获取实体框架连接字符串

Question

We use Entity Framework 5, but have a requirement to ALSO use a normal database connection from the application for some custom SQL we need to perform.

So, I am creating a DatabaseAccess class which handles this connection. Is there a way that I can populate the connection string, by checking the Entity Framework connection string?

So:

SqlConnection cnn;
connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password"

Can I build that from checking Entity Framework?

Answer 1

You can get the connectionstring used by EF by using the following:

MyDbContext.Database.Connection.ConnectionString

Or as mark says you can initalise the context with a sqlconnection

Answer 2

Here's how to get the connection string in EF 5, EF 6 and EF Core 1/EF 7.

//Entity Framework 5
myContext.Database.Connection.ConnectionString
//Entity Framework 6
myContext.Database.Connection.ConnectionString
//Entity Framework Core 1
myContext.Database.GetDbConnection().ConnectionString

For more details see - http://nodogmablog.bryanhogan.net/2016/04/entity-framework-checking-the-connection-string-of-your-context/

Answer 3

Yes you can.

See here for 3 options.

1 - use separate connection string for each

2 - extract it from your entity object (this is what i think you want)

3 - use the entity object to execute your custom SQL

Here's how to do nr 2:

using System.Data.EntityClient;
using System.Data.SqlClient;
...
private string GetADOConnectionString()
{
    SalesSyncEntities ctx = new SalesSyncEntities(); //create your entity object here
    EntityConnection ec = (EntityConnection)ctx.Connection;
    SqlConnection sc = (SqlConnection)ec.StoreConnection; //get the SQLConnection that your entity object would use
    string adoConnStr = sc.ConnectionString;
    return adoConnStr;
}

Answer 4

even in EF3 you can use EntityConnectionStringBuilder.

EntityConnectionStringBuilder conn = 
    new EntityConnectionStringBuilder(DBEntities.dbConnection);
SqlConnection s = new SqlConnection(conn.ProviderConnectionString);

Answer 5

Do you mean, can you use a SqlConnection with your EF DbContext?

The DbContext class has a constructor where you can pass in a SqlConnection, and then tell EF whether or not it owns it.

var YourContext = new YourContext(SqlConnection, true);

Answer 6

//Entity Framework 5

myContext.Database.Connection.ConnectionString

//Entity Framework 6

myContext.Database.Connection.ConnectionString

//Entity Framework Core 1

myContext.Database.GetDbConnection().ConnectionString

Answer 7

I had this problem too, to solve the problem you can do this:

        SqlConnection con = context.Database.Connection as SqlConnection;
        SqlCommand command = new SqlCommand(sql, con);
        con.Open();

        SqlDataReader reader = command.ExecuteReader();
        while (reader.HasRows)
        {
            while (reader.Read())
            {
                //read your fields
            }

            reader.NextResult();
        }

        con.Close();

Answer 8

Hope it helps..

    private readonly ApplicationDbContext _applicationDbContext;
    string connectionString = string.Empty;

    public CommonService(ApplicationDbContext applicationDbContext)
    {
        _applicationDbContext = applicationDbContext;
        connectionString = _applicationDbContext.Database.GetDbConnection().ConnectionString;
    }

Answer 9

Here is a generic way of getting the connection string:

   public string GetConnString<T>(T ent)
            where T : ObjectContext
        {
            EntityConnection ec = (EntityConnection)ent.Connection;
            SqlConnection sc = (SqlConnection)ec.StoreConnection;
            return sc.ConnectionString;
        }

Then to use it would be:

 MyEntities ent = new MyEntities();
 String ConnString = GetConnString(ent);

Answer 10

In my case I just needed to execute an update statement so I used the following construct

_db.Database.ExecuteSqlCommand($"update ChiusureTurni set esportato = 1 where idChiusuraTurni = {idChiusura}");

where _db is my db context in this case I took advatage of transaction management

Answer 11

If you want to get the (SQL) connection string without instantiating the Entity Context/establishing an entity connection, we can use the EntityConnectionStringBuilder:

string entityConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings[entityName].ConnectionString;
var entitybuilder = new System.Data.EntityClient.EntityConnectionStringBuilder(entityConnectionString);
string sqlConnectionString = entitybuilder.ProviderConnectionString;

To get/set a component of the sql Connection string, replace the last line with:

var sqlBuilder = new System.Data.SqlClient.SqlConnectionStringBuilder(entitybuilder.ProviderConnectionString);
string sqlConnectionString = sqlBuilder.ConnectionString;
Console.WriteLine("Environment: " + sqlBuilder.DataSource);