/// <summary>
/// 若存在IndexField，则根据IndexField下移一位。
/// </summary>
public void MoveDown(Transaction trans)
{
if (IndexField != null)
{
var fn = IndexField.Attribute.DbFieldName;
var cur = GetValue(fn);
var where = new Compare(CompareType.LessThan, fn, cur).ToWhere();
where.AddOrder(fn, OrderType.Desc);
_swap_with(where, fn, cur, trans);
}
else
{
throw new IndexFieldException("没有Index字段。", null);
}
}
public static Int64 GetNextIndex(Transaction trans)
{
if (IndexField != null)
{
try
{
var fn = IndexField.Attribute.DbFieldName;
var kn = KeyField.Attribute.DbFieldName;
Command cmd = DbProvider.CreateCommand(string.Format("select {0} from {1}", IndexField.EnsuredName, EnsuredTableName));
Where where = new Compare(CompareType.LessThan, fn, TopLimit).ToWhere();
where.AddOrder(fn, OrderType.Desc);
Builder.AppendWhere(cmd, where, kn, DbProvider.Adapter);
Builder.AppendPage(cmd, kn, TableName, new Page(0, 1), where, DbProvider.Adapter);
return(Convert.ToInt64(
cmd.ExecuteScalar(trans)
) + 1);
}
catch { return(StartIndex); }
}
else
{
throw new IndexFieldException("没有Index字段。", null);
}
}