Putting Declare Variable in String (of a Bulk Insert) - tsql

Question

trying to get an ETL package going which requires bulk inserting a bunch of .csv files off of a drive. Instead of manually having to scroll through the code and change the file path name for each insert (it increments with each month), would just like to declare the variable at the top.
Eg.
DECLARE #Month NVARCHAR(255)
SET #Month = 'November'
DECLARE #Year NVARCHAR(255)
SET #Year = '2019'
BULK INSERT #MonthlyMetrics
FROM '\\SomeServer\SomeFolder\Metrics_#Month_#Year.csv'
WITH
(
FIELDTERMINATOR = ','
, ROWTERMINATOR = '0x0a'
, FIRSTROW = 3
)
GO
There's a dozen of inserts like this where the only part of the file name that changes is the month. i.e. Metrics_November_2019.csv is that actual file name. Since the FROM is a string, not sure how to get the declared variable in there.

Answer 1

You can try using a dynamic SQL to load the data, only you will need to enable xp_cmdshell like this:
This turns on advanced options and is needed to configure xp_cmdshell
sp_configure 'show advanced options', '1';
RECONFIGURE
This enables xp_cmdshell
sp_configure 'xp_cmdshell', '1'
RECONFIGURE
After that you can load the data in your temp table:
DECLARE #dir varchar(300)
DECLARE #files table (FileName varchar(800));
DECLARE #filesCmd varchar(500);
DECLARE #filename varchar(100);
DECLARE #cmd_BulkInsert nvarchar(max);
SET #dir = '\\SomeServer\SomeFolder';
SET #filesCmd = 'DIR /b ' + #dir + ' | findstr csv';
INSERT INTO #files EXECUTE xp_cmdshell #filesCmd;
BEGIN TRY
DECLARE C_TABLE CURSOR LOCAL FORWARD_ONLY READ_ONLY STATIC FOR
SELECT FileName FROM #files WHERE NOT FileName IS NULL;
OPEN C_TABLE;
FETCH NEXT FROM C_TABLE INTO #filename;
WHILE ##FETCH_STATUS = 0
BEGIN
SET #cmd_BulkInsert = N'
BULK INSERT #MonthlyMetrics
FROM '''+#dir+'\'+#filename+'''
WITH
(
FIELDTERMINATOR = '',''
,ROWTERMINATOR = ''0x0a''
,FIRSTROW = 3
)'
EXECUTE sp_executesql #cmd_BulkInsert;
FETCH NEXT FROM C_TABLE INTO #filename;
END
END TRY
BEGIN CATCH
SELECT
GETDATE()
,ERROR_LINE()
,ERROR_MESSAGE()
,ERROR_NUMBER()
,ERROR_STATE()
,ERROR_SEVERITY()
,#cmd_BulkInsert
END CATCH