I ran across a similar issue. The cause was rather straightforward. One of my tables lacks a primary key since I neglected to establish one. Hope it's useful.
In my SQL Server database, I've made certain modifications to the table structure, particularly the connections between tables. Now that the database schema has changed, I want to update my entity model to reflect it....I can choose the "Update model from database" option by selecting "right click" on the edmx file. However, I only receive around a...
Entity Framework allows for the development of queries in one of two ways:...Entities with Linq ( ...http://msdn.microsoft.com/en-us/library/bb386964.aspx... )...SQL Entity ( ...http://msdn.microsoft.com/en-us/library/bb387145.aspx... )...L2E is a component of EF rather than a distinct technology....For comparison, have a look at this article: ...h...
Foreign key relationships in the entity structure are giving me problems. I've got two tables....Persons...
and ...Countries...
. ...Persons...
Includes a column for foreign keys....CountryId...
....As the...Countries...
table doesn't change often, thus I simply want to get its data once and discard it....DatabaseContext...
and maintain a list of....
How should I upgrade the database using ...ORM... (...XPO DevExpress..., ...NHibernate..., or ...Office Entity Framework...)?...I have to choose a ...ORM... for a new project I'm beginning. The release of intermediate test builds is necessary for the development process, and it is probable that each build will include modifications to the database ...
The world was in order when I added a new column to a database table in Visual Studio 2010 EF 4 and then selected "Update Model from Database" on my.edmx file....When I modify a table in Visual Studio 2012 EF 5 and then click "Update Model from Database," it no longer picks up the changes to specific tables....Do I have this right, or is this a bra...
Zzz-5-Zzz would be very similar to the following:...var id = 42;
using(var ctx = new Entities()){
var query = ctx.Companies.Where(o=>o.Id==id);
var result = query.First();
}
...A query is all it is before I call First(). The database has not received any data. The query won't run or the data obtained until data is requested....Lambda is simple ...
Utilizing a Current Database...You need to do one of the following, depending on the situation in your setting......DO THE FOLLOWING IF YOUR DATABASE CONTEXT ONLY CONTAINS YOUR EXISTING TABLES AND NO CUSTOM CHANGES....Add-Migration Initial -IgnoreChanges
...With this, a new migration script will be created....update-database
...The database will be...
Dapper or ADO + Sprocs won't suddenly make slow-running EF-based code run quicker. You must look into and get rid of the reasons of the performance difficulties if you want to solve the performance issue....These performance concerns are the result of two main issues, according to the top level....overloading with data...frequent data loading...The...
