Question

How do you insert/update a column through Linq To SQL and Linq To SQL use the default values? In particular I’m concerned with a timestamp field.

I’ve tried setting that column to readonly and autogenerated, so it stopped trying to put in DateTime.MinValue, but it doesn’t seem to be updating on updates.

Answer 1

The database default value would only insert the value on creating the row. It would do nothing for update, unless you want to add a triggger.

Alternately, you can add a partial method to your DataContext class. Add a new file you your project:

public partial class YourDatabaseDataContext {     partial void InsertYourTable(YourTable instance)     {         instance.LastUpdateTime = DateTime.Now;          this.ExecuteDynamicInsert(instance);     }      partial void UpdateYourTable(YourTable instance)     {         instance.LastUpdateTime = DateTime.Now;          this.ExecuteDynamicUpdate(instance);     }