Shorter CASE ISNULL(qry, '')='' THEN 'no' ELSE 'yes' END - sql

Is there a shorter/better way to write this SQL statement?
Edit: the inner sql select statement is a placeholder, the actual statement is more complex.
SELECT
CASE WHEN
ISNULL((SELECT TOP 1 x FROM y), '') = ''
THEN 'No'
ELSE 'Yes'
END AS BooleanValue
It feels very kludgey because it compares the result of the select statement to null, then sets to an empty string if null; just to check if it is an empty string, and set it to what it actually needs to be: a 'yes' or 'no' string.

Here's one way to do it a bit cleaner.
SELECT
CASE WHEN
(SELECT TOP 1 x FROM y) IS NULL
THEN 'No'
ELSE 'Yes'
END AS BooleanValue
This removes one extra command and should have the same output. I just tested it in sql server 2012.

SELECT ISNULL((SELECT TOP 1 'Yes' FROM x), 'No') as Boolean

Related

BigQuery - How to Select new calculated variable?

How can I select a new variable?
Sample:
Select case when X=1 then 'Y'
else 'N' end as FLAG,
case when FLAG='Y' then 1
else 0 end as Y
from [table]
simply use same case for 2nd variable also for example
Select case when X=1 then 'Y' else 'N' end as FLAG,case when X=1 then '1' else '0' end as Y from [table]
As mention by #Salman ansari, you can just reuse the case for this new variable if your condition is the same.
But lets put a situation where you still want to have that case column as an actual column, you can use with:
with case_data as (
Select id,col1,col2,col3,case when X=1 then 'Y'
else 'N' end as FLAG,
from [table]
)
select id,col1,col2,cole,FLAG,case when FLAG='Y' then 1
else 0 end as Y from [case_data]
By doing that you can display your case column as a column which can be use on the outer with select.
You can explore additional information about case and with usage on:
CASE
WITH
I believe there is no solution in BigQuery. but this can be a work-around.
Select *,
case when FLAG='Y' then 1
else 0 end as Y
from (Select *,
case when X=1 then 'Y'
else 'N' end as FLAG
from [table])

How can I use CASE clause twice in SQL Query

I am trying to apply two conditions in one SQL Query.
(select DISTINCT (
CASE WHEN (
ABC.GemUserID = '99' )
OR ABC.GemUserID != '99'
THEN 'Yes'
ELSE 'No'
END)) AS AllWell
This gives me output as "Yes" where as the CASE is true only for 1 file like below :
Current Result:
99 , Yes
99 , Yes
99 , Yes
Expected Result:
99 , No
99 , No
99 , Yes
I am using the below query but the SQL Query Intellisence is identifying it as wrong.
Wrong Query:
(select DISTINCT (
CASE WHEN ( ABC.GEMUserID = '99' THEN 'Yes' else 'No'
CASE WHEN ( ABC.GEMUserID != '99' THEN 'No' else 'Yes'
END)) AS AllWell
After fixing the above Wrong Query:
(select DISTINCT
(CASE WHEN ABC.GemUserID = '99' THEN 'Yes' else 'No' END),
(CASE WHEN ABC.GemUserID != '99' THEN 'No' else 'Yes' END))
AS AllWell
But I am getting error:
Msg 116, Level 16, State 1, Line 17 Only one expression can be
specified in the select list when the subquery is not introduced with
EXISTS.
How to fix this?
select distinct is -- itself -- part of SQL syntax. The distinct is not a function. It should not be followed by parentheses. So, if I understand your question:
select DISTINCT
( CASE WHEN ABC.GEMUserID = '99' THEN 'Yes' else 'No' END),
( CASE WHEN ABC.GEMUserID <> '99' THEN 'No' else 'Yes' END) as AllWell
Do you plan on giving the first column a name?
select DISTINCT
CASE WHEN ABC.GEMUserID = '99' THEN 'Yes'
ELSE 'No' -- This is automatically When ABC.GEMUserID <> '99'
END AS AllWell
According to the error, your query is a subquery (probably behind IN?) in a larger SQL command. Therefore, it is not possible for such subquery to return more than one column.
So your first query, you've said:
CASE WHEN userID = 99 OR userID != 99
In other words:
CASE WHEN 1=1
This is why it returns yes for everything (not sure what the difference between your current and expected result should be considering that the userID is 99 for all rows).
For your erroneous query, seems you're returning that select in the middle of another select (since you alias it at the end). Due to that, you cannot return more than one column in your nested select. You do not need the second CASE statement, simply change your query to:
(select DISTINCT
CASE WHEN ABC.GemUserID = '99' THEN 'Yes' Else 'No' End) AS AllWell
Assuming that you hold the missing pieces to the query such as the FROM.

SQL Server - Case Statement

I'm almost certain you cannot do this within the context of the case statement, and I haven't been able to find any documentation about it, but is it possible to do the following:
SELECT CASE WHEN testValue > 2
THEN testValue(Without Repeating it) ELSE FailValue)
END
FROM Table
A better more thorough example:
Select CASE WHEN (Foo-stuff+bar) > 2
THEN Conditional statement without >2 Else "Fail"
END
FROM TABLE
I am looking for a way to create a select without repeating the conditional query.
EDIT: Due to a poor example on my part, and the lack of answers I was looking for:
testValue = (Table.A / Table.B) * Table.C Table.D
SELECT CASE WHEN testValue > 2
THEN testValue ELSE FailValue)
END
FROM Table
Like so
DECLARE #t INT=1
SELECT CASE
WHEN #t>0 THEN
CASE
WHEN #t=1 THEN 'one'
ELSE 'not one'
END
ELSE 'less than one'
END
EDIT:
After looking more at the question, I think the best option is to create a function that calculates the value. That way, if you end up having multiple places where the calculation needs done, you only have one point to maintain the logic.
The query can be written slightly simpler, like this:
DECLARE #T INT = 2
SELECT CASE
WHEN #T < 1 THEN 'less than one'
WHEN #T = 1 THEN 'one'
ELSE 'greater than one'
END T
I am looking for a way to create a select without repeating the conditional query.
I'm assuming that you don't want to repeat Foo-stuff+bar. You could put your calculation into a derived table:
SELECT CASE WHEN a.TestValue > 2 THEN a.TestValue ELSE 'Fail' END
FROM (SELECT (Foo-stuff+bar) AS TestValue FROM MyTable) AS a
A common table expression would work just as well:
WITH a AS (SELECT (Foo-stuff+bar) AS TestValue FROM MyTable)
SELECT CASE WHEN a.TestValue > 2 THEN a.TestValue ELSE 'Fail' END
FROM a
Also, each part of your switch should return the same datatype, so you may have to cast one or more cases.
We can use case statement Like this
select Name,EmailId,gender=case
when gender='M' then 'F'
when gender='F' then 'M'
end
from [dbo].[Employees]
WE can also it as follow.
select Name,EmailId,case gender
when 'M' then 'F'
when 'F' then 'M'
end
from [dbo].[Employees]

SQL case with different fields to check from same table

I have the following problem:
I have a select statement that includes a case part. Up til there it is easy the problem is that the case includes a check against another field in the same table.
select h.id,
case h.value
when 'P' then 'test'
when '' then 'failed'
when 'D' then 'passed'
else null end
as info,
b.text,
case h.diag
when h.value = '' [or 'failed' not sure tried both and didn't work]
else h.diag end
as diag1, h.date from valuetab h, texttab b where h.id=b.id
I want to have h.diag only to show values when h.value is not failed.
I always get the mistake that the = should be concat.. but that doesn't make sense in my eyes.
Any ideas??
Thats for all your help.
You can also write a case statement with your expression in a different place i.e.
SELECT CASE WHEN X = 1 THEN 'Y' WHEN X = 2 THEN 'Z'
I think what you want to do is something more like this:
SELECT CASE WHEN h.value = '' THEN h.diag end
Use the other form of case statement, which doesn't specify a column you want to look at:
select case
when column1 = 2 then 'Foo'
when other_column = 'blah' then 'Bar'
end
from table
The problem with using case column1 when... is that it implicitly compares column1 to each when clause. You can't then include a comparison to some other column in it.
You are missing a THEN portion of the WHEN clause, and specifying a condition where you could specify a value:
case h.value
when '' THEN NULL
else h.diag end
Ok got it....
after the 2nd case the "h.diag" must be removed....
so it is
case
when h.value = '' then null
else h.diag end
as diag1,

SQL Query - Return Text based on numeric value

I am trying to work out a query where the query will perform a count (total) on a specific column. If the count is greater than 0, I want to display YES and display NO if the returned count is zero.
So, if I a query as this:
SELECT COUNT(ProblemID)
FROM dbo.ProblemInfo
WHERE (ProblemID IN (100,101,309,305,205,600,500)) AND (DEPID = '10866')
that will actually be a subquery, how do I get the subquery to display "YES" when the returned count is greater than 0 and NO if the count is 0?
I appreciate any insight and help.
select isnull(
SELECT MAX('YES')
FROM dbo.ProblemInfo
WHERE ProblemID IN (100,101,309,305,205,600,500)
AND DEPID = '10866'),
'NO')
This is a trick to return either YES if there's at least one matching row, or null if not.
The wrapping isnull call then turns a null into a NO
Here's an alternate way of querying that.
IF EXISTS(
SELECT *
FROM dbo.ProblemInfo
WHERE (ProblemID IN (100,101,309,305,205,600,500))
AND (DEPID = '10866')
)
BEGIN
SELECT 'Yes'
END
ELSE
BEGIN
SELECT 'No'
END
What I like about this method is that, for enormous data-sets, it should be noticeably faster.
try
SELECT CASE
WHEN (SELECT COUNT(ProblemID) FROM dbo.ProblemInfo WHERE (ProblemID IN (100,101,309,305,205,600,500)) AND (DEPID = '10866')) > 0
THEN 'YES'
ELSE 'NO' END
FROM YourTable
you can use case when.
SELECT
case
when COUNT(ProblemID) = 0 then 'NO'
else 'YES'
end
FROM dbo.ProblemInfo WHERE (ProblemID IN (100,101,309,305,205,600,500)) AND (DEPID = '10866')