I'm trying to do something that on the face of it is very simple.
If I have 5 text boxes, and 1 of them is blank, I want to exclude that textbox from the query, rather than searching for where a field is blank.
I've tried to do a bit of research into dynamic linq queries, but have come up empty handed, or what I've found doesn't seem to quite answer my question.
I've added the Dynamic.cs file to my project and have set it's Build Action = Compile in order to get the System.Linq.Dynamic namespace.
However, when I try to use any of the new code I am getting an ambiguous call error; see below.
[Code]....
I've build a linq query.But i want a random selection so its not always ID : 1,2,3,4,5,6 How can i randomize this var? I like to bind it to a repeater.//TagCloud:
Random rand = new Random();
var tc1 = from i in JumpTide.cms.menu.GetMenuItems(32)
select new
[code]...
When i see MVC Music store. They have used ADO.NET entity data model and used LINQ language to perform operation in DB.. Is there any way to use normal sql queries?
View 3 RepliesHow to convert SQL Queries to Linq.is their any tool available to convert SQL Queries to Linq
View 2 RepliesI use LINQ-SQL as my DAL, I then have a project called DB which acts as my BLL. Various applications then access the BLL to read / write data from the SQL Database.
I have these methods in my BLL for one particular table:
public IEnumerable<SystemSalesTaxList> Get_SystemSalesTaxList()
{
return from s in db.SystemSalesTaxLists
select s;
}
public SystemSalesTaxList Get_SystemSalesTaxList(string strSalesTaxID)
{
return Get_SystemSalesTaxList().Where(s => s.SalesTaxID == strSalesTaxID).FirstOrDefault();
[Code].....
Is it possible to combine these 2 linq queries ?
[Code]....
I have my Linq query in which i need to find time difference(not days difference).
The field in database is datetime.
Dim ldtToday
As DateTime = TimeOfDay
Dim SR_RM_InnerJoin =
From SR
In lcntxRT60Entities.RtSReports _
Join RM
In lcntxRT60Entities.RtRMaster
On SR.RtRMaster.ReportID
Equals RM.ReportID _
Select SR, RM _
Where SR.TID = 1 _
And --(Check) SR.ReportDeliveryTime.Value.AddDays(1) < ldtToday
How can i check if the time field of the record is less than current time??
A sample linq query from MSDN: var expensiveInStockProducts = from p in products where p.UnitsInStock > 0 && p.UnitPrice > 3.00M select p; Does this query select EVERY column from the database table immediately, or does it return some sort of pointer that retieves the actual column data on demand? ie. If there are 50 columns in my table and I only use a single p.UnitsInStock in my actual code, then am I retrieving 50 times more data than I expected?
View 2 RepliesI am creating entries in a contract table using linq to sql.
One column needs to conditionally be assigned an application number from a range of values.
I'd like to simply increment the max existing value, however it is a multi-user application and I'm concerned about multiple contracts receiving the same app number if they happen too close together.
Is there a way to either force the entire thing to use the same transaction, or to execute both during the same submit?
how to improve the application performance while writing LINQ Queries ?Like the optimization techniques.
View 2 RepliesI've got the following LINQ query to my IQueryable service
Dim eventcount = EventService.QueryEvents().Count
Dim eventlist = EventService.QueryEvents().Skip((page - 1) * 5).Take(5).ToList
But I'm wondering if there's a way to do this without making two calls to the database?
i want to get masterized....in MVC
finding books and links for mvc..and learning linq queries
Is there a way to cap the number of records returned when an .Include() method is called on an ObjectQuery<>? Basically, if one of my entities is in a one-to-many relationship, such as a Band entity to a list of Fan entities (where a band can have any number of fans), how can I limit the number of fans returned?
In the example: var band = ctx.Bands.Include("Fans").SingleOrDefault(b => b.BandId == someBandId);
If I use the Include, it will return all fans. How can I query that Fans navigation property to return only a subset or max?
I've got a linq to sql query that pulls data from 2 different tables and contains an or statement:
[Code]....
The problem I've got is that some queries match both sides of the or statement so it returns the same record twice.
How can I eliminate these duplicates quickly and easily?
I am working on asp.net 3.5 and in MVC using Linq to SQL classes. In my MVC project i am calling stored procedure using linq to sql that conatin query joining two tables.Below is my code in Partial class
[
Function(Name="dbo.GetUserWiseThreadDetail_SP")]
[ResultType(typeof(Thread))]
[ResultType(typeof(Reply))]
public
IMultipleResults GetUserWiseThreadDetail_SP([Parameter(DbType="VarChar(30)")]
string userID)
{
ExecuteResult result = this.ExecuteMethodCall(this,
(MethodInfo)(MethodInfo.GetCurrentMethod())), userID);
return ((IMultipleResults)(result.ReturnValue));
}
In one of the controller i have made one more class
public class
MypostIndexData
{
public
IEnumerable<Thread> Thrds {
get;
set; }
public
IEnumerable<Reply> Repls {
get;
set; }
public MypostIndexData(IEnumerable<Thread>
thrds,IEnumerable<Reply> repls)
{
this.Thrds=thrds;this.Repls=repls;
}
}
finally coding of controller action method
ForumDataContext pmforum = new
PMForumDataContext();
public
ActionResult MyPosts(string userId)
{
IEnumerable<Thread>thrds;
IEnumerable<Reply>repls;
IMultipleResults result = pmforum.GetUserWiseThreadDetail_SP(userId); (this satement doesnot give any result,if i execute stored proc in
sql it give the results)
thrds = result.GetResult<Thread>();
List<Thread> thrdlist =
new
List<Thread>(thrds);
repls = result.GetResult<Reply>();
List<Reply> replylist;
if (repls !=
null)
{
replylist = new
List<Reply>(repls);
}
return View(new
MypostIndexData(thrds,repls));
I am unable to understand why i am not getting any results?
Is there a way to combine the LINQ queries together and have access to both of the results independently?
[Code]....
We would like to perform something like this
string strCondition = "FirstName=='abc'"
from p in People.Where(strCondition) select p
In our architecture we are usign both Linq-Sql as well Linq-Entity. So please give some thoughts wehter it is possible or not and is there any way to perform this?
For comparison: something like the shirt builder application at [URL] Say, if I have fabric image and want to generate base, collar, cuff etc. How should I do it on server side in .NET, and generate different components of shirt.
View 1 RepliesIf i split the statements up they work fine individually.But what im trying to accomplish is to pass in the column name that i want to select from my table.. ill pass it from the page as well as 1 other parameter.
I was looking and found some queries that will return the column name from the table but figured this may work.when i execute this,it returns the actual value in my SET @column line.so in the below code if i run it, it will just return the value "VideoLevel"
BUT if i change it to the example below that,it works..
[Code]...
[Code]...
I'm currently trying to work out the best way to build this web application, which will then be intergrated on other systems, such as WinForms, Intranets etc.
We hope to include the usual layers i.e. DAL, BLL, BOL and UI but I have been experimenting with Entity Framework 4 and WCF Data Services and managed to get something in place where I was using WCF as a gateway to EF4.
i.e. Adding a Service Reference to my project and then using the EF4 context and writing LINQ queries against the DB
e.g.[Code]....
Now with the current setup I would still need to write a DAL Class Library, that interacts with the Data Service, because as I said WCF Data Services only seems to be a gateway, I can't see where to put the code (above) in the Data Service and then how I could these methods.
My questions are: 1. How do I develop a WCF Data Service in such a way to allow this behaviour - I know how I could do it using ASMX web service, something like [Code]....
2. If I am to use WCF Data Services, how is serialization handled (if at all) - again I know how to do something in ASMX web services
3. Again, If I am to use WCF, how do I add Security and only allow my applications to access the web service - for obvious reasons
4. Would it be possible / logical to also include the Business Logic Layer into the web service?
i want to build dynamic sitemap from database..even my menu items are also dynamic...and i want do display sitemap having categories and related menu items from database..
so i dont know how to build dynamic site and create dymanic links of that menus and categories..
I'm currently writing a web app in ASP.NET MVC 1.0 (although I do have MVC 2.0 installed on my PC, so I'm not exactly restricted to 1.0) -- I've started with the standard MVC project which has your basic "Welcome to ASP.NET MVC" and shows both the [Home] tab and [About] tab in the upper-right corner. Pretty standard, right? I've added 4 new Controller classes, let's call them "Astronomer", "Biologist", "Chemist", and "Physicist". Attached to each new controller class is the [Authorize] attribute. For example, for the BiologistController.cs
[Authorize(Roles = "Biologist,Admin")]
public class BiologistController : Controller
{
public ActionResult Index() { return View(); }
}
These [Authorize] tags naturally limit which user can access different controllers depending on Roles, but I want to dynamically build a Menu at the top of my website in the Site.Master Page based on the Roles the user is a part of. So for example, if "JoeUser" was a member of Roles "Astronomer" and "Physicist", the navigation menu would say:
[Home] [Astronomer] [Physicist]
[About]
And naturally, it would not list links to "Biologist" or "Chemist" controller Index page. Or if "JohnAdmin" was a member of Role "Admin", links to all 4 controllers would show up in the navigation bar. Ok, you prolly get the idea... Now for the real question... Starting with the answer from this StackOverflow topic about Dynamic Menu building in ASP.NET, I'm trying to understand how I would fully implement this. (I'm a newbie and need a little more guidance, so please bare with me.) The answer proposes Extending the Controller class (call it "ExtController") and then have each new WhateverController inherit from ExtController.
My conclusion is that I would need to use Reflection in this ExtController Constructor to determine which Classes and Methods have [Authorize] attributes attached to them to determine the Roles. Then using a Static Dictionary, store the Roles and Controllers/Methods in key-value pairs. I imagine it something like this:
public class ExtController : Controller
{
protected static Dictionary<Type,List<string>> ControllerRolesDictionary;
protected override void OnActionExecuted(ActionExecutedContext filterContext)
{
// build list of menu items based on user's permissions, and add it to ViewData
IEnumerable<MenuItem> menu = BuildMenu();
ViewData["Menu"] = menu;
}
private IEnumerable<MenuItem> BuildMenu()
{
// Code to build a menu
SomeRoleProvider rp = new SomeRoleProvider();
foreach (var role in rp.GetRolesForUser(HttpContext.User.Identity.Name))
{
}
}
public ExtController()
{
// Use this.GetType() to determine if this Controller is already in the Dictionary
if (!ControllerRolesDictionary.ContainsKey(this.GetType()))
{
// If not, use Reflection to add List of Roles to Dictionary
// associating with Controller
}
}
}
Is this doable? If so, how do I perform Reflection in the ExtController constructor to discover the [Authorize] attribute and related Roles (if any) ALSO! Feel free to go out-of-scope on this question and suggest an alternate way of solving this "Dynamic Site.Master Menu based on Roles" problem. I'm the first to admit that this may not be the best approach.
how to indicate which columns I would like returned at run-time from a LINQ To SQL statement?I am allowing the user to select items in a checkboxlist representing the columns they would like displayed in a gridview that is bound to the results of a L2S query.I am able to dynamically generate the WHERE clause but am unable to do the same with the SELECT piece. Here is a sample:
var query = from log in context.Logs select log;
query = query.Where(Log => Log.Timestamp > CustomReport.ReportDateStart);
query = query.Where(Log => Log.Timestamp < CustomReport.ReportDateEnd);
[code]...
I have a table created on the fly. The table structure is dynamic.
This is the table structure generated by the end of year 2010
DealerCode, 201010, 201011, 201012
This is the table structure generated by the end of Jan 2011
DealerCode, 201011, 201012, 201101
What I need to do is selecting all data and then bind it into a gridview
To build a LINQ query, we need to drag the table into dbml file first. As we don't know how the table look like, can we add it in dynamically? Are there any other solutions?