If I have a table like :
u_id A B C D
----------------------------------
jud 1 1 0 1
bud 0 0 1 0
cud 1 1 0 1
nud 0 0 1 0
dud 1 0 0 1
aud 0 1 1 0
fud 1 0 1 1
which sql is useful to get output like:
count 0 count 1
-----------------------
A 3 4
B 4 3
C 3 4
D 3 4
Doesn't matter row or columns just need count of a specific value count for multiple columns in a table.
Instead of 0's and 1's it can be specific string values as well as 'yes' or 'no'
Thank you
Use UNION ALL and aggregation. Assuming that the only possible values in the columns are 0 and 1:
SELECT 'A' col, COUNT(*) - SUM(A) count0, SUM(A) count1 FROM mytable
UNION ALL SELECT 'B', COUNT(*) - SUM(B), SUM(B) FROM mytable
UNION ALL SELECT 'C', COUNT(*) - SUM(C), SUM(C) FROM mytable
UNION ALL SELECT 'D', COUNT(*) - SUM(D), SUM(D) FROM mytable
Demo on DB Fiddle:
| col | count0 | count1 |
| --- | ------ | ------ |
| A | 3 | 4 |
| B | 4 | 3 |
| C | 3 | 4 |
| D | 3 | 4 |
If other values than 0/1 are possible, then you can change the SELECTs to, eg 'yes'/'no', then:
SELECT
'A' col,
SUM(CASE WHEN A = 'no' THEN 1 ELSE 0 END) count_no,
SUM(CASE WHEN A = 'yes' THEN 1 ELSE O END) count_yes
FROM mytable
GROUP BY col
UNION ALL SELECT
'B' col,
SUM(CASE WHEN B = 'no' THEN 1 ELSE 0 END),
SUM(CASE WHEN B = 'yes' THEN 1 ELSE 0 END)
FROM mytable
GROUP BY col
UNION ALL SELECT
'C' col,
SUM(CASE WHEN C = 'no' THEN 1 ELSE 0 END),
SUM(CASE WHEN C = 'yes' THEN 1 ELSE 0 END)
FROM mytable
GROUP BY col
UNION ALL SELECT
'D' col,
SUM(CASE WHEN D = 'no' THEN 1 ELSE 0 END),
SUM(CASE WHEN D = 'yes' THEN 1 ELSE 0 END)
FROM mytable
GROUP BY col
If you are okay with a single row, you can do:
select sum(a), sum(1-a), sum(b), sum(1-b), sum(c), sum(1-c), sum(d), sum(1-d)
from t;
The advantage of this approach is that t is read only once. This is even more true if it is a complex view.
With that in mind, you can unpivot this result:
select v.x,
(case when v.x = 'a' then a_0 end) as a_0,
(case when v.x = 'a' then a_1 end) as a_1,
(case when v.x = 'b' then b_0 end) as b_0,
(case when v.x = 'b' then b_1 end) as b_1,
(case when v.x = 'c' then c_0 end) as c_0,
(case when v.x = 'c' then c_1 end) as c_1,
(case when v.x = 'd' then d_0 end) as d_0,
(case when v.x = 'd' then d_1 end) as d_1
from (select sum(a) as a_1, sum(1-a) as a_0,
sum(b) as b_1, sum(1-b) as b_0,
sum(c) as c_1, sum(1-c) as c_0,
sum(d) as d_1, sum(1-d) as d_0
from t
) s cross join
(values ('a'), ('b'), ('c'), ('d')) v(x) -- may require a subquery
You don't mention the database you're using, but in Oracle you can use DECODE and COUNT together to make this reasonably clean:
SELECT 'A' AS FIELD_NAME,
COUNT(DECODE(A, 0, 0, NULL)) AS ZERO_COUNT,
COUNT(DECODE(A, 0, NULL, A)) AS NON_ZERO_COUNT
FROM TEST_TABLE UNION ALL
SELECT 'B', COUNT(DECODE(B, 0, 0, NULL)),
COUNT(DECODE(B, 0, NULL, A))
FROM TEST_TABLE UNION ALL
SELECT 'C', COUNT(DECODE(C, 0, 0, NULL)),
COUNT(DECODE(C, 0, NULL, A))
FROM TEST_TABLE UNION ALL
SELECT 'D', COUNT(DECODE(D, 0, 0, NULL)),
COUNT(DECODE(D, 0, NULL, A))
FROM TEST_TABLE
dbfiddle here
Related
Let's say I've got a table with 4 columns.
Of each column I'd like to know:
the percentage of missing values (null count) and
unique counts
If I have a table with columns A B C and D,
the desired outcome of the situation above would be for example:
Column_Name | PctMissing | UniqueCount
A | 0.15 | 16
B | 0 | 320
C | 0.3 | 190
D | 0.05 | 8
If you know the number of columns, I'd probably just use union all:
select 'a' as Column_Name,
1.0*count(case when a is null then 1 end)/count(*) as PctMissing,
count(distinct a) as UniqueCount
from t
union all
select 'b' as Column_Name,
1.0*count(case when b is null then 1 end)/count(*) as PctMissing,
count(distinct b) as UniqueCount
from t
union all
select 'c' as Column_Name,
1.0*count(case when c is null then 1 end)/count(*) as PctMissing,
count(distinct c) as UniqueCount
from t
union all
select 'd' as Column_Name,
1.0*count(case when d is null then 1 end)/count(*) as PctMissing,
count(distinct d) as UniqueCount
from t
Fiddle Demo
Depending on your database, there are other approaches, but can be more confusing than union all.
I would write this as:
select 'a' as column_name,
avg(case when a is null then 1.0 else 0 end) as missing_ratio,
count(distinct a) as unique_count
from t
union all
select 'b' as column_name,
avg(case when b is null then 1.0 else 0 end) as missing_ratio,
count(distinct b) as unique_count
from t
union all
select 'c' as column_name,
avg(case when c is null then 1.0 else 0 end) as missing_ratio,
count(distinct c) as unique_count
from t
union all
select 'd' as column_name,
avg(case when d is null then 1.0 else 0 end) as missing_ratio,
count(distinct d) as unique_count
from t;
Not sure if the title made sense.
But this what I need, I am bad at sql:
I have table with the following data
ID| Value
------ | ------
1| A
1| B
1| C
1| D
2| A
2| B
2| C
I need O/P as
2 A
2 B
2 C
Using Select id where value in (A,B,C) and Not in (D)
is giving me o/p as
1 A
1 B
1 C
2 A
2 B
2 C
Need to select Id's having A,B,C but not D.
If you want to get rows which has one or more value in A, B, C, but not D:
select *
from your_table
where value in ('A', 'B', 'C')
and id not in (
select id
from your_table
where value = 'D'
);
If you want that all the three values A, B, C must be present for that id and but not D.
select id,
value
from (
select t.*,
count(distinct value) over (partition by id) n
from your_table t
where value in ('A', 'B', 'C')
and id not in (
select id
from your_table
where value = 'D'
)
)
where n = 3;
If you want to get rows having only A, B, C (and all of them present) then use :
select id,
value
from (
select t.*,
count(case
when value not in ('A', 'B', 'C')
then 1
end) over (partition by id) n,
count(distinct case
when value in ('A', 'B', 'C')
then value
end) over (partition by id) n2
from your_table t
)
where n = 0
and n2 = 3;
You can use conditional aggregation in a HAVING clause to filter across rows for each id:
SELECT id
FROM table1
GROUP BY id
HAVING MAX(CASE WHEN value = 'A' THEN 1 ELSE 0 END) = 1
AND MAX(CASE WHEN value = 'B' THEN 1 ELSE 0 END) = 1
AND MAX(CASE WHEN value = 'C' THEN 1 ELSE 0 END) = 1
AND MAX(CASE WHEN value = 'D' THEN 1 ELSE 0 END) = 0
This will show you which id values meet your criteria, and if you need you can put this in a subquery and join it to your table to get all the rows for that id:
SELECT a.*
FROM table1 a
JOIN ( SELECT id
FROM table1
GROUP BY id
HAVING MAX(CASE WHEN value = 'A' THEN 1 ELSE 0 END) = 1
AND MAX(CASE WHEN value = 'B' THEN 1 ELSE 0 END) = 1
AND MAX(CASE WHEN value = 'C' THEN 1 ELSE 0 END) = 1
AND MAX(CASE WHEN value = 'D' THEN 1 ELSE 0 END) = 0
) b
ON a.id = b.id
From your question, I understood that to find the count of Value column where the values are A, B, C but Value not equal to D. Then simply put those 3 value in IN operator. I will retrieve the result set without D.
Query
SELECT COUNT(Value) count, Value
FROM your_table_name
WHERE Value in ('A', 'B', 'C')
GROUP BY Value;
select id, value
from my_table
where value in ('A','B','C')
and id = 2
I have a table like this:
id | Values
------------------
1 | a
1 | b
1 | c
1 | d
1 | e
2 | a
2 | a
2 | c
2 | c
2 | e
3 | a
3 | c
3 | b
3 | d
Now I want to know which id contains at least one of a, one of b and one of c.
This is the result I want:
id
--------
1
3
One method is aggregation with having:
select id
from t
where values in ('a', 'b', 'c')
group by id
having count(distinct values) = 3;
If you wanted more flexibility with the counts of each value:
having sum(case when values = 'a' then 1 else 0 end) >= 1 and
sum(case when values = 'b' then 1 else 0 end) >= 1 and
sum(case when values = 'c' then 1 else 0 end) >= 1
You can use grouping:
SELECT id
FROM your_table
GROUP BY id
HAVING SUM(CASE WHEN value = 'a' THEN 1 ELSE 0 END) >= 1
AND SUM(CASE WHEN value = 'b' THEN 1 ELSE 0 END) = 1
AND SUM(CASE WHEN value = 'c' THEN 1 ELSE 0 END) = 1;
or using COUNT:
SELECT id
FROM your_table
GROUP BY id
HAVING COUNT(CASE WHEN value = 'a' THEN 1 END) >= 1
AND COUNT(CASE WHEN value = 'b' THEN 1 END) = 1
AND COUNT(CASE WHEN value = 'c' THEN 1 END) = 1;
I have a table like below -
Student ID | History | Maths | Geography
1 A B B
2 C C E
3 D A B
4 E D A
How to find out how many students got A in history, B in maths and E in Geography with a single sql query ?
If you want to get number of students who got A in History in one column, number of students who got B in Maths in second column and number of students who got E in Geography in third then:
select
sum(case when [History] = 'A' then 1 else 0 end) as HistoryA,
sum(case when [Maths] = 'B' then 1 else 0 end) as MathsB,
sum(case when [Geography] = 'E' then 1 else 0 end) as GeographyC
from Table1
If you want to count students who got A in history, B in maths and E in Geography:
select count(*)
from Table1
where [History] = 'A' and [Maths] = 'B' and [Geography] = 'E'
If you want independent counts use:
SELECT SUM(CASE WHEN Condition1 THEN 1 ELSE 0 END) AS 'Condition1'
,SUM(CASE WHEN Condition2 THEN 1 ELSE 0 END) AS 'Condition2'
,SUM(CASE WHEN Condition3 THEN 1 ELSE 0 END) AS 'Condition3'
FROM YourTable
If you want multiple conditions for one count use:
SELECT COUNT(*)
FROM YourTable
WHERE Condition1
AND Condition2
AND Condition3
It sounds like you want multiple independent counts:
SELECT SUM(CASE WHEN History = 'A' THEN 1 ELSE 0 END) AS 'History A'
,SUM(CASE WHEN Maths = 'B' THEN 1 ELSE 0 END) AS 'Maths B'
,SUM(CASE WHEN Geography = 'E' THEN 1 ELSE 0 END) AS 'Geography E'
FROM YourTable
You can try to select from multiple select statements
SELECT t1.*, t2.*, t3.* FROM
(SELECT COUNT(*) AS h FROM students WHERE History = 'A') as t1,
(SELECT COUNT(*) AS m FROM students WHERE Maths = 'B') as t2,
(SELECT COUNT(*) AS g FROM students WHERE Geography = 'E') as t3
create table t(a int, b int);
insert into t values (1,1),(1,2),(1,3),(2,1),(2,2),(2,3),(3,1),(3,2),(3,3);
select * from t;
a | b
----------
1 | 1
1 | 2
1 | 3
2 | 1
2 | 2
2 | 3
3 | 1
3 | 2
3 | 3
select
max(case when a = 1 then b else 0 end) as q,
max(case when b = 1 then a else 0 end) as c,
(
max(case when a = 1 then b else 0 end)
+
max(case when b = 1 then a else 0 end)
) as x
from t
Is it possible to do something like this?
select
max(case when a = 1 then b else 0 end) as q,
max(case when b = 1 then a else 0 end) as c,
(q + c) as x
from t
You can't use the ALIAS that was given on the same level of the SELECT clause.
You have two choices:
by using the expression directly
query:
select
max(case when a = 1 then b else 0 end) as q,
max(case when b = 1 then a else 0 end) as c,
(max(case when a = 1 then b else 0 end) + max(case when b = 1 then a else 0 end)) as x
from t
by wrapping in a subquery
query:
SELECT q,
c,
q + c as x
FROM
(
select
max(case when a = 1 then b else 0 end) as q,
max(case when b = 1 then a else 0 end) as c
from t
) d
Also in SQLServer2005+ you can use CTE
;WITH cte AS
(
select max(case when a = 1 then b else 0 end) as q,
max(case when b = 1 then a else 0 end) as c
from t
)
SELECT q, c, q + c as x
FROM cte
You can't do that unfortunately.
The ALIAS can not be used in the same level where you created them.
A temporary table is necessary, i think.