asp.net - DB Connection string in Web.config to use attached .mdf database won't work

Question

The file neodb.mdf is in my App_Data folder and I can browse the database in the server explorer in visual studio, using built in SQLEXPRESS:

Currently trying to no avail:

 <connectionStrings>
    <add name="EFDbContext" connectionString=".SQLExpress;AttachDbFilename=|DataDirectory|neodb.mdf; Database=neodb;Trusted_Connection=Yes;" providerName="System.Data.SqlClient"/>
  </connectionStrings>

and

 <connectionStrings>
    <add name="EFDbContext" connectionString="Data Source=.SQLEXPRESS;Database=neodb.mdf;Integrated Security=True" providerName="System.Data.SqlClient"/>
  </connectionStrings>

Also as I understand the *.mdf is an SQL server database file type and .dbo is owner of file when it's included in the initial catalog ? What's the initial catalog anywhere ?

Answer 1

If you have the *.mdf placed in App_Data folder, using this format works:

<connectionStrings>
  <add name="ConnectionName"
    connectionString="Data Source=.SQLEXPRESS;AttachDbFilename=|DataDirectory|DatabaseName.mdf;Integrated Security=True;User Instance=True"
    providerName="System.Data.SqlClient" />
</connectionStrings>