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It's always important for your website visitors to see fresh content. One simple way to do this to have a set of images
display on a page that change each time the page is visited or refreshed. Nearly any type of website web site could benefit from this type of dynamic content. You've probably seen
animated .gif images before but those can be large files which will impact page-load performance.
This website is using this very feature in the ASP.NET Master Page to rotate the scenic picture in the upper right corner of the page.
Our site is only rotating one picture at a time. However we've designed other sites to use this feature to show multiple pictures. This Lesson has the following steps:
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Step 1. SQL Server table and stored procedure
First we create a table called "gallery_images". Open SQL Server and open a new query window in your database. Cut and
paste the following SQL statement below to create a table called "gallerly_images". This table will store our data about the images that we want to display. The "Img" field will store
the url to the image on the web site. For example "/images/rotate/rotate1.jpg"
CREATE TABLE [dbo].[Gallery_Images](
[ImageID] [int] IDENTITY(1,1) NOT NULL,
[Img] [varchar](50) NULL,
[imgH] [int] NULL,
[imgW] [int] NULL,
[Dttm] [datetime] NULL,
CONSTRAINT [PK_Gallery_Images] PRIMARY KEY CLUSTERED
(
[ImageID] ASC
)WITH (PAD_INDEX = OFF,
STATISTICS_NORECOMPUTE
= OFF, IGNORE_DUP_KEY = OFF,
ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
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Now manually upload some images to a folder on your site. In our example we'll be using /images/rotate/ and then enter the urls to the images into the gallery_images table we created. Be sure to add 5-6 images.
After adding some data your table should look similar to this with different image names naturally.
Next keeping an eye on security and performance we'll create a SQL Server stored procedure to query the
images from the table we just created. Be sure to assign execute permissions for this stored procedure to the sql login that your web site uses to query the database.
Create PROCEDURE [dbo].[sp_images_random]
AS
select top 1 img as 'url' from gallery_images
order by newid() desc
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Being good programmers we always test our code on the database before hooking it into a web page so manually execute the store procedure we just created in a query window
Next Lesson
In Step 2. ASP.NET Image Control we'll setup an ASP.NET page using the ASP.NET Image Control to store the results of our query.
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Search Engine Submission
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They Said It Best |
Indeed, it would not be an exaggeration to describe the history of the computer industry for the past decade as a massive effort to keep up with Apple.
Byte, December 1994
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