数据库管理，创建表，生成的语句没有字段注释 返回

db.DbMaintenance.CreateTable这个方法创建表，字段没有注释，列对象DbColumnInfo指定了ColumnDescription

List<DbColumnInfo> columns = new List<DbColumnInfo>();

 var column = new DbColumnInfo
 {
    DbColumnName = dr.cell,
    ColumnDescription = dr.title,
    PropertyName=dr.title,
    DataType = DbSqlDal.GetDataType( dr.datatype,len),
    DefaultValue = dr.valdefault,
    IsNullable = required,
    IsPrimarykey = pk
 };
columns.Add(column);

 bool b = db.DbMaintenance.CreateTable(tablename, columns);