search in LinqToSQLClasses

Question

How can I search in a table if a record with specific parameter doesn't exist, and then insert the record into table?

Answer 1

if(from t in context.table where t.field.Equals(parameter) select t).Count() == 0)
{
  table t = new table(){ field1 = param1, field2 = param2};
  context.table.InsertOnSubmit(t);
  context.SubmitChanges();
}

And remember to enclose it in a transaction for possible concurrency issues.

Answer 2

MyDataContext db = new MyDataContext();

if (db.table.Where( x => x.ID == id).ToList().Count == 0 )
{
db.table.Add(MyRow);
context.SubmitChanges();
}