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Reading Blobs from SQL and using it in an Image control of a webfo

Please This is queit a task av been trying to solve. Could anyone please tell
me how to read a blob from an SQL using a dataset and stuffing this image
into the Image control of a webform.
Any suggetion that would help would be highly appreciated.
--
Iyke
Mar 19 '06 #1
9 1846
This is an example of the Page_Load event of a page GetImage.aspx:

protected void Page_Load(objec t sender, System.EventArg s e)
{
// get image id
string imageId = this.Request.Pa rams["id"];

System.Data.Sql Types.SqlBinary image; // image from database
string sql = String.Format ("SELECT photo FROM customers WHERE
customer_id = {0}", imageId);

// get image from database
SqlConnection conn = new SqlConnection (myConnectionSt ring);
SqlCommand com = new qlCommand (sql, conn);
conn.Open();
try
{
SqlDataReader reader = dba.RunSelect (sql);
reader.Read ();
image = reader.GetSqlBi nary(0);
reader.Close ();
}
finally
{
conn.Close ();
}

if (!image.IsNull && image.Value.Len gth != 0)
{
// stream image down to client
this.Response.C ontentType = "image/gif";
this.Response.B inaryWrite (image.Value);
}
}

You would use this page as an url for your image control in format
"GetImage.aspx? id=xx".

Eliyahu

"JuniorProgramm er" <tr****@discuss ions.microsoft. com> wrote in message
news:A9******** *************** ***********@mic rosoft.com...
Please This is queit a task av been trying to solve. Could anyone please
tell
me how to read a blob from an SQL using a dataset and stuffing this image
into the Image control of a webform.
Any suggetion that would help would be highly appreciated.
--
Iyke

Mar 19 '06 #2
On Sun, 19 Mar 2006 02:39:13 -0800, JuniorProgramme r wrote:
Any suggetion that would help would be highly appreciated.


I suggest NOT using the database to store images, unless they're fairly
small ones. Instead, store the image on the disk, and store a filename
pointer to it in the database. This will make your database smaller, less
prone to fragmentation, and reduce the bandwidth being consumed by record
requests.

In my opinion, storing images in databases takes far more resources than
storing them in the file system.
Mar 19 '06 #3
Often, security considerations make using database mandatory.

Eliyahu

"Erik Funkenbusch" <er**@despam-funkenbusch.com > wrote in message
news:6t******** *******@funkenb usch.com...
On Sun, 19 Mar 2006 02:39:13 -0800, JuniorProgramme r wrote:
Any suggetion that would help would be highly appreciated.


I suggest NOT using the database to store images, unless they're fairly
small ones. Instead, store the image on the disk, and store a filename
pointer to it in the database. This will make your database smaller, less
prone to fragmentation, and reduce the bandwidth being consumed by record
requests.

In my opinion, storing images in databases takes far more resources than
storing them in the file system.

Mar 19 '06 #4
On Sun, 19 Mar 2006 17:21:11 +0200, Eliyahu Goldin wrote:
Often, security considerations make using database mandatory.


That doesn't make any sense. Any security consideration you can put in
place via SQL can be put in place using file permissions.
Mar 19 '06 #5
In SQL Server you can setup security rights for sql logons and roles. File
permissions can be granted to windows accounts, not to sql ones.

Eliyahu

"Erik Funkenbusch" <er**@despam-funkenbusch.com > wrote in message
news:f8******** *******@funkenb usch.com...
On Sun, 19 Mar 2006 17:21:11 +0200, Eliyahu Goldin wrote:
Often, security considerations make using database mandatory.


That doesn't make any sense. Any security consideration you can put in
place via SQL can be put in place using file permissions.

Mar 19 '06 #6
On Sun, 19 Mar 2006 18:05:20 +0200, Eliyahu Goldin wrote:
In SQL Server you can setup security rights for sql logons and roles. File
permissions can be granted to windows accounts, not to sql ones.


Windows also has security rights and roles. Again, anything you can define
in SQL can be defined in Windows as well. If you're stuck on using SQL for
your security, it's pathetically easy to validate security through SQL to
access files on the hard disk.

Security is not a valid reason in my opinion.
Mar 19 '06 #7

"Eliyahu Goldin" <re************ *@monarchmed.co m> wrote:
Often, security considerations make using database mandatory.


Well, even more often the database could be accessed across domains, and
through different applications (or application layers) that does not allow
the use of a std. filesystem access.
- in that case the Database seems the more flexible choice.

R-)
Mar 19 '06 #8
Security considerations notwithstanding ,
here is an alternative method for reading and displaying images as you
describe without the need for an external handler (e.g., get them directly
out of the same DataSet your other data is in):

http://www.eggheadcafe.com/articles/20050911.asp

Peter
--
Co-founder, Eggheadcafe.com developer portal:
http://www.eggheadcafe.com
UnBlog:
http://petesbloggerama.blogspot.com


"JuniorProgramm er" wrote:
Please This is queit a task av been trying to solve. Could anyone please tell
me how to read a blob from an SQL using a dataset and stuffing this image
into the Image control of a webform.
Any suggetion that would help would be highly appreciated.
--
Iyke

Mar 19 '06 #9
I want to thank you all for ur replies. Every contribution made good sence,
even broadens my idea of the issue.

Thank you very much one and all.
Mar 20 '06 #10

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