private void DeleteMiddles(DomainObject obj)
{
var middles = RootIsSlaveIndex.Get(this);
foreach (var middle in middles)
{
middle.DeleteMiddleByRootSlave(obj);
}
}
/// <summary>
///
/// </summary>
/// <param name="master"></param>
/// <param name="slave"></param>
/// <param name="memberField"></param>
/// <returns></returns>
private static DataTable CreateMiddleTable(DataTable slave, IDataField memberField)
{
var root = slave.Root;
var master = slave.Master;
string tableName = string.Format("{0}_{1}", master.Name, memberField.Name);
IDataField[] fields = null;
var objectType = (memberField as ObjectField).GetReflectedType(); //就算集合的成员类型各自不同，但是他们肯定继承至同一个根类，因此中间表是统一一个类型的
if (root.IsEqualsOrDerivedOrInherited(master))
{
var rootField = GetForeignKey(master, GeneratedFieldType.RootKey, DbFieldType.NonclusteredIndex);
var slaveField = GetForeignKey(slave, GeneratedFieldType.SlaveKey, DbFieldType.NonclusteredIndex);
slaveField.ParentMemberField = memberField;
var indexField = GeneratedField.CreateOrderIndex(objectType, DbFieldType.NonclusteredIndex);
//注意，大多数查询都是以rootField 为条件, indexField为排序，输出slaveField字段，
//所以slaveField的位置在最后
fields = new IDataField[] { rootField, indexField, slaveField };
}
else
{
var rootField = GetForeignKey(root, GeneratedFieldType.RootKey, DbFieldType.NonclusteredIndex); //中间表中追加根字段，可以有效防止数据重叠
var masterField = GetForeignKey(master, GeneratedFieldType.MasterKey, DbFieldType.NonclusteredIndex);
var slaveField = GetForeignKey(slave, GeneratedFieldType.SlaveKey, DbFieldType.NonclusteredIndex);
slaveField.ParentMemberField = memberField;
var indexField = GeneratedField.CreateOrderIndex(objectType, DbFieldType.NonclusteredIndex);
//注意，大多数查询都是以rootField, masterField为条件, indexField为排序，输出slaveField字段，
//所以slaveField的位置在最后
fields = new IDataField[] { rootField, masterField, indexField, slaveField };
}
var middle = DataTable.CreateMiddle(root,
master,
tableName,
DataTableType.Middle,
fields,
memberField);
middle.Slave = slave;
//如果从表是根，那么需要记录从表和中间表的联系，当删除根对象时，会删除该中间表的数据
RootIsSlaveIndex.TryAdd(middle);
return(middle);
}
