Active 4 years, 8 months ago. Viewed 13k times. How to update a binary field from 0x54 to 0x46 T to F? Update dbo. Improve this question. Andriy M Harry Harry 11 1 1 gold badge 1 1 silver badge 2 2 bronze badges. There was clearly a typo in the code sample a quotation mark before the 0x46 , which I took the liberty to fix because the main issue here appears to be the wrong usage of CONVERT. Add a comment. Active Oldest Votes. Improve this answer. Yeah absolutely, I don't see why not!
The assumption by me back when I answered this was knowledge of hex codes off hand. I tried the following and it works, but then all other users have to have "face. Is there any way to update the photo column using hex value. Here are the steps:. I the script, i want to use the hex value i generated to update the photo column. How do i do that? Somthing come to my mind, but did not try that. Try to convert data to varbinary max and then update it. I think you are getting wrong image just because of Endianness.
If you are sending bytes beyond machine boundaries then you have to do reverse the bytes. Sign in. United States English. Ask a question. Quick access. Search related threads. Remove From My Forums. After adding the two event handlers, run this test case again. When deleting the category, its associated PDF is also deleted.
Updating an existing record s associated binary data provides some interesting challenges. The remainder of this tutorial delves into adding update capabilities to the brochure and picture. Step 6 explores techniques for updating the brochure information while Step 7 looks at updating the picture.
As discussed in the An Overview of Inserting, Updating, and Deleting Data tutorial, the GridView offers built-in row-level editing support that can be implemented by the tick of a checkbox if its underlying data source is appropriately configured. Currently, the CategoriesDataSource ObjectDataSource is not yet configured to include updating support, so let s add that in. Change this so that it uses the overload with five parameters.
This will cause problems with the update and delete method invocations. This will set the CommandField s ShowEditButton property to true , resulting in the addition of an Edit button and Update and Cancel buttons for the row being edited. Visit the page through a browser and click one of the row s Edit buttons. We need to create an editing interface for the BrochurePath TemplateField, one that allows the user to either:.
We also need to update the Picture ImageField s editing interface, but we'll get to this in Step 7. From the Properties window, click on the ellipses in the Items property, which will bring up the ListItem Collection Editor. Add the following three options with Value s 1, 2 and 3, respectively:. Set its Visible property to false. This RadioButtonList provides the three options for the user. The idea is that the FileUpload control will be displayed only if the last option, Upload new brochure, is selected.
To accomplish this, create an event handler for the RadioButtonList s SelectedIndexChanged event and add the following code:. Since the RadioButtonList and FileUpload controls are within a template, we have to write a bit of code to programmatically access these controls.
With this code in place, take a moment to test out the editing interface. Click on the Edit button for a row. Initially, the Use current brochure option should be selected. Changing the selected index causes a postback. If the third option is selected, the FileUpload control is displayed, otherwise it is hidden. Figure 14 shows the editing interface when the Edit button is first clicked; Figure 15 shows the interface after the Upload new brochure option is selected.
Like with the deleting workflow, we need to create event handlers for both of these events. This event handler is executed when a new category record is added from the DetailsView control we added in the previous tutorial.
Therefore, it behooves us to refactor this functionality out into separate methods. Specifically, I moved out the common functionality into two methods:. The code for these two methods follows.
In this tutorial I have updated the DetailsView s event handlers to use these new methods. Download the code associated with this tutorial to see the modifications to the DetailsView s event handlers.
Note how the RowUpdating event handler uses a series of conditional statements to perform the appropriate action based on the BrochureOptions RadioButtonList s SelectedValue property value. With this code in place, you can edit a category and have it use its current brochure, use no brochure, or upload a new one. Go ahead and try it out. Set breakpoints in the RowUpdating and RowUpdated event handlers to get a sense of the workflow.
During the editing workflow, the GridView passes a parameter to the ObjectDataSource with the parameter s name the value of the ImageField s DataImageUrlField property and the parameter s value the value entered into the textbox in the editing interface.
This behavior is suitable when the image is saved as a file on the file system and the DataImageUrlField contains the full URL of the image.
With such circumstances, the editing interface displays the image s URL in the textbox, which the user can change and have saved back to the database. Granted, this default interface doesn t allow the user to upload a new image, but it does let them change the URL of the image from the current value to another. For this tutorial, however, the ImageField s default editing interface does not suffice because the Picture binary data is being stored directly in the database and the DataImageUrlField property holds just the CategoryID.
To better understand what happens in our tutorial when a user edits a row with an ImageField, consider the following example: a user edits a row with CategoryID 10, causing the Picture ImageField to render as a textbox with the value Imagine that the user changes the value in this textbox to 50 and clicks the Update button. However, before the GridView sends this parameter and the CategoryName and Description parameters , it adds in the values from the DataKeys collection.
In short, the ImageField s editing interface has no affect on the editing workflow for this tutorial because names of the ImageField s DataImageUrlField property and the grid s DataKey value are one in the same. While the ImageField makes it easy to display an image based on database data, we don t want to provide a textbox in the editing interface.
Rather, we want to offer a FileUpload control that the end user can use to change the category s picture. Unlike the BrochurePath value, for these tutorials we ve decided to require that each category must have a picture. Therefore, we don t need to let the user indicate that there is no associated picture the user may either upload a new picture or leave the current picture as-is.
To customize the ImageField s editing interface, we need to convert it into a TemplateField. In the template you should see a TextBox remove this. Also add the text To change the category s picture, specify a new picture. To keep the category s picture the same, leave the field empty to the template, as well.
After customizing the editing interface, view your progress in a browser. When viewing a row in read-only mode, the category s image is shown as it was before, but clicking on the Edit button renders the picture column as text with a FileUpload control. Recall that the ObjectDataSource is configured to call the CategoriesBLL class s UpdateCategory method that accepts as input the binary data for the picture as a byte array.
0コメント