SQL SELECT Query with group and distinct - sql

I have table with 4 columns (id, bm, name, act).
I want to retrieve records grouped by bm and count how many records have of every group where act = no and where act = yes at once...
So if I have records:
(Id, bm, name, act)
1, 5, Nik, yes
2, 6, Mike, yes
3, 5, Tom, no
4, 5, Alex, no
Result I need is:
(bm, totalYes, totalNo)
5, 1, 2
6, 1, 0
I guess that everything is possible to retrieve from SQL but I don't know how :(


You can use conditional aggregation to achieve this result:
select
bm,
sum(case when act = 'yes' then 1 else 0 end) as "Count of yes",
sum(case when act = 'no' then 1 else 0 end) as "Count of no"
from t
group by bm;
With some databases, like MySQL, you can reduce the aggregation to sum(act = 'yes'), but the ANSI SQL standard requires the full case expression.
Sample SQL Fiddle


Try following
SELECT SUM(CASE WHEN act = 'no' THEN 1 ELSE 0 END) as NoCount,
SUM(CASE WHEN act = 'yes' THEN 1 ELSE 0 END) YesCount
FROM tbl
GROUP BY gm


Since aggregate functions typically skip nulls, you can create two columns TotalYes and TotalNo, with a value NULL for cases you don't want to include in your count.
Here's what I mean:
SELECT
bm,
COUNT( CASE act WHEN 'yes' THEN 1 ELSE NULL END ) TotalYes,
COUNT( CASE act WHEN 'no' THEN 1 ELSE NULL END ) TotalNo
FROM tbl
GROUP BY bm

Related

Combining multiple rows with the same ID, but different 'Yes'/'No' values for several columns, into one row showing all 'Yes'/'No' values

For the above table, I need to reduce the rows down to one per Filter ID and have all the possible yes/no values showing for that particular Filter Id
for example:
Filter ID
Outpatient Prescriptions
Opioid Outpatient Prescriptions
...
IP Pharmacy Medication Orders - Component Level
1
Yes
Yes
...
No
How is this achieved?

If I understand your question, for each partition of FilterID value, you want any field that has a yes to be aggregated up as 'Yes', otherwise 'No'. If you group by FilterID then you can handle the rollup using a CASE SUM CASE.
SELECT
FilterID,
Field1Response = CASE WHEN SUM(CASE WHEN Field1='Yes' THEN 1 ELSE 0 END) > 1 THEN 'Yes' ELSE 'No' END,
Field2Response = CASE WHEN SUM(CASE WHEN Field2='Yes' THEN 1 ELSE 0 END) > 1 THEN 'Yes' ELSE 'No' END ,
Field3Response = CASE WHEN SUM(CASE WHEN Field3='Yes' THEN 1 ELSE 0 END) > 1 THEN 'Yes' ELSE 'No' END
...
FROM
Data
GROUP BY
FilterID
By the nature of the data, you can also simply use a MAX. This is not a good habit of getting into because the values may change over time, however, if the values are always Y or N then you could simply use MAX:
SELECT
FilterID,
Field1Response = MAX(Field1),
Field2Response = MAX(Field1),
Field3Response = MAX(Field1)
...
FROM
Data
GROUP BY
FilterID

GROUP BY SUM CASE expression

I want to group by account number, but I am running into problems if I get multiple RATE_CD's for an account - I get a NONCOMPLIANT_CNT of 2, but I want it to be only 1 per account even if there is more than 1 RATE_CD.
Below is the SQL I'm playing around with, any ideas on how I can return the NONCOMPLIANT_CNT per account, and not roll up the count if there is more than 1 RATE_CD?
SELECT ID
,ACCOUNT_NBR SUM(CASE
WHEN GROUP_CD = 'RED'
AND TYPE_CD IN ('CHK')
THEN 1
ELSE 0
END) AS 'COMPLIANT_CNT'
,SUM(CASE
WHEN GROUP_CD = 'RED'
AND TYPE_CD IN (
'CN'
,'RN'
)
AND RATE_CD <> 'BLK'
THEN 1
ELSE 0
END) AS 'NONCOMPLIANT_CNT'
,SUM(CASE
WHEN GROUP_CD = 'RED'
AND TYPE_CD IN (
'CN'
,'RN'
,'CHK'
)
THEN 1
ELSE 0
END) AS 'TOTAL_CNT'
FROM DETAIL
LEFT OUTER JOIN RATE_LOOKUP ACCOUNT_NBR = ACCOUNT_NBR
GROUP BY ID
,ACCOUNT_NBR
,RATE_CD

If you only want 1 instead of how many actual, change your SUM() to MAX(). So if they have 5 entries, it would still show as at least 1, otherwise will be 0 for the given column aggregate.

sql case statement IN with group by

I have a 2 column table with the columns : "user_name" and "characteristic". Each user_name may appear multiple times with a different characteristic.
The values in characteristic are:
Online
Instore
Account
Email
I want to write a sql statement that goes like this - but obviously this isn't working:
SELECT user_name,
case
when characteristic in ("online","instore") then 1
else 0
END as purchase_yn,
case
when characteristic in ("online","instore") and
characteristic in ("email",'account') then 1
else 0
END as purchaser_with_account
FROM my_table
GROUP BY user_name;
Essentially the first is a flag where I check for the presence of either value for that user_name.
The Second field is that they meet this criteria AND that they meet the criteria for having either 'email' or 'account'

An example the structure of your data would help better understand what you are trying to accomplish. But I think I get what you are trying to do.
You have to use an aggregate function in order to use a group by.
Something like SUM or AVG.
But you need first to build a pivot of your data and then you could use that pivot to check for your criterias:
This would create a table pivot that shows for each record what criterias are met:
SELECT
user_name,
case when characteristic = "online" then 1 else 0 end as online_yn,
case when characteristic = "instore" then 1 else 0 end as instore_yn,
case when characteristic = "account" then 1 else 0 end as account_yn,
case when characteristic = "email" then 1 else 0 end as email_yn,
FROM my_table
Now what you might wanted to do is to create an averaged version of these entries grouped by user_name and use those averages to create the fields you wanted. For that you need to use the same statement created earlier as an inline table :
Select
user_name,
case when avg(online_yn + instore_yn) >= 1 then 1 else 0 end as purchase_yn,
case when avg(online_yn + instore_yn) >= 1 and avg(email_yn + account_yn) >= 1 then 1 else 0 end as purchaser_with_account
From
(SELECT
user_name,
case when characteristic = "online" then 1 else 0 end as online_yn,
case when characteristic = "instore" then 1 else 0 end as instore_yn,
case when characteristic = "account" then 1 else 0 end as account_yn,
case when characteristic = "email" then 1 else 0 end as email_yn,
FROM my_table) avg_table
group by
user_name;
This should help.
It may not be efficient in terms of performance but you'll get what you want.

You just have to enclose the CASE expressions in COUNT aggregates:
SELECT user_name,
COUNT(case when characteristic in ("online","instore") then 1 END) as purchase_yn,
COUNT(case when characteristic in ("email",'account') then 1 END) as user_with_account
FROM my_table
GROUP BY user_name
If purchase_yn > 0 then you first flag is set. If purchase_yn > 0 and user_with_account > 0 then you second flag is set as well.
Note: You have to remove ELSE 0 from the CASE expressions because COUNT takes into account all not null values.

You haven't mentioned a specific RDBMS, but if SUM(DISTINCT ...) is available the following is quite nice:
SELECT
username,
SUM(DISTINCT
CASE
WHEN characteristic in ('online','instore') THEN 1
ELSE 0
END) AS purchase_yn,
CASE WHEN (
SUM(DISTINCT
CASE
WHEN characteristic in ('online','instore') THEN 1
WHEN characteristic in ('email','account') THEN 2
ELSE 0 END
)
) = 3 THEN 1 ELSE 0 END as purchaser_with_account
FROM
my_table
GROUP BY
username

If I correctly understand, if user have 'online' or 'instore', then for this user you want 1 as purchase_yn column, and if user also have 'email' or 'account', then 1 as purchaser_with_account column.
If this is correct, then one way is:
with your_table(user_name, characteristic) as(
select 1, 'online' union all
select 1, 'instore' union all
select 1, 'account' union all
select 1, 'email' union all
select 2, 'account' union all
select 2, 'email' union all
select 3, 'online'
)
-- below is actual query:
select your_table.user_name, coalesce(max(t1.purchase_yn), 0) as purchase_yn, coalesce(max(t2.purchaser_with_account), 0) as purchaser_with_account
from your_table
left join (SELECT user_name, 1 as purchase_yn from your_table where characteristic in('online','instore') ) t1
on your_table.user_name = t1.user_name
left join (SELECT user_name, 1 as purchaser_with_account from your_table where characteristic in('email', 'account') ) t2
on t1.user_name = t2.user_name
group by your_table.user_name

Average and case in SQL Server 2012

I'd like to have the average of a column when its bigger than zero.
Select Avg(Case when Column > 0 then Column else 0 end) as Avg
but I'm afraid the else clause is not correct. I want to ignore the zero values in the average.

Remove else part from case statement so the values less than 1 will be NULL.
Null values will be eliminated by the Avg aggregate. So you will get the average of values which are greater then 0. Try this.
Select Avg(Case when [Column]>0 then [Column] end) as [Avg]
DEMO
Without else part in case statement (Expected Average)
SELECT Avg(CASE WHEN a > 0 THEN a END) [Avg]
FROM (SELECT 2 a UNION ALL SELECT 2 UNION ALL SELECT -1) bb
Result : 2
With else part in case statement.
SELECT Avg(CASE WHEN a > 0 THEN a ELSE 0 END) [Avg]
FROM (SELECT 2 a UNION ALL SELECT 2 UNION ALL SELECT -1) bb
Result : 1

sql select display row data as columns

I have a sql select query that extracts result as:
login_count login_type
2000 iPhone
7000 browser
But i want the result as:
iphone_login browser_login
2000 7000
i.e. i want to extract row1-col1 as col1 and row2-col2 as col2 using a select query.
My original query is
select count(login_count), login_type from log_table group by login_type;
Thanks,
Gaurav

Try this:
SELECT
SUM( IF(login_type = 'iPhone', 1, 0) ) AS iphone_login,
SUM( IF(login_type = 'browser', 1, 0) ) AS browser_login
FROM log_table

Here is another option that works in MySQL and in other dbms as well.
select sum(case when login_type = 'iPhone' then 1 else 0 end) as iphone_login
,sum(case when login_type = 'browser' then 1 else 0 end) as browser_login
from log_table