DataSource Controls :: Entity Query To Validate Ntry Not Already In A Table
Jun 16, 2010
I have a button click event that adds a record to a table based on the userid and threadid the user is viewing. I am a bit new to entity so I am stumbling around. I have to where conditions
ThreadID == threadid
UserId == userIdPosts
I have this query but do not know how to execute it and if I have it as is I get this in the yellow screen of death Both the theadid and userIdPosts have data in them.
Line 90: // find is user has already tracked this thread.
Line 91: var query = context.TrackLists.First(t => t.ThreadID == threadid);
Line 92: context.TrackLists.First(t => t.UserId == userIdPosts);
Dim MediaQuery = From m In dB.DOWNLOADS _Where m.ID = id _Select
which returns a record from the database. One of the fields in the record is a FK to another table. I need to read this value to be able to set a dropdown based on the ID but I can't work out how to access it. For a standard record I can just do the following txtTitle.Text = MediaQuery.FirstOrDefault().TITLE
However with the foreign key it doesn't work like that. I've tried drpGroup.SelectedIndex = MediaQuery.FirstOrDefault().DOWNLOAD_GROUPS.ID where DOWNLOAD_GROUPS is the FK field but it returns Object reference not set to an instance of an object. If you're simply wanting to read some values from a single db record in the entitiy framework and one is a foreign key how should I go about getting the value?
I use LINQ to SQL and I added some meta data to my entity objects.
But how can I validate this entity object in ASP.NET 3.5 Forms ? I find a lot information for validating this objects in MVC, but that is not what I want of course :) .
Need to figure out the correct way to do a simple SUM function in Linq, but also manipulate one of the feilds coming back by doing a Substring on it, here is the original SQL query:
I have a user control, named productslist.ascx. On pruductslist.ascx, I am using Entity Datasource and a QUERY EXTENDER and LISTview. I have a page Defualt.aspx. On Defualt.aspx, I have a TEXTBOX with a SUBMIT button for searching the site. Everthing works fine so far, AS LONG as the results of the Search is posted back to Default.aspx. What I want is for the results of the search to be posted on a different page. So I created a new page, Results.aspx and set the postback url to it.
What I want is that when a user clicks the Submit button, after entering a search string, the text the entered is used to execute the query on Productslist.ascx and the results displayed on RESULTS.ASPX. Again, everything works fine as long as the results are posted on same page hosting the usercontrol, BUT I want the postback url to be a different page. I am coding in VB and VS 2010.
I have three table like above, table C is mapping table which has foreign key of Table A and B.How can i select and insert data in Table C using Entity Frame Work?
ItemNo refno Process Name Qty 001 1 A John 50 001 2 A Jon 150 002 3 B Kalis 100 003 4 A Bob 300 Second Table ItemNo Newrefno Process Name Qty 001 001 ZZ peter 50 001 001/a ZkZ Joe 70 002 002 Ab Ray 100 Result Set 001 A John 200 001/a ZZ ZkZ peter joe 50 70 002 B Kalis 100 002 Ab Null Ray Null 100 Null 003 A Bob 300 null null null null null null null
Here first row of the result set explanation:
up to this 001 A John 200 based on first table sum...
and 001/a zz ZkZ peter joe 50 70
here 001/a newrefno of 001 so i need to show all the ItemNo 001 record in one row like the above resultset.
<asp:sqldatasource id="SqlDataSourceX" runat="server" connectionstring="<%$ ConnectionStrings:MyConn%>" providername="System.Data.SqlClient" selectcommand="SELECT ItemNum, MIN(DateAdded) as [DateAdded] FROM Items WITH (NOLOCK) WHERE [DateAdded] between @DateFrom AND @DateTo
[Code]....
When I call select in codebehind, after 30sec it throws timeout expired SqlException:
[Code]....
again , this select took up to 3 sec to be executed. In application I tried to use SqlConnection and SqlTableAdapter instead of SqlDataSource, with the same query, and again it took up to 3 sec.
If I choose tighter interval (e.g '2011-01-20 00:00:00' - '2011-01-21 00:00:00') , there is no timeout exception, so I know that sqldatasource select is executed correctly. So the conclusion is that sql server is not using index while executing query sent from sqldatasource, but is using index whenever else. I have also checked the index statistics on sql server and it is like that. In profiler i can see slight difference between this two cases. As for SqlDataSource, in events table, in first column "EventClass" after 30 sec, there is this: "RPC:Completed" and application throws timeout. If i use SqlConnection and SqlTableAdapter then at the same place there is this: "SQL:BatchStarting" and "SQL:BatchCompleted" and application does not throws timeout(the index has been used).
what is so special on SqlDataSource connection, that Sql Server performs differently compared to other types of connections?
I am trying to update my table ARTICLES and it has a field COUNTER, Everytime a user enter this ARTICLES, the page_load event runs a LINQ to SQL query taking the QueryString as parameter, increasing the COUNTER field in 1.
I have a table that contains image data type and has more than 20,000 records.I want to change its file group to the new file group. I tried to change it using table designer, but everytime I wanted to save it, it occured an error with this message:
[Code]....
Does anyone know how to change file group using Alter Table query? I'm using SQL Server 2005.
I have tried to query a table with an xml column by using XQuery and I can't get the Select to work.
All my knowledge/understanding of the subject comes from this MSDN article:
[URL]
so I am probably overlooking something minor:
I tried this query Select col1, Phone.Query('element CellPhone {I am not sure about what goes here} I tried {data('Phone/cellPhone} from aTable Where Phone.Exist('/Phone/cellPhone/text()[contains.,"412-8977"]') = 1 This syntax is definitely not fun.
I'm implementing a BLL layer and have a few questions. First, in my DAL, there is a contacts table, the select method is a sql query against a sql server 2000 database. The preview data returns everyting as expected. The query is
[Code]....
The BLL method is built like so
[Code]....
When using the BLL method to a gridview, the results of the subquery are not displayed. There are also other methods, each having a different where clause for ContactRole_ID and each is having the same issue of not displaying the subquery reult in the gridview. No error, but no data is displayed for the subquery either. Here is the templatefield of the gridview
[Code]....
Another item that is causing an error is in trying to update a record. Here is the DAL update method
[Code]....
And the BLL update method
[Code]....
The error says i have extra parameters, but have no clue where the extra parameters are being picked up. The error isObjectDataSource 'odsContacts' could not find a non-generic method 'UpdateContact' that has parameters: _ContactID, _Active, _ContactName, _Office, _VirtualOffice, _Pager, _Fax, _Home, _Cellular, _Email, _ContactRole_ID, Active, ContactRole_ID, ContactName, Office, Email, VirtualOffice, Pager, FAX, Home, Cellular.And the objectdatasource
Let's say we have a entity to add - an Invoice with multiple Lines
public class Lines { public string ObjectName; public string Color; } public class Invoice { public string DocumentID; public DateTime InvoiceDate; public List<Lines> lines; public string Observation; }
The Lines is valid if and only if it has ObjectName and Color
Now, when in AddMode , the requirements are to show enter a new Invoice with 10 Lines by default .
This was easy (binding to an object that contains list, right?) - but in validation mode, the ModelState.IsValid is validating all my 10 lines - regardless if the user have been entered only 2 lines.
I have tried to remove the empty lines by writing a Binder for Invoice, inheriting from DefaultModelBinder and removing the empty lines ( those for ObjectName AND Color both nulls or empty ) .But, no matter what overriding method (CreateModel , BindModel ) I have used , no success. The binding model occurs first.
I have tried to do ModelState.Clear() and ValidateModel(invoice) in the controller. But ValidateModel is not validating "sub-properties of complex properties" - see comments from
[URL]
If you know how to either :
a) re-validate all properties (including for complex object)
b) modifying the model before ModelState grab errors
c) ?
(I can not debug with MVC2 source code - but this is another post...)
1. I have a GridView on my page and it uses sqldatasource with parameterized query. What I want to do is, on page load (where nothing has been selected so no parameter supplied), I want it to query everything (something like SELECT * FROM [this_table]) but since my SelectCommand is something like
SELECT * FROM [this_table] WHERE [this_column] = @someParameters AND [that_column] = @someParameters.
Can I play around with default value to achieve something like that but how ? Now, when the page loads, it doesn't show anything (No Gridview).
2. On my page, I made something like (username, gender, address, and more) and one single search button. That means, no single control enable auto postback. What I am trying to accomplish is building dynamic query
(if username specifed -> SELECT * FROM [this_table] WHERE [username] LIKE @username).
If both username and gender are specified (SELECT * FROM [this_table] WHERE [username] LIKE @username AND [gender] = @gender) and you know the rest. How can I do this using GridView and SqlDataSource ? To my knowledge, I can only specify one SELECT statement in a sqldatasource.
By right clicking on my database i created a query in server explorer. But where are this query stored can't find them back. I should aspect that their is a folder query's like there is a folder tables but this isn't the case.
I have a web app for our golf club. When I compute handicap index for each golfer, I have to select the most recent scores and then a subset of those scores depending on how many rounds of golf the golfer has played. All the scores are entered into a single SQL Express table called "Rounds". Verbally, this is what I'm trying to do:
1) select the twenty most recent golf scores (sort on date descending, "take(20)") [if less than 20 records, then select all available];
2) for this set of records, select the 10 lowest scores (or smaller number if golfer has less than 20 rounds);
3) compute the average round differential for the subset of records, etc. to calculate handicap index (this step is working ok...)
My current VB code has this LINQ query (which is flawed -- it selects the lowest handicap differential scores of ALL records for the filtered user):
[Code]....
How do I modify this query to accomplish items 1) & 2) above? It seems this should be simple, but my experience with queries is still limited.
