LINQ to DataTable结果过滤

Question

我试图让这个LINQ查询返回完全匹配（如果存在）或“startswith”结果（如果不存在）。现在它返回两者。

例如

SearchParam =“mundt” 结果= Mundt，Mark | Mundt，Chris | Mundth，Lori

public static DataTable SearchPerson(string SearhParam)
    {
        var context = new ConnectDataContext(Properties.Settings.Default.ConnectConnectionString);
        var myQuery = (from person in context.tblPersons
                          where person.LastName.StartsWith(SearhParam) || person.LastName == SearhParam
                          orderby person.LastName
                          select new { person.PersonID, person.LastName, person.FirstName, person.SSN });

        var dataTable = myQuery.CopyLinqToDataTable();

        return dataTable;
    }

Answer 1

尝试：

        var persons = (from person in context.tblPersons
                          orderby person.LastName
                          select new { person.PersonID, person.LastName, person.FirstName, person.SSN });
        var filteredPersonsList = persons.Where(p=>p.LastName == SearhParam).ToList();
        if( filteredPersons.Count == 0 )
             filteredPersonList = persons.Where(p=>p.LastName.StartsWith(SearhParam))
                       .ToList();
        var dataTable = filteredPersonsList.CopyLinqToDataTable();

        return dataTable;

注意：它对数据库进行2次点击，一次查找完全匹配，一次用于startswith（如果没有找到第一次）。

另一种选择是抓住它们，然后在内存中重新过滤。