Excel data filtration using oledb from huge excel files size approx (200mb) using c# (ADO)

Question

hi,
My ado application requires to read data from one xlsx file(Approx 10-20MB min) and then process the data row by row and compare with
another xlsx file( approx size 250 MB min) containing over 1000000 rows with 63 columns (work like database).
when i try to read the database file (250 MB) and run the oledb data queries on it, it's working so strange, its only give the first matched data from the database file. but if i opened that xlsx database file in office excel and then run my application
its return all matched data from the database file without changing any code.
i already checked my dataquery its working fine in server Explorer and returns the complete result.
this process also very time consuming ,
i already tried openxml sax mathod to resolve the performance issue as well, but its not worked too. even it takes more time compare to oledb to read the excel.
i also have two another issues in my application,
1. sometime oledb returns an exception 'System resource exceeded' and
2. some time return 'internal ole automation error' .
i also tried google to resolve these issue but i didn't find any solution for my problem.
is there any solution to resolve these issues?  please help me. any suggestion appreciated but please remember one thing i can't change any xlsx table format because i don't have rights, these xlsx files automatically generated by another tools by our
sourcing partners.
thanks.

Answer 1

Please see this.
http://www.sqlis.com/post/Looping-over-files-with-the-Foreach-Loop.aspx
Or, if you don't have SSIS, do Bulk Insert by looping through the files.  Let's say the files have something in common, like a date in the name of the file.  Simply run this SQL Server script . . . 
DECLARE @intFlag
INT
SET @intFlag
= 1
WHILE (@intFlag
<=48)
BEGIN
PRINT @intFlag
declare @fullpath1
varchar(1000)
select @fullpath1
= '''\\ftp\your_path\'
+ convert(varchar,
getdate()- @intFlag
, 112)
+ '_your_file.txt'''
declare @cmd1
nvarchar(1000)
select @cmd1
= 'bulk insert [dbo].[your_table] from '
+ @fullpath1 +
' with (FIELDTERMINATOR = ''\t'', FIRSTROW = 2, ROWTERMINATOR=''0x0a'')'
exec (@cmd1)
SET @intFlag
= @intFlag + 1
END
GO
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