Question

需要一个解决方案来查看网格文件是否存在，然后使用元数据更新文件。

我正在使用以下解决方案。但想要更好的一个。

不介意使用单独的Update和Delete方法。

谢谢

Public Class storedXYZ 

    Property Data As Stream

    Property MetaData As storedXYZMetaData

End Class

Public Sub SaveStoredXYZ(storedXYZ As StoredXYZ) 


        Dim MongoGridFSCreateOptions As New MongoDB.Driver.GridFS.MongoGridFSCreateOptions

        Dim qry As IMongoQuery


        qry = Query.EQ("metadata.StoredXYZId", BsonValue.Create(storedXYZ.MetaData.StoredXYZ.ToString()))


        Dim gridFile As MongoGridFSFileInfo = mdbGridFS.FindOne(qry)


        If gridFile IsNot Nothing Then

            Dim mongoStream As MongoGridFSStream

            MongoGridFSCreateOptions.Metadata = storedXYZ.MetaData.ToBsonDocument

            mongoStream = gridFile.OpenWrite()

            ''Convert MongoStream to MemoryStream
            Dim fs As Stream = New MemoryStream()
            Dim buffer As Byte() = New Byte(9999) {}
            Dim bytesRead As Integer = 0
            Do
                bytesRead = storedXYZ.Data.Read(buffer, 0, buffer.Length)
                mongoStream.Write(buffer, 0, bytesRead)
            Loop While bytesRead > 0

            mongoStream.Seek(0, SeekOrigin.Begin)
            mongoStream.Position = 0


            mdbGridFS.SetMetadata(gridFile, storedAXYZ.MetaData.ToBsonDocument)

        Else

            MongoGridFSCreateOptions.Metadata = storedXYZ.MetaData.ToBsonDocument

            Dim fileinfo As MongoGridFSFileInfo

            fileinfo = mdbGridFS.Upload(storedXYZ.Data, storedXYZ.MetaData.Name, MongoGridFSCreateOptions)

        End If

End Sub

Answer 1

而不是试图覆盖当前文件，为什么不只是触发删除命令，然后重新上传文件并将文档更新为旧文件？

Answer 2

当您使用现有文件名上传文件时，MongoGridFS上传方法会获取该文件的新版本。

将OpenWrite与现有文件名一起使用可以更新文件。 C＃驱动程序是唯一允许更新GridFS文件的驱动程序。

More information here

Answer 3

您可以将fs.files和fs.chnuks集合用作任何其他集合，但您必须小心保持GridFS数据的重要性不受影响。

MongoDB C＃如何更新GridFS文件和元数据？

3 个答案: