how to convert the output of sub query into numeric - sql

Question

select rptName
from RptTable
where rpt_id in (
select LEFT(Reports, NULLIF(LEN(Reports)-1,-1))
from repoAccess1
where uid = 'VIKRAM'
)
this is my sql query In which i have use the sub query to access selected field
in this sub query returns
select LEFT(Reports, NULLIF(LEN(Reports)-1,-1))
from repoAccess1
where uid = 'VIKRAM'
Returns
1,2
that means the query should be like
select rptName
from RptTable where rpt_id in (1,2)
But i m getting this error
Msg 8114, Level 16, State 5, Line 1
Error converting data type nvarchar to numeric.
could anyone tell me ow to modify to get exact ans

Answer 1

It's a little hard to tell without the concrete table definitions, but I'm pretty sure you're trying to compare different data types to each other. If this is the case you can make use of the CAST or the CONVERT function, for example:
SELECT
[rptName]
FROM [RptTable]
WHERE [rpt_id] IN
(
SELECT
CONVERT(int, LEFT([Reports], NULLIF(LEN([Reports]) - 1, -1)))
FROM [repoAccess1]
WHERE [uid] = 'VIKRAM'
)
UPDATE: Since you have updated your question: The LEFT function returns results of either varchar or nvarchar data type. So the resulting query would be
SELECT
[rptName]
FROM [RptTable]
WHERE [rpt_id] IN('1', '2')
Please note the apostrophes (is this the correct term?) around the values. Since [rpt_id] seems to be of data type int the values cannot implicitly be converted. And that's where the aforementioned CAST or CONVERT come into play.

Answer 2

If I understand correctly, the subquery is returning a single row with a value of '1,2'. This is not a number, hence the error.
Before continuing, let me emphasize that storing values in comma delimited string is not the SQL-way of doing things. You should have one row per id, with proper types and foreign keys defined.
That said, sometimes we are stuck with other people's really bad design decisions. If this is the case, you can use LIKE:
select rptName
from RptTable r
where exists (select 1
from repoAccess1 a
where a.uid = 'VIKRAM' and
',' + a.reports + ',' like '%,' + cast(r.rpt_id as varchar(255)) + ',%'
);

Answer 3

select rptName
from RptTable
where rpt_id in (
select CAST(LEFT(Reports, NULLIF(LEN(Reports)-1,-1)) AS INT) as Val
from repoAccess1
where uid = 'VIKRAM'
)

Answer 4

Your query would work fine when (LEFT(Reports, NULLIF(LEN(Reports)-1,-1)) ) returns either 1 or 2 since SQL Server implicitly converts the varchar value to numeric.
It seems there might be a data issue. One of the data returned by LEFT function is non-numeric. In order to find that particular record you can use isnumeric function. Try like this,
SELECT rptName
FROM RptTable
WHERE rpt_id IN (
SELECT LEFT(Reports, NULLIF(LEN(Reports) - 1, - 1))
FROM repoAccess1
WHERE uid = 'VIKRAM'
AND ISNUMERIC(LEFT(Reports, NULLIF(LEN(Reports) - 1, - 1))) = 1
)