Returning a default value - sql

Question

I am trying to return a default value if no such record exists for the given parameters. Here's the sql query:
DECLARE #List VARCHAR(max)
DECLARE #date VARCHAR(max)
SET #List = '''4401366'',''3115880'''
SET #date = '''2018-02-09 00:00:00.000'''
DECLARE #SQL NVARCHAR(max)
SET #SQL = N'
select EmpNo, attendanceStatus =
CASE
WHEN AttDate is null then ''false''
WHEN max(AttTimeIn) is null and max(AttTimeOut) is null THEN ''false''
WHEN max(AttTimeIn) is not null and max(AttTimeOut) is not null then(case when (max(AttTimeIn) < max(AttTimeOut)) then ''false'' else ''true'' end)
WHEN max(AttTimeIn) is not null and max(AttTimeOut) is null THEN ''true''
else ''false''
end
from tablename
where empNo in (' +#list+ ') AND AttDate = ('+ #date +')
group by EmpNo, AttDate'
EXEC sp_executesql #SQL
To be more specific, i want attendanceStatus to return false in case no such record exists for the given date (for each employee). How can I achieve this?

Answer 1

I believe you need something like this, but without data it is difficult to test:
SET #SQL = N'
SELECT T0.EmpNo
, attendanceStatus = CASE
WHEN T1.empNo is null
THEN ''false''
WHEN max(T1.AttTimeIn) is null and max(T1.AttTimeOut) is null
THEN ''false''
WHEN max(T1.AttTimeIn) is not null and max(T1.AttTimeOut) is not null
THEN(CASE WHEN (max(T1.AttTimeIn) < max(T1.AttTimeOut))
THEN ''false'' else ''true'' END)
WHEN max(T1.AttTimeIn) is not null and max(T1.AttTimeOut) is null
THEN ''true''
ELSE ''false''
END
FROM tablename T0
LEFT JOIN tablename T1
ON T1.empNo = T0.empNo
AND T1.AttDate = ('+ #date +')
WHERE T0.empNo in (' +#list+ ')
GROUP BY T0.EmpNo
, T1.AttDate
'

Answer 2

you can try this.
DECLARE #List VARCHAR(max)
DECLARE #date VARCHAR(max)
SET #List = '''4401366'',''3115880'''
SET #date = '''2018-02-09 00:00:00.000'''
DECLARE #SQL NVARCHAR(max)
SET #SQL = N'
select EmpNo, attendanceStatus =
CASE WHEN AttDate = ('+ #date +') THEN
CASE
WHEN max(AttTimeIn) is null and max(AttTimeOut) is null THEN ''false''
WHEN max(AttTimeIn) is not null and max(AttTimeOut) is not null then(case when (max(AttTimeIn) < max(AttTimeOut)) then ''false'' else ''true'' end)
WHEN max(AttTimeIn) is not null and max(AttTimeOut) is null THEN ''true''
ELSE ''false''
END
ELSE ''false'' END
from tablename
where empNo in (' +#list+ ')
group by EmpNo, AttDate'
EXEC sp_executesql #SQL

Answer 3

this should work
DECLARE #List VARCHAR(max)
DECLARE #date VARCHAR(max)
SET #List = '''4401366'',''3115880'''
SET #date = '''2018-02-09 00:00:00.000'''
DECLARE #SQL NVARCHAR(max)
SET #SQL = N'
--check if employee exists
with empTable as (
SELECT DISTINCT EmpNo
FROM tablename
WHERE empNo in (' +#list+ '))
select Et.EmpNo, attendanceStatus =
CASE
WHEN T.AttDate is null then ''false''
WHEN max(T.AttTimeIn) is null and max(T.AttTimeOut) is null THEN ''false''
WHEN max(T.AttTimeIn) is not null and max(T.AttTimeOut) is not null then(case when (max(T.AttTimeIn) < max(T.AttTimeOut)) then ''false'' else ''true'' end)
WHEN max(T.AttTimeIn) is not null and max(T.AttTimeOut) is null THEN ''true''
else ''false''
end
from
empTable eT
LEFT JOIN tablename T ON
et.EmpNo=T.EmpNo
where T.AttDate = ('+ #date +')
group by et.EmpNo, T.AttDate'
EXEC sp_executesql #SQL

Answer 4

I have rewritten your code, simplified your case statement and removed some code
AttDate is null then 'false'
AttDate will never be null because it is included in the where clause
I also changed the data type for #date and made it into a parameterized query for date. Your script is still prone to sql injection because of #List. This can be avoided by splitting it into a table.
I am not sure what you want to replace with a default value. But here is the improved script:
DECLARE #List VARCHAR(max)
DECLARE #date DATE
SET #List = '''4401366'',''3115880'''
SET #date = '2018-02-09'
DECLARE #SQL NVARCHAR(max)
SET #SQL = N'
SELECT coalesce(EmpNo, ''default'') EmpNo,
CASE WHEN i is not null and (i >= o or o is null) THEN ''true'' ELSE ''false'' END
FROM
(
SELECT
Empno,
max(AttTimeIn) over (partition by EmpNo) i,
max(AttTimeOut) over (partition by EmpNo)o
FROM tablename
WHERE empNo in (' +#list+ ') AND AttDate = #date
GROUP BY EmpNo, AttDate
) x
GROUP BY EmpNo'
EXEC sp_executesql #SQL, N'#date date', #date