/// <summary>
/// 构造左连接SQL
/// </summary>
/// <param name="sql">Select语句</param>
/// <param name="association">关联</param>
private void BuildLeftJoin(SelectSqlStatement sql, InternalAssociation association, SqlBuildingContext context)
{
LeftJoinItem leftJoin = new LeftJoinItem();
leftJoin.LeftJoinTable = association.LocatedTable;
foreach (var item in association.Association.Items)
{
SqlTable srcElelemtTable = association.LocatedTable;
var srcElement = association.LocatedNode.Elements.FirstOrDefault(i => i.ID == item.SourceElementID);
var targetElement = association.AssociatedCoNode.Elements.FirstOrDefault(i => i.ID == item.TargetElementID);
var leftCol = association.LocatedDataObject.Columns.FirstOrDefault(i => i.ID == srcElement.DataColumnID);
var rightCol = association.AssociatedDataObject.Columns.FirstOrDefault(i => i.ID == targetElement.DataColumnID);
JoinConditionItem joinItem = new JoinConditionItem();
joinItem.LeftField.Table = srcElelemtTable;
joinItem.LeftField.FieldName = leftCol.ColumnName;
joinItem.LeftField.IsUseFieldPrefix = true;
joinItem.RightField.Table = association.AssociatedTable;
joinItem.RightField.FieldName = rightCol.ColumnName;
joinItem.RightField.IsUseFieldPrefix = true;
leftJoin.ChildCollection.Add(joinItem);
}
//关联上的条件
leftJoin.AdditionalCondition = this.ParseCondition(association);
sql.MainFromItem.ChildCollection.Add(leftJoin);
}
/// <summary>
/// 处理关联
/// </summary>
/// <param name="sql">Select语句</param>
/// <param name="context">SQL构造上下文</param>
/// <param name="association">关联</param>
private void HandlingAssociation(SelectSqlStatement sql, SqlBuildingContext context, Association association)
{
if (association.AssoDomainObject == null)
{
throw new Exception("Association cannot find Associate Model: " + association.ID);
}
if (association.AssoDomainObject == null)
{
throw new Exception("Association cannot find Associate ModelObject: " + association.ID);
}
if (association.AssoDomainObject.DataObject == null)
{
throw new Exception("Association cannot find Associate DataObject: " + association.ID);
}
//关联中使用的SqlTable,通过关联的ID进行标识，存在一个节点上的多个元素关联同一个表的情况
SqlTable associatedSqlTable = base.FindSqlTable(association.ID, sql.SqlBuildingInfo);
if (associatedSqlTable == null)
{
var assoTableName = context.DataObjectTableMapping[association.AssoDomainObject.DataObject.ID];
associatedSqlTable = base.TryFindAndRegistSqlTable(association.AssoDomainObject.DataObject.ID, assoTableName, assoTableName, assoTableName, sql.SqlBuildingInfo);
}
var childAssociation = new InternalAssociation()
{
AssociatedCommonObject = association.AssoDomaiModel,
AssociatedCoNode = association.AssoDomainObject,
AssociatedDataObject = association.AssoDomainObject.DataObject,
AssociatedTable = associatedSqlTable,
LocatedCommonObject = sql.SqlBuildingInfo.CommonObject,
LocatedDataObject = sql.SqlBuildingInfo.CurrentDataObject,
LocatedNode = sql.SqlBuildingInfo.CurrentNode,
LocatedTable = sql.SqlBuildingInfo.CurrentSqlTable,
Association = association,
AdditionalCondition = association.FilterCondition
};
foreach (var refElement in association.RefElements)
{
var element = association.AssoDomainObject.Elements.FirstOrDefault(i => i.ID == refElement.ElementID);
var assElement = new InternalRefElement()
{
Element = element,
Label = element.Alias
};
childAssociation.RefElements.Add(assElement);
}
BuildLeftJoin(sql, childAssociation, context);
}
private string ParseCondition(InternalAssociation association)
{
return association.Association.FilterCondition;
}
