Question

我正在尝试将图像存储在我的sqlite数据库中作为BLOB数据类型，然后在我的网页上显示图像，但我不断收到sqlalchemy错误（我使用sqlalchemy作为我的ORM），错误：

sqlalchemy.exc.StatementError
StatementError: buffer object expected (original cause: TypeError: buffer object expected) u'INSERT INTO room (owner_name, size, description, price, address, owner_number, room_image, university_id) VALUES (?, ?, ?, ?, ?, ?, ?, ?)' [{'owner_name': u'Thomas Jefferson', 'description': u'Master Bedroom, Non-furnished, toilet attached', 'price': u'RM650/Month', 'room_image': <FileStorage: u'udacity.png' ('image/png')>, 'university_id': 1, 'address': u'Cyber Heights Villa', 'size': u'325sqft', 'owner_number': u'+60111223456'}]

以下是我的代码： 1.）我的数据库设置文件（我在房间表中有BLOB列）：

import sys
from sqlalchemy.dialects.sqlite import BLOB
from sqlalchemy import Column, ForeignKey, Integer, String
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from sqlalchemy import create_engine
Base = declarative_base()


class University(Base):

    __tablename__ = "university"

    #column definitions for the university table
    id = Column(Integer, primary_key=True)
    name = Column(String(250), nullable=False)
    city = Column(String(80), nullable=False)

    @property
    def serialize(self):
        #Returns object data in easilty serializable format
        return{
            "name": self.name,
            "city": self.city,
            "id": self.id,
        }


class Room(Base):

    __tablename__ = "room"

    #column definitions for the room table
    owner_name = Column(String(90), nullable=False)
    id = Column(Integer, primary_key=True)
    size = Column(String(60))
    description = Column(String(250))
    price = Column(String(10))
    address = Column(String(250))
    owner_number = Column(String(15))
    room_image = Column(BLOB)
    university_id = Column(Integer, ForeignKey("university.id"))
    university = relationship(University)

engine = create_engine("sqlite:///gotroom.db")
Base.metadata.create_all(engine)

2。）这是我的python文件代码，我打算允许将图像作为BLOB上传到room_image中（在newRoom函数中，照片图像的上传将发生并存储在我的房间表中的room_image列中）：

#show rooms for a university
@app.route("/university/<int:university_id>/")
@app.route("/university/<int:university_id>/rooms/")
def showRooms(university_id):
    university = session.query(University).filter_by(id=university_id).one()
    rooms = session.query(Room).filter_by(university_id=university_id).all()
    return render_template("rooms.html", rooms=rooms, university=university)


#create a new room for a particular university
@app.route("/university/<int:university_id>/rooms/new/", methods=["GET", "POST"])
def newRoom(university_id):
    if request.method == "POST":
        aNewRoom = Room(owner_name=request.form["ownerName"], size=request.form["roomSize"]\
                       , description=request.form["roomDescription"], price=request.form["roomPrice"]\
                        , address=request.form["adress"], owner_number=request.form["phoneNum"], \
                        room_image=request.files["roomImage"], university_id=university_id)

        session.add(aNewRoom)
        session.commit()

        #feedback to user
        flash("New Room Created")       

        return redirect(url_for("showRooms", university_id=university_id))
    else:
        return render_template("newroom.html", university_id=university_id)

3。）这里是用于创建新房间的表单模板代码＆＃34; newroom.html＆＃34; （我必须允许上传图片）：

<form action="{{url_for('newRoom', university_id=university_id)}}" method="POST" enctype='multipart/form-data'>
    <div class="row">
        <div class="col-md-4">
            <input type="text" class="form-control" name="ownerName" placeholder="Name">
        </div>

        <div class="col-md-3">
            <input type="text" class="form-control" name="phoneNum" placeholder="Contact Number">
        </div>

        <div class="col-md-5">
            <input type="text" class="form-control" name="adress" placeholder="Address">
        </div>
    </div><!--first row-->
    </br>
    <div class="row">
        <div class="col-md-2">
            <input type="text" class="form-control" name="roomSize" placeholder="Room Size">
        </div>

        <div class="col-md-2">
            <input type="text" class="form-control" name="roomPrice" placeholder="Room Price/Month">
        </div>
    </div><!--second row-->
    </br>
    <div class="row">
        <div class="col-md-4" style="height: 100px">
            <input type="text" class="form-control" name="roomDescription" placeholder="Room Details" style="height: 100%">
        </div>
        <input type='file' name='roomImage'>
    </div>
    </br>

    <input type="submit" value="Post Room" class="btn btn-success btn-lg" role="button">

</form>

4。）这里是模板代码，我想显示所有信息，包括图像：

        </br>

        <img src="{{room.room_image}}">
        <strong>Owner Name</strong>: {{room.owner_name}}

        </br>
        <strong>Contact Number</strong>: {{room.owner_number}}
        </br>
        <strong>Home Address</strong> : {{room.address}}
        </br>
        <strong>Room Price</strong> : {{room.price}}
        </br>
        <strong>Room Size</strong>  : {{room.size}}
        </br>
        <strong>Room Description</strong>: {{room.description}}
        <div>

任何时候我删除图像，我都没有收到错误，但是一旦我尝试显示图像，错误就会再次出现，有什么可以帮我解决这个问题吗？我可以根据需要提供更多细节或代码

Answer 1

从错误中看来，您正试图传递错误的类型。我相信BLOB期待一个二进制文件，而你传递的是png。您可以使用make_blob()方法将图像转换为二进制文件。查看this页面，它应该会有所帮助。

Python（烧瓶）BLOB图像，SQLite，Sqlalchemy - 显示图像

1 个答案: