Have a gridview control which will show X amount of rows. I want to the user to be able to select y number of rows, but limit the maximum selected rows to a set view, such as 3. If the user tries to select a fourth row I don't want them to be able to until they unselect a row.
Anyway to do this?
Thanks
Since the GridView works with single selections, how are you allowing them to select the values in the first place, on the client or server? If on the client, you can use JavaScript to do this; simply store an array of the table rows that are selected, if the length is three, then block adding to the array until the user deselects...
Please update how you are doing it, and I can post further.
Related
I am using SQL Server. I have 2 columns Passed students and Failed Students in my database.
How to write a query which displays both these columns along with a third column which is Total Students which displays the sum of the entries in the row?
EDIT
It is not allowing me to ask another question.So,posting it here:
I have a hyperlink field in my gridview as below:
[Please refer comment for the code.For some reason it doesn't get posted here.]
Its basically a runId.When I click on this hyperlink I am redirected to a page called RunAnalysis.I want to access the value of the runId which was clicked in this page.
I was thinking of using query string but there is no event as far as I know that is fired on click of the hyperlink.
My question is how do I access the runId value in this page ? Can someone tell me if some event is fired so that I can send a query string.
Thanks.
You haven't given a lot of background information so I am assuming many things in my response.
Here is a simple aggregated result set:
SELECT SUM(Passed) AS [Passed],SUM(Failed) AS [Failed],COUNT(*) AS [TotalStudents]
FROM dbo.Students
Now if there is some grouping you want to do then you would add a GROUP BY clause like so...
I'm creating a new column because I don't know your schema:
SELECT GradeLevel, SUM(Passed) AS [Passed],SUM(Failed) AS [Failed],COUNT(*) AS [TotalStudents]
FROM dbo.Students
GROUP BY GradeLevel
ORDER BY GradeLevel
I have a form that submits parameters to a query, then opens the resulting record in another form. The problem is, whenever there is more than one record it automatically puts the first one into the from without any kind of option to choose the record I want. I have a macro set up on the search button on the first form that submits the parameters to the query and then displays it in the second form, I've tried to set up another macro in between the two, but I don't know if it's possible to set up the expression creator to check the number of rows resulting from a query. Is it possible to modify the query to create a prompt to choose which record I want? Or should I change something else?
This is the query:(automatically created by access)
SELECT CHILD.CHILD_L_NAME, CHILD.CHILD_F_NAME, CHILD.DOB, CHILD.GENDER, CHILD.DAYS_IN_CARE,
CHILD.HOURS_PER_DAY, CHILD.ENROLLMENT_DATE, CHILD.CHILD_ADDRESS, CHILD.CHILD_CITY,
CHILD.CHILD_ZIP, CHILD.CHILD_STATE, CHILD.CLASSROOM, CHILD.SNACK, CHILD.LAST_UPDATED, CHILD.CIN
FROM CHILD
WHERE (((CHILD.CHILD_L_NAME)=[Forms]![Search]![L_NAME]) AND
((CHILD.CHILD_F_NAME)=[Forms]![Search]![F_NAME])) OR
(((CHILD.CHILD_L_NAME)=[Forms]![Search]![L_NAME]) AND
((CHILD.DOB)=[Forms]![Search]![DOB])) OR
(((CHILD.DOB)=[Forms]![Search]![DOB])) OR
(((CHILD.CHILD_L_NAME)=[Forms]![Search]![L_NAME]));
If I understood well your problem and you use VBA it's quite easy to do.
You can create a reduced query based on the query you're creating with the button. This new query should include all and only the fields that allows you to discriminate beetwen the records to show in the 2nd form.
For instance it could include LastName, FirstName and classroom to select between children with same full name.
You can count the number of records of this 2nd query and if greater than 1 it means that you have more than one children to show.
So you can use this 2nd query to populate a combo-box or a listbox for selecting the record you really want to show.
When number of records is 1 you can simply skip the listbox population using an if statement on recordcount.
Next step is opening the form with the selected (or unique) record.
Bye
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Need suggestions
17 hours, 13 minutes ago|LINK
I have an insert data page, having a drop down on the page items are filling from SQL Data Source (using code behind)
I need to apply some filter to chop out certain values from Drop Down (user will select some radio buttons and then
apply the filter, when filter applies, it will remove the unwanted items from drop down)
Now I dont know what is best procedure, I have done:
1) Using AJAX update panel, so when the user clicks on Apply, I am re-generating query and re-binding the drop down list)
so it involves server round trip, every time user clicks on apply button.
The best thing about this is, if user wants to insert records one by one, then user does not have to apply filter agian and again
(once applied it will only show the filtered values after each record insertion)
2) Using client side javascript i have achieved the same but big problem here is that
once a record is inserted, the page will refresh, and thus the drop down will show all the UN-Filtered values again
I need suggestions on which techinque I should follow in this regard, plz help
Using ajax is the best option, but in sql you create a stored procedure, so that it might reduce the time of regenerating query.
I have a list of values in a SQL Table which are used to popluate a DropDownList, having a unique Integer as the value of each item and a String as the visible text (via SqlDataSource). There is also a third field in the database which is a flag to indicate whether the list item is active or not (inactive items are not shown in the DropDownList)
Selections made in the dropdown are stored in the database as their integer value (as part of a dataset making up the overall record), not the text value.
Over time, the items in the DropDownList may be removed by marking the items as inactive. However, there is still a need to open old records which may have had a now-inactive item as part of it's data...
My question is, what's the best way to ensure that the missing value included in the dropdown for the old record?
The two methods that spring to mind are to either:
Populate DropDownList with only the currently active items and, when loading a record, catch when the app tries to select a value that doesn't exist, go back to the db to see what it should be (the text value) and manually add it into the dropdown.
or...
Populate DropDownList with all list items (both active and inactive), load the record and then programatically remove all the inactive items (execpt for any that are now selected).
Neither of these seem particularly efficient, so I was wondering whether there is a best practice for this kind of thing?
there are so many optimum ways to do that sort of things, i am defining here a couple of them, use any of following if your Drop down list items count is less than 200 , lets say drop down list is of Products
1)
i) Load all Products records in drop down list and hide the inactive ones by setting visible=false
i) When you load a user record than look for its drop down list value if its visible than select it and enjoy, if its not visible than make it visible by setting its property visible=true and select it and also set its index or id in a flag to change its visibility(visible=false) again after your/users required operation performed.
2)
i) load only active Product records in drop down list ii) while loading a user record also load its product details(name, id, inactive_status) using Joins in sql.
iii) check in that user record if item is inactive then add its record in drop down list as you have all its details now with user details record else just select it.
IMPORTANT NOTE: if you drop down list has items in millions than use ADVANCE SEARCH techniques
The first thing I would do is question your business logic - should you be able to make an item inactive if it is being used as a foreign key in an active row elsewhere? If you make it inactive should it not remove all foreign keys as well?
To answer your question though I would go with a variation on the second idea but filtering in the page like that is probably slower than doing directly with SQL so I guess you have something like this at the moment to populate the dropdown
SELECT * FROM Table WHERE Active = 1
You should already have your record and the foreign key value so I would change it to this
SELECT * FROM Table WHERE Active = 1 OR PrimaryKey = [YourForeignKey]
Then you will always have the selected item but should also be fairly efficient.
How Can I find all the rows that has been changed in gridview. I can not use Ajax in any form
First get the contents of your grid before it was changed (such as caching the results of the original gridview datasource binding). Then go through the dataset/datatable/however you want to store it, and compare the contents with the current rows of the gridview.
There's no real efficient way to do this, no method like GridView.GetAllChangedRows(). So, what you might do instead is keep a behind the scenes List that you add to each time a row is modified (use the RowUpdated method), then clear this list when needed.
It depends upon how many columns you want to edit in a row.
If you have only one editable column in a row then you can associate a javascript method with that control which you want to modify and in that method you can get a rowid which you can save in another hidden field and in server side you can get all rows whose ids are stored in hidden field.
If you have whole row editable in that case the best approach I think you should save the original data source somewhere and also set a javascript method with rowclick event to get rowid which user selects. Then when user clicks on submit button get all rows whose row ids are stored in hidden field then compare those with same rowid in datasource. This is the best approach from my point of you.
Let me give you an example, suppose there are 1000 rows in a grid and user clicks on only 180 rows. In that case we will compare only 180 rows and wont compare rest of the rows.
Please let me know if somebody has better idea then this.