//1 找到状态为"initial"的事务文档
private TransactionDocumentP RetrieveTransaction()
{
FilterDefinitionBuilder <TransactionDocumentP> filterBuilder = Builders <TransactionDocumentP> .Filter;
FilterDefinition <TransactionDocumentP> filter = filterBuilder.Eq(doc => doc.State, "initial");
return(mongoDBService.Single(TransactionCollectionName, filter));
}
/// <summary>
/// 查找某一个子文档
///</summary>
public void QueryChild()
{
FilterDefinitionBuilder <Model2> filterBuilder = Builders <Model2> .Filter;
//找到父文档，过滤条件为Field2A=2并且Field2B=“2018-01-21T16:00:00.000Z”
FilterDefinition <Model2> filterFather = filterBuilder.Eq(doc => doc.Field2A, "2")
& filterBuilder.Eq(doc => doc.Field2B, DateTime.Parse("2018-01-21T16:00:00.000Z"));
//投影定义创建器：ProjectionDefinitionBuilder
//用ProjectionDefinition过滤子文档,投影器创建器作用于Field2C，他是一个集合，用来保存多个子文档；过滤条件为Field1C = 3.1415926
ProjectionDefinitionBuilder <Model2> projBuilder = Builders <Model2> .Projection;
ProjectionDefinition <Model2> proj = projBuilder.ElemMatch(listField => listField.Field2C, childfield => childfield.Field1C == 3.1415926);
FindOptions options = new FindOptions()
{
AllowPartialResults = true
};
Model2 info = mongoDBService.Single <Model2>(collectionName, filterFather, options, proj);
}