MySQL +实体框架中的对象刷新错误

Question

I am trying to learn entity framework with MySql database.
Trying to save the data with following code:

protected void btnSubmit_Click(object sender, EventArgs e)
{
    if (txtName.Text == string.Empty ||
    txtAge.Text == string.Empty)
    {
        lblMsg.Text = "Please enter proper details first";
        return;
    }

    employee emp = new employee();
    emp.Name = txtName.Text;
    emp.Age = Convert.ToInt32(txtAge.Text);

    using (entityframeworkEntities context =
    new entityframeworkEntities())
    {

        context.AddToemployees(emp);
        if (context.SaveChanges() == 1)  // Error Part
        {
            lblMsg.Text = "Saved Successfully.";
        }
    }
}

The code is getting an Object Reference error on if (context.SaveChanges() == 1) . Even the emp is not added to the contaxt object.

When I debug the code, the debugger goes to following part:

public entityframeworkEntities() :                               
base("name=entityframeworkEntities", "entityframeworkEntities") 
{
    this.OnContextCreated();   
}

Even on this part, the debugger comes to the braces but skip this.OnContextCreated(); line.

Here is my connection string in Web.Config

<add name="entityframeworkEntities" connectionString="metadata=res://*/ApplicationWithMySql.csdl|res://*/ApplicationWithMySql.ssdl|res://*/ApplicationWithMySql.msl;provider=MySql.Data.MySqlClient;provider connection string=&quot;server=localhost;User Id=root;password=root;database=entityframework&quot;" providerName="System.Data.EntityClient" />

Please help me, where am I going wrong?

Thank you!

Answer 1

Just a couple of things u might have overlooked. not so much an answer. quite long to post as a comment

<system.data>
    <DbProviderFactories>
        <remove invariant="MySql.Data.MySqlClient" />
        <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.3.5.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d" />
    </DbProviderFactories>
</system.data>

a.build clean.

b.build mysql dll into ur bin directory

c.Install nuget packages for MySQL.Data and MySQL.Data.Entities.((right click on assembly and ensure Copy Local is set to true before building)

d.Remove Version=6.3.5.0 tag entirely and build without any versioning on VS.type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data" instead of specifying the full version data.