实体框架 - 为“providerInvariantName'参数期待非空字符串 [英] Entity Framework - Expecting non-empty string for 'providerInvariantName' parameter

问题描述

好吧，这可能不与EF。我试图用code-第一特征，下面是我写的： -

Ok, this may not be related to EF. I am trying to use the code-first feature and following is what I wrote:-

var modelBuilder = new ModelBuilder();
            var model = modelBuilder.CreateModel();
            using (AddressBook context = new AddressBook(model))
            {
                var contact = new Contact
                {
                    ContactID = 10000,
                    FirstName = "Brian",
                    LastName = "Lara",
                    ModifiedDate = DateTime.Now,
                    AddDate = DateTime.Now,
                    Title = "Mr."

                };
                context.contacts.Add(contact);
                int result = context.SaveChanges();
                Console.WriteLine("Result :- "+ result.ToString());

            }

上下文类： -

The context class:-

public class AddressBook : DbContext
    {
        public AddressBook()
        { }
        public AddressBook(DbModel AddressBook)
            : base(AddressBook)
        {

        }
        public DbSet<Contact> contacts { get; set; }
        public DbSet<Address> Addresses { get; set; }
    }

和连接字符串： -

and the connection string:-

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <connectionStrings>
    <add name="AddressBook"  connectionString="Data Source=MyMachine;Initial Catalog=AddressBook;Integrated Security=True;MultipleActiveResultSets=True;providerName=System.Data.SqlClient"/>
    </connectionStrings>
</configuration>

所以，数据库名称为通讯录，当我初始化地址簿对象的错误发生。我看到有人建议增加（的providerName =System.Data.SqlClient的）的连接字符串。不过，这并不在我的情况下工作。我缺少什么吗？

So, the database name is "AddressBook" and the error happens when I initialize the AddressBook object. I see people suggesting to add (providerName="System.Data.SqlClient") to the connection string. But It does not work in my case. Am I missing anything here?

推荐答案

您应该添加System.Data.SqlClient的作为值到一个名为的ProviderName的新属性。就像如下： -

You should add the System.Data.SqlClient as the value to a new attribute named "ProviderName". Just like below :-

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <connectionStrings>
    <add name="AddressBook" providerName="System.Data.SqlClient"  connectionString="Data Source=MyMachine;Initial Catalog=AddressBook;Integrated Security=True;MultipleActiveResultSets=True;"/>
    </connectionStrings>
</configuration>

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