/// <summary>
/// 由XmlElement转换成SqlElement
/// </summary>
/// <param name="sqlElement">附加到的SqlElement</param>
/// <param name="xmlParent">反序列化的XmlElement</param>
/// <param name="xnm">命名空间</param>
public override void FromXml(SqlElement sqlElement, XmlElement xmlParent, XmlNamespaceManager xnm)
{
base.FromXml(sqlElement, xmlParent, xnm);
SubQuerySqlStatement selectSql = sqlElement as SubQuerySqlStatement;
ParserUtil util = new ParserUtil(xnm);
XmlElement xmlSelectList = util.Child(xmlParent, SelectFieldListStatement.SELECTLISTSTATEMENT);
XmlElement xmlFrom = util.Child(xmlParent, From.FROM);
XmlElement xmlJoinCondition = util.Child(xmlParent, JoinConditionStatement.JOINCONDITIONSTATEMENT);
XmlElement xmlFilterCondition = util.Child(xmlParent, FILTERCONDITION);
XmlElement xmlOrderByCondition = util.Child(xmlParent, ORDERBYCONDITION);
selectSql.SelectList.FromXml(selectSql.SelectList, xmlSelectList, xnm);
selectSql.From.FromXml(selectSql.From, xmlFrom, xnm);
selectSql.JoinCondition.FromXml(selectSql.JoinCondition, xmlJoinCondition, xnm);
selectSql.FilterCondition.FromXml(selectSql.FilterCondition, xmlFilterCondition, xnm);
selectSql.OrderByCondition.FromXml(selectSql.OrderByCondition, xmlOrderByCondition, xnm);
/*
* MainFromItem只序列化，不反序列化。
* 其反序列化操作已包含在Froms的集合中，直接从集合中取即可。
* */
selectSql.mainFromItem = this.From.ChildCollection[0] as FromItem;
}
/// <summary>
/// 转换成XmlElement
/// </summary>
/// <param name="sqlElement">要转换的对象</param>
/// <param name="xmlParent">附加到的XmlElement</param>
public override void ToXml(SqlElement sqlElement, XmlElement xmlParent)
{
base.ToXml(sqlElement, xmlParent);
SubQuerySqlStatement selectSql = sqlElement as SubQuerySqlStatement;
XmlElement xmlSelectList = SerializerUtil.AddElement(xmlParent, SelectFieldListStatement.SELECTLISTSTATEMENT);
selectSql.SelectList.ToXml(selectSql.SelectList, xmlSelectList);
XmlElement xmlFrom = SerializerUtil.AddElement(xmlParent, From.FROM);
selectSql.From.ToXml(selectSql.From, xmlFrom);
XmlElement xmlJoinCondition = SerializerUtil.AddElement(xmlParent, JoinConditionStatement.JOINCONDITIONSTATEMENT);
selectSql.JoinCondition.ToXml(selectSql.JoinCondition, xmlJoinCondition);
XmlElement xmlFilterCondition = SerializerUtil.AddElement(xmlParent, FILTERCONDITION);
selectSql.FilterCondition.ToXml(selectSql.FilterCondition, xmlFilterCondition);
XmlElement xmlOrderByCondition = SerializerUtil.AddElement(xmlParent, ORDERBYCONDITION);
selectSql.OrderByCondition.ToXml(selectSql.OrderByCondition, xmlOrderByCondition);
/*
* MainFromItem只序列化，不反序列化。
* 其反序列化操作已包含在Froms的集合中，直接从集合中取即可。
* */
XmlElement xmlMainFromItem = SerializerUtil.AddElement(xmlParent, MAINFROMITEM);
selectSql.MainFromItem.ToXml(selectSql.MainFromItem, xmlMainFromItem);
}
