如何在linq查询中对不同的列进行分组?

只需使用由这些属性组成的匿名密钥进行分组。下面是C查询的语法:

var query = from row in joinedTable
            group new // subgroup record
                {
                    row.ColumnName,
                    row.PreviousValue,
                    row.NewValue
                }
            by new    // group record
                {
                    row.DateStamp,
                    row.UserName,
                    row.StudentName,
                    row.InstructorName,
                    row.TableName,
                    row.PrimaryKey
                };

Dim query = From row In joinedTable    _
            Group                      _
                row.ColumnName,        _
                row.PreviousValue,     _
                row.NewValue           _
            By                         _
                row.DateStamp,         _
                row.UserName,          _
                row.StudentName,       _
                row.InstructorName,    _
                row.TableName,         _
                row.PrimaryKey         _
            Into SubGroup = Group