DataSource Controls :: Breaking Long Query Into Small One Using SQLDataSource?
Oct 25, 2010
Currently, I have long script which does major processing and then puts data into temp table.
Finally I read data from this temp table to show on the chart, based on user's selection of parameter. So I can divide my query into two parts and while I am researching this,
Is it possible to do processing in one Datasource and read table from second datasource?Is it even possible?
If not, what is recommended method for this (breaking large processing into small one)?
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.
I have an editable grid where user can add/edit data. They also have the option to load previously entered data from last month. When the user then clicks save, i want to readd this newly modified data as a new record for this month. So basically I want to call the insertcommand, but it does not work. My 'save' method just 'updates' the records.
Providing sqldatasource, grid and save method <asp:SqlDataSource ID="SqlDataSourceLoadActivities" runat="server" [code].....
I have a strange problem...I am programatically adding an SQL SELECT query to my SqlDataSource that my GridView is bound to. If I use the follwing statement it works fine:
[Code]....
But if I use the following one, the gridview fails to load. The only way that this is different is it uses RTRIM and CAST on one of the fields:
[Code]....
I don't understand why this can be. If I try the statement exactly how it is in the query builder and run it it returns the rows no problem.
I have a gridview which I connect by C# and SqldataSource. I use asp.net 2.0 - 3.5.
I want to parameterized the queries and how do I do this in the C# file ? how do I set the selectparameters in C# ?. I do not want to do this in the aspx fil.
My code in C# is:
SqlDataSourceMachineName.SelectParameters.Clear(); SqlDataSourceMachineName.SelectCommand = "Select MachineName from tblMachine inner join tblLocation on tblMachine.MachineLocationID = tblLocation.LocationID where tblLocation.LocationName = 'New York' and tblMachine.StatusID = '1'";
<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 have a query that I want to test the performance of when the query is included directly in the SqlDataSource versus when I call a stored procedure. Does anyone have suggestions on how I would be able to closely watch the actual steps here? I was thinking of turning on tracing and adding Trace.Write for each of the events that fire along the way. This doesn't seem efficient and I wanted to see if there was a better approach.
What ive been using now is getting datas in code-behind, passing datasource into a Session, re-binds it to a gridview whenever there's paging/sorting needed. What i want to know is what is better if its performance we are talking about?
Is it datasource into a session Or SqlDataSource for which I know whenever paging/sorting needed is that sqldatasource opens up a DB connection to get the datas again?
In Entity framework I have a class which is effectively
fooEntity { public Guid Id {get; set;} and a collection of fooChildEntity } a fooChildEntity is again an entityframework class fooChildEntity { public Guid kidId {get; set;} }
Now I also have a pair of business layer classes foo and fooChild
foo { public Guid Id {get; set;} ilist<fooChild> Children {get;set;} } fooChild { public Guid kidId {get; set;} }
My aim is to write a linq to entites that will allow me to convert the entity foo and children into the business foo and children without breaking deferred execution ( I will be adding filters to reduce the recordset at a higher coding level in the business layer)
doing something like
this.context.fooEntity
.include(fooChildEntity)
.Select( fe => new foo { Id=fe.Id ,
fe.foreach(fec => Children.add( new fooChild { kidId = fec.kidId}))})
.AsIQueryable()
is plainly rubbish and would never compile - it is however an indication of the direction I was thinking .
Even if I got a foreach to work like that or similar it would break deferred execution
At this point there are around 300,000 foo entities which I will eventualy filter to 5 or 6 foo's - this is why deferred execution is needed.
Say I need to populate 4 or 5 dropdowns w/ items from a database. Each drop down will have < 15 items in it. These items almost never change.
Now I could query the DB each time the page is accessed or I could grab the values from a custom class that would check to see if they already exist in ASP.Net's cache and only if they don't query the DB to update the cache.
It's trivial for me to write but I'm unsure if the performace would be better or not. I think it would be (although not likely anything huge).
I've been wrestling with this for a while. What I want to do SEEMS like it would be very simple, buy nothing about it so far has been. Any assistance would be absolutely outstanding.Basic concept of what I want to do is...
i have two sqldatasource controls. one i use to display data in textbox's ,filter'd by a select parameter in page behind code. Once checked, i want to copy this data to the other datasource ,by selecting checkbox.Then display this data in detailsview control.
At present the two datasource controls declared , render data to the page simultaneously during pageload. I want to first check data in textbox's from first source, before second datasource is rendered to screen. note, both are filtered by a page variable. i wish to leave the textbox datasource control in situ, as other controls and code depend on it.The other detailsview datasource is my problem?
When i create a sql script in the Query Builder (going through the wizard in a DataSet) the Query Builder window is to small for me. Is there a way to maximize this window by default?PS, I have previously posted this in the forum "Visual Studio 2008.
My SelectCommand string in my asp:SqlDataSource is very long. Is there a way I can chop it up into different strings on several newlines to make it more readable?
I'm using VS2008 to write a web app. The page has 3 inputs (select date from calander, and items from two dropdownlists). User will be able to select any of the three or nothing. I start with a "select * from ... and append a where stmt to my select; depending on the user's choices. Once the user has selected (or not) they will click a "get info" button. That passes the select command to the SQLDATASOURCE, where it successfully returns what was requested. If I have PAGING enabled (perferred because there could be MANY rows returned), the first 10 rows return with the appropriate page numbers. When a page number is picked (ie. 2 or next), the page reloads and the query reruns but regardless of the original query; the rerun query selects everything. Obviously, this will not work.i'll even ZIP my code and email it to "you"; if needed.
I have a site that calls a long running stored procedure that eventually times out the UI. The procedure simply runs some logic in the database, and kicks of a secondary process. No data is ever returned to the UI, so I don't need the UI to wait for anything.Is there a way to call the stored procedure from the UI and move on without having the UI having to wait for the store procedure to complete?
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.
