实体框架和SQL Server数据库连接字符串

Question

I have worked with EF for a while now and i have always used LocalDb's for storing data. I want to start working with SQL Server databases instead but I'm having some issues setting up the connection string.

https://msdn.microsoft.com/en-us/library/jj653752(v=vs.110).aspx#sse https://www.connectionstrings.com/

and looked over google but none of the answers made it work in my case so I must be doing something wrong (some of the connections strings throw an exception others didn't but wouldn't insert anything either into the database neither)

My question is when working with EF & SQL Server, should I use both the connection string in the App.config & setting the path of the DB in the CTOR of the context (by using AppDomain.CurrentDomain.SetData("DataDirectory", path); ) or is the app.config sufficient ?

I have tried the following connection strings:

Data Source=.\GURUBEAST-PC\GURUSQL;Initial Catalog=iManager;Trusted_Connection=True;MultipleActiveResultSets=True;

Data Source=.\GURUBEAST-PC\GURUSQL;Database=iManager;Integrated Security=True;Trusted_Connection=True;MultipleActiveResultSets=True;

Data Source=.\GURUBEAST-PC\GURUSQL;AttachDbFilename=C:\Program Files\Microsoft SQL Server\MSSQL11.GURUSQL\MSSQL\DATA\iManager.mdf;Database=iManager;Trusted_Connection=True;MultipleActiveResultSets=True;

Data Source=.\GURUBEAST-PC\GURUSQL;AttachDbFilename=C:\Program Files\Microsoft SQL Server\MSSQL11.GURUSQL\MSSQL\DATA\iManager.mdf;Database=iManager;Trusted_Connection=True;

Data Source=.\GURUBEAST-PC\GURUSQL;Database=iManager;Trusted_Connection=True;

Data Source=.\GURUBEAST-PC\GURUSQL;Initial Catalog=iManager;Integrated Security=SSPI;

Data Source=.\GURUBEAST-PC\GURUSQL;Initial Catalog=iManager;User id=GURUBEAST-PC\GuruBeast;

Where "iManager" is the name of the database. I use Windows auth for my SQL Server instance.

What am I doing wrong ? Should I set my path to the program files folder or the App_Data (I have seen both and tried both but both didn't work)?

Kind regards!

Answer 1

Once you get your host name figured out, Entity Framework will generate your connection string for you. Here's a sample of what your connection string could look like if you were attempting to connect to AdventureWorks database hosted on your local instance of SQL Server 2014 aptly named sql2014.

<connectionStrings>
    <add name="AdventureWorksEntities" connectionString="metadata=res://*/DataModels.AdventureWorksDb.csdl|res://*/DataModels.AdventureWorksDb.ssdl|res://*/DataModels.AdventureWorksDb.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=.\sql2014;initial catalog=AdventureWorks;persist security info=True;user id=App_AdventureWorks;password=asdasdfasdfasdf;MultipleActiveResultSets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />
</connectionStrings>

Your db context would then look something like this.Again, EF generates this for you.

public partial class AdventureWorksEntities : DbContext
{
    public AdventureWorksEntities()
        : base("name=AdventureWorksEntities")
    {
    }

Answer 2

The Data Source key is used to find the machine on which the Sql Server instance runs.
You can have different strings for it but the most common used in a LAN environment is composed using the name of the server machine followed by an eventual instance name.

So, if your local PC is named GURUBEAST-PC and, at install time, you haven't specified any instance name, the connectionstring Data Source contains only the name of the machine GURUBEAST-PC . If you have an instance name then you should add that instance name to you Data Source key. GURUBEAST-PC\\GURUSQL

This will guarantee to all the PC in the same LAN the possibility to have the same connectionstring also if the connection is made from the same PC where the SQL Server runs.

If the Data Source points at the local pc, you can use many shortcuts to represent the local PC:

(LOCAL)
localhost
.
\.

and eventually add the instance name to these shortcuts without repeating the PC name