUM(IF(g.`flag`=0,g.`flagValue`,0 )) AS valFalg0,
COUNT(*) AS totalFlags
FROM
`group_table` g
GROUP BY g.`groupId`, flag1, flag0
They'll produce the same result

MySQL Query to find users still inside room

Below is my database table, where I will have Check In and Check Out entry records for attending the conference room.
id registration_id roomno day type
1 101 1 2 In
2 103 1 2 In
3 101 1 2 Out
4 105 1 2 In
5 103 1 2 Out
6 101 1 2 In
7 103 1 2 In
8 101 1 2 Out
9 105 1 2 In
10 103 1 2 Out
Now, I want to select those records, which are still attending the conference. Condition is like their last record should be type = In. There can be multiple In/Out entries for each user during a day.
Please let me know the quickest possible MySQL query.
Thanks
Answer which I ended up using:
select * from `registrations_inouts` t
group by t.registration_id
having max(id) = max(case when type = 'In' then id end)
order by rand() limit 1;
Here is one method using not exists:
select *
from t
where t.type = 'In' and
not exists (select 1
from t t2
where t2.registration_id = t.registration_id and t2.type = 'Out'
);
Another method uses conditional aggregation:
select t.registration_id
from t
group by t.registration_id
having max(id) = max(case when type = 'In' then id end);
Note: both of these assume that the ids are assigned sequentially in time, so larger ids are later in time.

mysql compare 2 rows same table

I am trying to compare 2 rows and display the same ones.I did browse but was not able to find the right solution.
Table A
Count status Division
20 A 1
30 B 2
10 c 1
12 z 1
From the above table I want to display whose division is same.
Count status Division
20 A 1
10 c 1
12 z 1
Try this
Select * from TableA
Group By Division
Having Count(*) > 1
Select * from TableA
Group By Division
having Count(*) = 1
Here i used case statement , it worked for me
select CompanyCode ,'Commission Pec', Year
,sum(case when CommissionType='Commission Recevied' then JAN else 0 end)/sum(case when CommissionType='Net Payments from WM' and isnull(JAN,0)<>0 then JAN else 1 end)
from Commission_Consolidate
group by CompanyCode,Year
end

Display results in a particular format MYSQL

I have a table like
ID Name Points
1 A 10
1 A 11
1 B 11
1 B 12
1 C 12
1 C 13
2 A 8
2 A 9
2 B 9
2 B 10
2 C 10
2 C 11
I want my output to look like the following
ID Average(A) Average(B) Average(C)
1 10.5 11.5 12.5
2 8.5 9.5 10.5
The following group by query displays the output but not in above format
Select Avg(Points),ID,name from table group by Name,ID
Thanks
Wrapping your existing query in a subquery will allow you to build out a pivot table around it. The `MAX()
aggregate's purpose is only to eliminate the NULLs produced by the CASE statement, and therefore collapse multiple rows per ID down to one row per ID with a non-NULL in each column.
SELECT
ID,
MAX(CASE WHEN Name = 'A' THEN Points ELSE NULL END) AS `Average (A)`,
MAX(CASE WHEN Name = 'B' THEN Points ELSE NULL END) AS `Average (B)`,
MAX(CASE WHEN Name = 'C' THEN Points ELSE NULL END) AS `Average (C)`
FROM (
SELECT ID, AVG(Points) AS Points, Name FROM yourtable GROUP BY Name, ID
) avg_subq
GROUP BY ID
Here is a live demonstration on SQLFiddle

MySQL query to count non-null values in a single row

I'm trying to put together a MYSQL query that will count the number of Non-Null (or better yet, non-zero) values in select fields in a single row and then sort from lowest to highest (based on the count). For example, I have a table with 5 fields... ID, Name, Score_1, Score_2, Score_3. I want to count how many times the value "0" exists in Score_1, Score_2 and Score_3 for each record, then sort from most non zero values to least.
ID Name Score_1 Score_2 Score_3
1 Dan 8 7 0
2 Joe 0 0 3
3 Chris 0 0 0
4 Mike 4 5 5
I assume the query has to look something like this...
Select ID, Name, Score_1, Score_2, Score_3 where (???) ORDER BY (???)
Output should look like this (ID 4 is displayed first since it has the least amount of non-zero entries)...
ID Name Score_1 Score_2 Score_3
4 Mike 4 5 5
1 Dan 8 7 0
2 Joe 0 0 3
3 Chris 0 0 0
I'm somewhat new to mysql query's, so any help would be greatly appreciated. I thought the COUNT function would help, but that function appears to count columns from all rows. Perhaps there is a way to use the COUNT function and limit it to a singel row so it can be sorted by that row count?
This should do what you want:
SELECT ID, Name, Score_1, Score_2, Score_3
FROM Table1
ORDER BY (Score_1 = 0) + (Score_2 = 0) + (Score_3 = 0)
Result:
ID Name Score_1 Score_2 Score_3
4 Mike 4 5 5
1 Dan 8 7 0
2 Joe 0 0 3
3 Chris 0 0 0
try This:
Select id, Count1, Count2, Count3, Count4
From
(Select
Sum(Case When IsNull(Score_1,0) = 0 Then 1 Else 0 End) Count1,
Sum(Case When IsNull(Score_2,0) = 0 Then 1 Else 0 End) Count2,
Sum(Case When IsNull(Score_3,0) = 0 Then 1 Else 0 End) Count3,
Sum(Case When IsNull(Score_4,0) = 0 Then 1 Else 0 End) Count4
From Table
Group By Id) Z -- This column (Id) better not be the PK for this table!!!
Order By Count1 + Count2 + Count3 + Count4