dynamic sql not parsing correctly - sql-server

Question

I am writing a dynamic sql statement that will check if the index exist and drop it. Getting compile error Could somebody tell what the problem is . I double checked the ticks but cant understand
declare #startyear int = 2000
declare #startQuarter int = 1
declare #sql nvarchar(max)
declare #tableName varchar(50)
if #startYear is null
set #startYear = 2000;
set #startQuarter = 1;
while #startYear <= year(getdate())
begin
set #startQuarter = 1;
while #startQuarter < 5
begin
set #tableName = 'FinData' + cast(#startYear as varchar) + '_' + cast(#startQuarter as varchar);
set #sql = 'IF EXISTS(SELECT * FROM sys.indexes WHERE object_id = object_id(' + #tableName + ') AND NAME = ' + '.idx_' + #tableName
drop index' + #tableName + '.idx_' + #tableName
print #sql
set #startQuarter += 1
end
set #startYear += 1;
end

Answer 1

Two issues: this isn't adding anything before the .idx, it's just concatenating the strings together:
') AND NAME = ' + '.idx_'
And then there's a single-quote missing at the end of that line. It looks like your indexes are named after the table's name: tablename.idx_tablename, so try this:
DECLARE #startyear INT = 2000;
DECLARE #startQuarter INT = 1;
DECLARE #sql NVARCHAR(MAX);
DECLARE #tableName VARCHAR(50);
IF #startyear IS NULL
SET #startyear = 2000;
SET #startQuarter = 1;
WHILE #startyear <= YEAR(GETDATE())
BEGIN
SET #startQuarter = 1;
WHILE #startQuarter < 5
BEGIN
SET #tableName = 'FinData' + CAST(#startyear AS VARCHAR) + '_'
+ CAST(#startQuarter AS VARCHAR);
SET #sql = 'IF EXISTS(SELECT * FROM sys.indexes WHERE object_id = object_id('
+ #tableName + ') AND NAME = ' + #tableName + '.idx_' + #tableName + '
drop index' + #tableName + '.idx_' + #tableName;
PRINT #sql;
SET #startQuarter += 1;
END;
SET #startyear += 1;
END;

Answer 2

This does not answer your question, however, it is worth mentioning that if you want to do this without looping, you could create a virtual numbers table to join with.
;WITH
A AS(SELECT 0 AS Q UNION ALL SELECT 0),
B AS(SELECT 0 AS Q FROM A AS A CROSS JOIN A AS B),
C AS(SELECT 0 AS Q FROM B AS A CROSS JOIN B AS B),
D AS(SELECT 0 AS Q FROM C AS A CROSS JOIN C AS B),
E AS(SELECT 0 AS Q FROM D AS A CROSS JOIN D AS B),
F AS(SELECT 0 AS Q FROM E AS A CROSS JOIN E AS B),
Numbers AS(SELECT ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS Number FROM F)
SELECT
Y.Number,Q.Number
FROM
Numbers Y
INNER JOIN Numbers Q ON Q.Number BETWEEN 1 AND 4
WHERE
Y.Number BETWEEN 2000 AND YEAR(GETDATE())
ORDER BY
Y.Number