How do I use a path stored in table with OPENROWSET?

Question

I have just recently began using OPENROWSET to insert images into a table. Previously, I would specify the path to each image (1 image = 1 INSERT statement), and use PHP to generate the image's binary string:

INSERT INTO nopCommerce..Picture (PictureBinary, MimeType, SeoFilename, AltAttribute, TitleAttribute, IsNew)
VALUES (
    (
        SELECT *
        FROM OPENROWSET(BULK '" . $this->image['path'] . "', SINGLE_BLOB) AS Binary
    ),
    '" . $this->image['mime_type'] . "',
    '" . $this->image['seo_filename'] . "',
    '" . $this->image['alt'] . "',
    '',
    0
)

However, I am trying to insert all images with a single query. So, I have began storing the path to each image into a table, and now I need to insert each one as I did before (just using the table's path field instead of a PHP string). But, when I attempt the following:

INSERT INTO nopCommerce..Picture (PictureBinary, MimeType, SeoFilename, AltAttribute, TitleAttribute, IsNew)
SELECT
    (
        SELECT *
        FROM OPENROWSET(BULK ImagePath, SINGLE_BLOB) AS Binary
    ),
    MimeType,
    Name,
    Alt,
    '',
    0
FROM nopRMS..Product_Image_Mappings

I receive the following error:

Msg 102, Level 15, State 1, Line 5
Incorrect syntax near 'ImagePath'.

So, I tried adding quotes around the column's name (to no avail):

INSERT INTO nopCommerce..Picture (PictureBinary, MimeType, SeoFilename, AltAttribute, TitleAttribute, IsNew)
SELECT
    (
        SELECT *
        FROM OPENROWSET(BULK 'ImagePath', SINGLE_BLOB) AS Binary
    ),
    MimeType,
    Name,
    Alt,
    '',
    0
FROM nopRMS..Product_Image_Mappings

Msg 4860, Level 16, State 1, Line 1
Cannot bulk load. The file "ImagePath" does not exist.

There has to be a way to accomplish this, I just cannot find the proper syntax online anywhere. Does anyone know how to tell SQL Server to get the path (string) from dbo.Product_Image_Mappings.ImagePath?

UPDATE
I forgot to give you an example of a value that dbo.Product_Image_Mappings.ImagePath would return. It's paths like \\DEREK\WebImages\1\ca-82300.jpg...

UPDATE
It appears that Eirikur Eiriksson has provided a solution in this thread, but this looks like an overly-complicated method of achieving the same end...

UPDATE (Attempt Using Eirikur Eiriksson's Method)

DECLARE @SQL_STR NVARCHAR(MAX) = N'';

SELECT @SQL_STR = STUFF(
    (
        SELECT 
            N'
            UNION ALL
            SELECT '
            + N'(SELECT X.BulkColumn FROM OPENROWSET(BULK '
            + NCHAR(39) + im.ImagePath + NCHAR(39)
            + N', SINGLE_BLOB) AS X) AS PictureBinary,'
            + NCHAR(39) + im.MimeType + NCHAR(39)
            + N' AS MimeType,'
            + NCHAR(39) + im.Name + NCHAR(39)
            + N' AS SeoFilename,'
            + NCHAR(39) + REPLACE(im.Alt, '''', '''''') + NCHAR(39)
            + N' AS AltAttribute,'
            + N'NULL AS TitleAttribute,'
            + N'0 AS IsNew'
        FROM nopRMS..Product_Image_Mappings im
        FOR XML PATH(''), TYPE
    ).value('.[1]','NVARCHAR(MAX)'),1,12,N''
)

INSERT INTO nopCommerce..Picture (PictureBinary, MimeType, SeoFilename, AltAttribute, TitleAttribute, IsNew)
EXEC (@SQL_STR);

This kinda worked, but it only inserted 42 rows (out of 7200+)... I need this to be 100% accurate :( I admit though, I may need to change something about this query, but I don't know anything about it (aside from the basic INSERT, SELECT, etc.)

Answer 1

Maybe don't use OPENROWSET? What you are wanting can be handled in a much simpler and cleaner manner using SQLCLR. You can create a Scalar UDF to just read the contents of a file and return that as a VARBINARY(MAX). Then it will fit in nicely to your existing query. For example:

INSERT INTO nopCommerce.dbo.Picture (PictureBinary, MimeType, SeoFilename, 
                      AltAttribute, TitleAttribute, IsNew)
SELECT
    dbo.GetBinaryFile([ImagePath]) AS [PictureBinary],
    MimeType,
    Name,
    Alt,
    '',
    0
FROM nopRMS.dbo.Product_Image_Mappings;

And how much code does it take for dbo.GetBinaryFile()? Here it is:

using System;
using System.Data.SqlTypes;
using System.IO;
using Microsoft.SqlServer.Server;

[return:SqlFacet(MaxSize = -1)]
[SqlFunction(IsDeterministic = false, IsPrecise = true)]
public static SqlBytes GetBinaryFile([SqlFacet(MaxSize = 1000)] SqlString FilePath)
{
    if (FilePath.Value.Trim().Equals(String.Empty))
    {
        return SqlBytes.Null;
    }

    return new SqlBytes(File.ReadAllBytes(FilePath.Value));
}

And the T-SQL wrapper object is the following (please note the WITH RETURNS NULL ON NULL INPUT line as it skips execution if NULL is passed in, hence no need to check for FilePath.IsNull in the C# code :-)

CREATE FUNCTION [dbo].[GetBinaryFile](@FilePath NVARCHAR(1000))
RETURNS VARBINARY(MAX)
WITH RETURNS NULL ON NULL INPUT
AS
 EXTERNAL NAME [CSVParser].[CSVUtils].[GetBinaryFile];

The Assembly will need to be marked as WITH PERMISSION_SET = EXTERNAL_ACCESS. Many people go the easy route of setting the database property of TRUSTWORTHY to ON in order to accomplish this, but that is a security risk and isn't even necessary. Just do the following and you can set the Assembly to EXTERNAL_ACCESS while keeping TRUSTWORTHY set to OFF:

1. Sign the Assembly.
2. Create an Asymmetric Key in master from that DLL.
3. Create a Login (also in master) from that Asymmetric Key.
4. Grant the new Login the EXTERNAL ACCESS ASSEMBLY permission.

You can find detailed instructions on how to do this in Visual Studio / SSDT (SQL Server Data Tools) in the following article that I wrote: Stairway to SQLCLR Level 7: Development and Security (that site does require free registration in order to view the content).

Also, for anyone that does not want to bother with creating / deploying the Assembly, a similar function is available (though not for free) in the Full version of the SQL# library (which I created, and while many functions are free, the File_* file system functions are only in the Full version).