Insert and update doesn't change database (sdf)

问题

I have a problem with saving data to database named Settings.sdf. I have few files:

- Settings.sdf
- SettingsDataSet.xsd
 - SettingsDataSet.Designer.cs
 - SettingsDataSet.xsc
 - SettingsDataSet.xss

If I tried use UPDATE or INSERT INTO queries I would not update my database (Settings.sdf), only change data in cache file (whatever and wherever it is). I'm using correctly all SqlCeCommands. For example:

string conString = "Data Source=Settings.sdf";
con = new SqlCeConnection(conString);
con.Open();
...
using (SqlCeCommand com = new SqlCeCommand("UPDATE Settings SET [Value] = (@loc) WHERE [Key] = 'Location'", con))
{
    com.Parameters.AddWithValue("@loc", device.Location);
    com.ExecuteNonQuery();
}
...
con.Close();

How manage this problem? Why this command doesn't update directly my database?

回答1:

You can adjust your database path, you must set full path:

1. Adjust with:

   string conString = "Data Source=" + Path.Combine(Your full path,"Settings.sdf");`
   

2. Add ; at the end of your query

using (SqlCeCommand com = new SqlCeCommand("UPDATE Settings SET [Value] = (@loc) WHERE [Key] = 'Location';", con))
{
...
}

回答2:

the changed maded in the sdf file in debug directory but when you run again the sdf will be created again, remove the create always and test again

来源：https://stackoverflow.com/questions/12072169/insert-and-update-doesnt-change-database-sdf