I have two tables as below
tbl1
id qNum
1 1
2 2
3 3
tbl2
id qNum displayNum
1 1 3
2 2 1
3 2 2
4 2 4
Ideally I need a sql results to look like this
qNum display1 display2 display3 display4
1 0 0 1 0
2 1 1 0 1
3 0 0 0 0
I have tried the following sql but this was not correct
SELECT
tbl1.qNum,
CASE when tbl2.displayNum=1 then 1 else 0 end AS filter1,
CASE when tbl2.displayNum=2 then 1 else 0 end AS filter2,
CASE when tbl2.displayNum=3 then 1 else 0 end AS filter3,
CASE when tbl2.displayNum=4 then 1 else 0 end AS filter4,
CASE when tbl2.displayNum=5 then 1 else 0 end AS filter5
FROM
tbl1
Left Join tbl2 ON tbl1.qNum = tbl2.qNum
GROUP BY
tbl1.qNum
Could anyone help a little please!!
You have use MAX function to pivot the table
Try this:
SELECT tbl1.qNum,
MAX(CASE WHEN tbl2.displayNum=1 THEN 1 ELSE 0 END) AS filter1,
MAX(CASE WHEN tbl2.displayNum=2 THEN 1 ELSE 0 END) AS filter2,
MAX(CASE WHEN tbl2.displayNum=3 THEN 1 ELSE 0 END) AS filter3,
MAX(CASE WHEN tbl2.displayNum=4 THEN 1 ELSE 0 END) AS filter4,
MAX(CASE WHEN tbl2.displayNum=5 THEN 1 ELSE 0 END) AS filter5
FROM tbl1
LEFT JOIN tbl2 ON tbl1.qNum = tbl2.qNum
GROUP BY tbl1.qNum
Your query is almost correct, you're just missing an aggregate function:
SELECT
tbl1.qNum,
MAX(CASE when tbl2.displayNum=1 then 1 else 0 end) AS filter1,
MAX(CASE when tbl2.displayNum=2 then 1 else 0 end) AS filter2,
MAX(CASE when tbl2.displayNum=3 then 1 else 0 end) AS filter3,
MAX(CASE when tbl2.displayNum=4 then 1 else 0 end) AS filter4,
MAX(CASE when tbl2.displayNum=5 then 1 else 0 end) AS filter5
FROM
tbl1
Left Join tbl2 ON tbl1.qNum = tbl2.qNum
GROUP BY
tbl1.qNum
The columns you select should always be either in the group by clause or an aggregate function should be applied to them. A group by "collapses" a group of rows and if you don't have an aggregate function on a column (which is not in the group by) a random row of that group is displayed.
Here you can read about the different aggregate functions: GROUP BY (Aggregate) Functions
The MAX() function in our case here returns the greatest value (note: not the row with the greatest value. You can also have a query like this: select min(col), max(col) from whatever).
I just want to point out that in MySQL, you can simplify the expression. It doesn't need a case statement because booleans are treated as integers with values of 0 and 1:
SELECT tbl1.qNum,
MAX(tbl2.displayNum = 1) AS filter1,
MAX(tbl2.displayNum = 2) AS filter2,
MAX(tbl2.displayNum = 3) AS filter3,
MAX(tbl2.displayNum = 4) AS filter4,
MAX(tbl2.displayNum = 5) AS filter5
FROM tbl1 Left Join
tbl2
ON tbl1.qNum = tbl2.qNum
GROUP BY tbl1.qNum;
Normally, I prefer going with ANSI standard syntax. I do, however, find this easier to read than the case syntax.
Also, you may not need tbl1 for the query, if all values you are interested in are already in tbl2.
Related
I am new in sql. I want to count something like:
Select count(*) from table where col1= x and col2=x and Col3=x.
I need to count the same value in all different column.
Any help will be appreciated.
You can use conditional aggregation :
Select sum(case when col1='x' then 1 else 0 end) as count_col1,
sum(case when col2='x' then 1 else 0 end) as count_col2,
sum(case when col3='x' then 1 else 0 end) as count_col3
from tab;
If you want to have sum of these count values, consider the above query as an inner and use the following :
Select q.*,
q.count_col1 + q.count_col2 + q.count_col3 whole_sum
from
(
Select sum(case when col1='x' then 1 else 0 end) as count_col1,
sum(case when col2='x' then 1 else 0 end) as count_col2,
sum(case when col3='x' then 1 else 0 end) as count_col3
from tab
) q
Rextester Demo
I'm trying to understand how to count mysql row's according to HAVING.
SELECT COUNT(*),
SUM(CASE WHEN sentby='$user_id' AND hiddenbysentby=0 THEN 1 ELSE 0 END) as sentbyuser,
SUM(CASE WHEN sentto='$user_id' AND hiddenbysentto=0 THEN 1 ELSE 0 END) as senttouser
FROM cb_users.user_pm
WHERE title LIKE '%$search%'
HAVING senttouser = 1 OR sentbyuser = 1
I want to count rows that are matching these criteria
SUM(CASE WHEN sentby='$user_id' AND hiddenbysentby=0 THEN 1 ELSE 0 END)
SUM(CASE WHEN sentto='$user_id' AND hiddenbysentto=0 THEN 1 ELSE 0 END)
I have second function that display this data without COUNT(*), and it works fine.
But this query selects all rows no matter if hiddenbysentby = 1 or 0 AND hiddenbysentto = 1 or 0
You should change your HAVING clause to:
HAVING senttouser >= 1 OR sentbyuser >= 1
When you are summing rows, your values are going to equal the total number of rows located for each, therefore, unless you only had exactly one row that meets your criteria, you won't get the result you're looking for.
You should move condition by hiddenbysentby and hiddenbysentto fields in WHERE clause and add a condition by user id
SELECT COUNT(*),
SUM(CASE WHEN sentby='$user_id' THEN 1 ELSE 0 END) as sentbyuser,
SUM(CASE WHEN sentto='$user_id' THEN 1 ELSE 0 END) as senttouser
FROM cb_users.user_pm
WHERE title LIKE '%$search%' AND (hiddenbysentby=0 AND sentby='$user_id') OR (hiddenbysentto=0 AND sentto='$user_id')
HAVING senttouser = 1 OR sentbyuser = 1
I have a table below:
Item Status1 Status2
-----------------------------
A Good NULL
A Good NULL
A Good NULL
A Bad Good
B Bad Good
B Good NULL
C Good NULL
C Good NULL
C Good NULL
D Bad Good
Now, I'm thinking off writing a query which gives me the result below:
Item Good Bad
-----------------------------
A 4 1
B 2 1
C 3 0
D 1 1
Distinct in the Item column and the count of Good and Bad for each Item where NULL is not counted.
The column name can be of anything (I just kept it as Good and Bad in my second table).
Any suggestions/ideas on how to achieve my desired results?
Use UNION ALL & do aggregation :
select item, sum(status = 'good'), sum(status = 'bad')
from (select item, status1 as status
from table t
union all
select item, status2
from table t
) t
group by item;
You can use union all and conditional aggregation
select item, count(case when status1='good' then 1 end) as good,
count(case when status1='bad' then 1 end) as bad
from
(
select item , status1 from tablename
union all
select item , status2 from tablename
)A group by item
use union and case when
select Item, sum(case when status = 'good' then 1 else 0 end) as good,
sum ( case when status = 'bad' then 1 else 0 end) as bad
from (select Item, Status1 as status
from table_name
union all
select Item, Status2
from table_name
) t
group by Item;
There's no need for UNION, simply apply some logic.
select Item
,sum(case when Status1 = 'Good' then 1 else 0 end +
case when Status2 = 'Good' then 1 else 0 end) as good
,sum(case when Status1 = 'Bad' then 1 else 0 end +
case when Status2 = 'Bad' then 1 else 0 end) as bad
from tab
group by Item
or
select Item
,count(case when Status1 = 'Good' then 1 end) +
count(case when Status2 = 'Good' then 1 end) as good
,count(case when Status1 = 'Bad' then 1 end) +
count(case when Status2 = 'Bad' then 1 end) as good
from tab
group by Item
You can use sub-query and then apply sum function in outer query
select distinct(item) as item, sum(S1G+S2G) as Good,sum(S1B+S2B) as Bad from ( select item, CASE WHEN status1 ='Good' THEN 1 ELSE 0 END as S1G, CASE WHEN status2 ='Good' THEN 1 ELSE 0 END as S2G, CASE WHEN status2 ='Bad' THEN 1 ELSE 0 END as S2B, CASE WHEN status1 ='Bad' THEN 1 ELSE 0 END as S1B from t1 ) as b group by item
Here is demo
i have a query like below
select project_task_id,
status_id,
sum(case when StatusID=1 then 1 else 0 end) as task_id=1,
sum(case whenStatusID=2 then 1 else 0 end) as task_id=2,
sum(case when StatusID=3 then 1 else 0 end) as task_id=3,
sum(case when StatusID=4 then 1 else 0 end) as task_id=4,
sum(case when StatusID=5 then 1 else 0 end) as task_id=5,
sum(case when StatusID=6 then 1 else 0 end) as task_id=6,
sum(case when StatusID=7 then 1 else 0 end) as task_id=7,
from"Projects".work_unit_status
group by project_task_id,status_id;
I'm getting the below attached output:
https://i.stack.imgur.com/1wfD1.png
and I want to get the below expected output:
https://i.stack.imgur.com/Zql9z.png
include zero's if the status_id is blank
please any one help on this
Try this: use the addition of all sum column
select project_task_id,status_id,
isnull(sum(case when StatusID=1 then 1 else 0 end),0)+
isnull(sum(case whenStatusID=2 then 1 else 0 end),0) +
isnullsum(case when StatusID=3 then 1 else 0 end),0) +
isnullsum(case when StatusID=4 then 1 else 0 end),0)+
isnullsum(case when StatusID=5 then 1 else 0 end),0) +
isnullsum(case when StatusID=6 then 1 else 0 end),0) +
isnullsum(case when StatusID=7 then 1 else 0 end),0) as count_status
from"Projects".work_unit_status group by project_task_id,status_id
use in with your case
with t1 as (
select project_task_id,
status_id,
sum(case when StatusID in (1,2,3,4,5,6,7) then 1 else 0)
as sum_s
from "Projects".work_unit_status
group by project_task_id,status_id
) ,
t2 as
(
select * from (
select 1 as statusid
union
select 2
union
select 3
union
select 4
union
select 5
union
select 6
union
select 7 ) t
) select t1.project_task_id,
t2.statusid,
case when t1.sum_s>0 or not null
then sum_s else 0 end as total
t2 full join t1 on t2.statusid=t1.status_id
Without knowing the exact table structure I assumed that status_id and statusId refer to the same column. (If they are different columns, we need to use StatusId in the COUNT.)
Based on the expected output, you want to count the status_id and group by project_task_id. To make sure that every status is represented for every task, first, we need to create a subquery of all possible project_task_id/status_id combinations. Then we use that with the aggregate values of the original table.
select
ps.project_task_id,
ps.status_id,
count(w.status_id) as total
from (
select distinct
project_task_id,
s.status_id
from work_unit_status
cross join (select distinct status_id from work_unit_status) s
) ps
left join work_unit_status w
on ps.project_task_id = w.project_task_id and ps.status_id = w.status_id
group by
ps.project_task_id,
ps.status_id
If you really need to hardcode the statuses from 1 to 7, use the query below.
select
ps.project_task_id,
ps.status_id,
count(w.status_id) as total
from (
select distinct
project_task_id,
s.status_id
from work_unit_status
cross join (
select 1 as status_id
union select 2
union select 3
union select 4
union select 5
union select 6
union select 7
) s
) ps
left join work_unit_status w
on ps.project_task_id = w.project_task_id and ps.status_id = w.status_id
group by
ps.project_task_id,
ps.status_id
order by
ps.project_task_id,
ps.status_id
SELECT NAMA_DUN,
COUNT(case when ((RIGHT(noMyKid, 1))% 2) = 0 then 1 else 0 end) AS FEMALE,
COUNT(case when ((RIGHT(noMyKid, 1))% 2) = 1 then 1 else 0 end) AS MALE,
COUNT(DISTINCT(noMyKid)) as jumlah
FROM mohon
LEFT JOIN dun ON dun.KOD_DUN=mohon.dun_nama
WHERE status_proses = 'diproses'
AND concat('20', substr(noMyKid, 1, 2)) = '2008'
AND status_mohon = 'Layak'
AND status_semak = '1'
AND (
status_bayar = ''
OR status_bayar = 'Belum'
OR status_bayar = 'Sudah')
AND (
status_terima = ''
OR status_terima = 'Terima'
) GROUP BY dun_nama
ORDER BY NAMA_DUN
This is my mysql code. why is my 'COUNT CASE WHEN' give the same output for female and male column.
Usually COUNT() is used to count rows and is therefore very often used in the form COUNT(*). When you use a field (or anything else) as a parameter into the COUNT() it counts 1 for every no NULL value.
In your case all your values are not NULL (they are either 1 or 0) and consequently you end up with the same results.
So Abhik Chakraborty is right, use SUM() and everything should be fine.
The COUNT() function does only recognize non-null values, so when using case expressions such as you have here, you can explicitly return NULL where needed
SELECT NAMA_DUN,
COUNT(case when ((RIGHT(noMyKid, 1))% 2) = 0 then 1 else NULL end) AS FEMALE,
COUNT(case when ((RIGHT(noMyKid, 1))% 2) = 1 then 1 else NULL end) AS MALE,
COUNT(DISTINCT(noMyKid)) as jumlah
OR, implicitly return NULL by ignoring the else condition
SELECT NAMA_DUN,
COUNT(case when ((RIGHT(noMyKid, 1))% 2) = 0 then 1 end) AS FEMALE,
COUNT(case when ((RIGHT(noMyKid, 1))% 2) = 1 then 1 end) AS MALE,
COUNT(DISTINCT(noMyKid)) as jumlah
OR, mimic the effect of count by using SUM() provided you do use 1 and 0 (or 1 and NULL)
SELECT NAMA_DUN,
SUM(case when ((RIGHT(noMyKid, 1))% 2) = 0 then 1 else 0 end) AS FEMALE,
SUM(case when ((RIGHT(noMyKid, 1))% 2) = 1 then 1 else 0 end) AS MALE,
COUNT(DISTINCT(noMyKid)) as jumlah