if exists in sql within a subquery - sql

Question

I am trying to execute the following query to check the records from the 4 tables and then calling a function,but i get an error near the brackets.It works fine if I use case,but exits when the first condition is met. I need to evaluate for all the tables in the 4 IF's:
select account_id,
(
if exists (select account_id from [dbo].[TEST_R6])
Begin
select dbo.make_indicator(cent,chem,co,dim,lg,pl,strs,vis) + space(1) + 'rr'
End
if exists (select account_id from tbl_noR6)
begin
select dbo.make_indicator(acent,chem,co,dim,lg,pl,str,vis) + space(2) + 'cc'
end
if exists (select account_id from tbl_acct)
begin
select dbo.make_indicator(cent,chem,co,dim,lg,pl,str,vis) + space(3) + 'pp'
end
if exists (select account_id from test_con)
begin
select dbo.make_indicator(cent,chem,co,dim,lg,pl,str,vis) + space(4) + 'no'
end
)as value from CRS_PRODLINE
code works partially with case statement and gives output only for the first case is met and does not check for the others:
DECLARE #cols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX);
SET #cols = STUFF((SELECT distinct ',' + QUOTENAME(c.A_NAME)
FROM TEST_DEL c
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
SET #query = 'SELECT account_id, ' + #cols + ' from
(select account_id,
(case
when exists (select account_id from [dbo].[TEST_R6])
then
dbo.make_indicator(acent,chem,co,dim,lg,pl,str,vis) + space(1)
when exists (select account_id from tbl_noR6)
then
dbo.make_indicator(acent,chem,co,dim,lg,pl,str,vis) + space(2)
when exists (select account_id from tbl_acct)
then
dbo.make_indicator(acent,chem,co,dim,lg,pl,str,vis) + space(2)
end) as value,
assay_name
from CRS_PRODLINE
) x
pivot
(
MAX(newvalue)
for a_name in (' + #cols + ')
) p '
execute(#query)

Answer 1

Based on your comment that CASE only evaluates once being a problem, this should build a string of all the applicable cases.
select account_id,
(
''
+
case when exists (select account_id from dbo.[TEST_R6]) THEN select dbo.make_indicator(cent,chem,co,dim,lg,pl,strs,vis) + space(1) + 'rr' ELSE '' END
+
case when exists (select account_id from dbo.tbl_noR6) THEN select dbo.make_indicator(acent,chem,co,dim,lg,pl,str,vis) + space(2) + 'cc' ELSE '' END
+
case when exists (select account_id from dbo.tbl_acct) THEN select dbo.make_indicator(cent,chem,co,dim,lg,pl,str,vis) + space(3) + 'pp' ELSE '' END
+
case when exists (select account_id from dbo.test_con) THEN select dbo.make_indicator(cent,chem,co,dim,lg,pl,str,vis) + space(4) + 'no' ELSE '' END
) as value
from CRS_PRODLINE

Answer 2

First of all, if there is any record in the table your exists clause will return true. I will assume that this is intentional and you are not trying to match on a specific account_id.
If you want to use this structure you will have to use dynamic SQL. Something like this:
DECLARE #Sql VARCHAR(8000)
IF EXISTS (SELECT account_id FROM tbl_noR6)
BEGIN
SET #Sql = 'select dbo.make_indicator(acent,chem,co,dim,lg,pl,str,vis) + space(2) + ''cc'''
SET #Sql = #Sql + ')as value from CRS_PRODLINE'
EXEC #Sql
END
IF EXISTS (SELECT account_id FROM tbl_acct)
BEGIN
SET #Sql = 'select dbo.make_indicator(cent,chem,co,dim,lg,pl,str,vis) + space(3) + ''pp'''
SET #Sql = #Sql + ')as value from CRS_PRODLINE'
EXEC #Sql
END
IF EXISTS (SELECT account_id FROM test_con)
BEGIN
SET #Sql = 'select dbo.make_indicator(cent,chem,co,dim,lg,pl,str,vis) + space(4) + ''no'''
SET #Sql = #Sql + ')as value from CRS_PRODLINE'
EXEC #Sql
END