I 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();
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??
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?
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.
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?
I 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?
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 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?
what is diffrence between Entity Framework and LINQ to SQL i cant yet find a good blog on this i have read that in LINQ to SQL only one to one mapping is possible but Entity Framework allowes many , is it right? if so i dont understand this
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've got a ListView with a DataPager on one page and then a FormView with the items detailson another page. There is an Image in the ListView where the user can click on the image andthat takes them through to the page with FormView on it.If the user goes through to the FormView page and then press's back on the browser to takethem back to the page with the ListView on if the user then click's on the DataPager it takes
I've added a database to one of my projects and I'm wondering how I can get intellisense for them.
Basically I have no how I can query the database that I've added to the project. I know SQL fairly well, but I don't know how I can write queries within vb.net and have them display.
I can get, so intellisense will probably be invaluable.
I have a query which gets the text from a textbox and inputs it into the database.
It works fine if the value is something like Taylor but errors when it's O'Neill because the apostrophe gives a syntax error unclosed quotation mark Is there a way to add O'Neill to the database with the apostrophe still there?
I don't want to replace it with a double single quote I want it to be put in the database as it shows.
I am using linQ for get these data to silverlight so I cant use execute query in silverlight and have to go with LInQ. can someone point me for easier way to convert similar queries or any tips.
In my web application, I need to run a lot of sql queries for a specific operation. For example, first I run a select command , get results. If they fulfill my requirement, I insert some values by insert command, else I update and insert...and so on. I need to execute 8-10 commands for each specific operation. For this , I have created a <asp:Sqldatasource> in aspx page and I run queries by SqlDataSource1.Select, SqlDataSource1.InsertCommand etc. I dont think , its a right approach . Further, I need to preserve data consistency. Say my 5 commands executes successfully and then sql or something else, throws an error and 5 commands left untouched. Then, it will create me a problem. And my current logic will fail, as it works on step by step basis.
