Stored procedure that exports data into csv files

Question

I have a fun script:

DECLARE @StartDT DATE
DECLARE @MinDOS DATE
DECLARE @TableName VARCHAR(50)
SET @TableName = 'ViewAccountDetail'
SELECT @MinDOS = MIN(dos) FROM accn_demographics
SELECT @StartDT = 
    CAST(CAST(datepart(YYYY,@MinDOS) AS varchar) + '-' + CAST(datepart(mm,@MinDOS) AS varchar) + '-' + CAST('01' AS varchar) AS DATETIME)
DECLARE @FileLocation VARCHAR(50)

WHILE @StartDT < '20110901'
BEGIN
    SET @FileLocation='C:\test\'+@TableName+cast(@StartDT as varchar)+'.csv'
    EXEC BCP_Text_File @TableName, @FileLocation    
    SET @StartDT = DATEADD(MONTH,1,@StartDT)
END

It is supposed to do is export data into csv files. The names of the files should be:

C:\test\ViewAccountDetail2011-01-01.csv
C:\test\ViewAccountDetail2011-02-01.csv
C:\test\ViewAccountDetail2011-03-01.csv
C:\test\ViewAccountDetail2011-04-01.csv
C:\test\ViewAccountDetail2011-05-01.csv
C:\test\ViewAccountDetail2011-06-01.csv
C:\test\ViewAccountDetail2011-07-01.csv
C:\test\ViewAccountDetail2011-08-01.csv

but it stores all the data into the same one:

C:\test\ViewAccountDetail2011-01-01.csv

i did a print @FileLocation and confirmed that it correctly updates this variable.

is there any apparent, OBVIOUS thing that i am missing here?

FYI this line:

EXEC BCP_Text_File @TableName, @FileLocation

calls this procedure:

  ALTER PROCEDURE [dbo].[BCP_Text_File]
    @table    NVARCHAR(255),  
    @filename VARCHAR(100)  
AS
BEGIN
  SET NOCOUNT ON;

  IF OBJECT_ID(@table) IS NOT NULL
  BEGIN
    DECLARE 
        @sql NVARCHAR(MAX), 
        @cols NVARCHAR(MAX) = N'';

    SELECT @cols += ',' + name
      FROM sys.columns
      WHERE [object_id] = OBJECT_ID(@table)
      ORDER BY column_id;

    SELECT @cols = STUFF(@cols, 1, 1, '');

    SET @sql = N'EXEC master..xp_cmdshell ''bcp "SELECT ''''' 
        + REPLACE(@cols, ',', ''''',''''') + ''''' UNION ALL SELECT ' 
        + 'RTRIM(' + REPLACE(@cols, ',', '),RTRIM(') + ') FROM ' 
        + DB_NAME() + '..' + @table + '" queryout "' + @filename + '" -c -T''';  

    EXEC sp_executesql @sql;
  END
  ELSE
  BEGIN
    SELECT 'The table '+@table+' does not exist in the database';
  END
END

GO

thank you so much for your help and guidance!!

Answer 1

Seems to work fine for me. I have a few suggestions:

(1) stop doing all that string concatenation to build a date. You can do the same thing much easier as in:

SELECT @StartDT = DATEADD(MONTH, DATEDIFF(MONTH, '19000101', @MinDOS), '19000101');

(2) stop declaring varchar without length. And to ensure the right output, I prefer convert:

SET @FileLocation = 'C:\test\' + @TableName
   + CONVERT(CHAR(10), @StartDT, 120) + '.csv';

(3) instead of "debugging" the code by running the stored procedure and inspecting the output in the folder, why not sanity-check your input first? Also, why use two variables for the date?

DECLARE 
   @StartDT DATE, 
   @TableName NVARCHAR(50), 
   @FileLocation VARCHAR(255);

SET @TableName = N'ViewAccountDetail';

SELECT @StartDT = DATEADD(MONTH, DATEDIFF(MONTH, '19000101', MIN(dos)), '19000101')
   FROM dbo.accn_demographics;

   PRINT @StartDT;
-- ^^^^^ debugging 101 - what month do we think we're starting at?

WHILE @StartDT < '20110901'
BEGIN
    SET @FileLocation = 'C:\test\' + @TableName
      + CONVERT(CHAR(10), @StartDT, 120) + '.csv';

      PRINT @FileLocation;
    --^^^^^ again, debugging 101 - what does the filename currently look like?

    --EXEC BCP_Text_File @TableName, @FileLocation    
    SET @StartDT = DATEADD(MONTH, 1, @StartDT);
END