(max_length=200) price = models.DecimalField(max_digits=8,decimal_places=2) date_available = models.DateField() orders = models.ManyToManyField(Order,through='LineItem')
Then, you can directly find the order containing the product through the product object:
$ python manage.py shell>>> from depot.depotapp.models import Product>>> p = Product(id=1)>>> p.orders>>> p.orders.all()[, ]
The purpose of this relationship is to generate a "subscription
Liferea is a desktop subscription software that is easy to use. The latest version of the software Liferea 1.10.8 has been released, which is a patch fix version.
It is very easy to install using PPA. The supported system versions include Ubuntu 14.04, 13.10, 12.10, 12.04, Linux Mint 17, 16, 14, 13, and Elementary OS 0.2.
Open the terminal and enter the following command:
Sudo add-apt-repository ppa: ubuntuhandbook1/appsSudo apt-get updateSudo ap
Hello:
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The command on the slave2 host is:
#kafka-console-consumer.sh--zookeepermaster:2181--topictest--from-beginning
The result is as follows:
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This article is from
Background:Recently, a publishing subscription always reports a delay at night. Because the copy backup occupies the bandwidth at night and no one uses the subscribed data at night, it has never been viewed, recently, I went up and looked at it and found many problems. The server has 12 GB of memory and 16 CPUs.
Troubleshooting steps and solutions:1. view the current large number of pageiolatch_sh wait information, the execution is the distribution o
I. Introduction of the Scene
A recent project needs to use the Publish/Subscribe information system to inform the latest real-time messages. After finding out that Redis pub/sub (information system for publish/subscribe) can meet my development needs, and the cost of learning and use is also relatively low.
Two. What is Redis pub/sub
Data View
Everyone is watching my blog at the same time can open the Redis official Redis pub/sub Introduction, feel the English document difficult to read
, yo
", "headimgurl": "http://wx.qlogo.cn/mmopen/utpKYf69VAbCRDRlbUsPsdQN38DoibCkrU6SAMCSNx558eTaLVM8PyM6jlEGzOrH67hyZibIZPXu4BK1XNWzSXB3Cs4qpBBg18/0", "subscribe_time": 1375726425, "unionid": "oTBn-jt2RQSHdBoJQYFSdnZo8BBQ "}Iv. Significance of unionid
For enterprises with multiple accounts, unionid can help identify whether users under different public accounts are the same person. In this way, the services provided to the user under different accounts can be continuously increased.
You can also rem
I am using the Redis is installed on the native virtual machine, the use of Java connection encountered some errors, summed up the need to change the place as follows:1, redis configuration file by default is bound 127.0.0.1 IP, need to find this line in redis.conf, comment out2, Redis default does not allow non-native Client connection, itself is no password, need to set a login password, connect with a passwordSet password command: Config set Requirepass xxx, after the password settings need t
' [x] b ' Info:hello world! [x] B ' Info:hello world! One ' [x] b ' Info:hello world! [x] B ' Info:hello world! [x] B ' Info:hello world! [x] B ' Info:hello world! [x] B ' Info:hello world! [x] B ' Info:hello world! [x] B ' Info:hello world! [x] B ' Info:hello world! 19 ' You can see that the message received by two subscribers is the same.The status change for each subscriber does not affect the message received by another subscriber.Third, queue informationOn the Web Administration page, view
::multithreadedspinner spinner (2); Use 2 threadsSpinner.spin (); Spin () won't return until the node has been shutdownUse Multithreadedspinner to indicate that this node has two threads, also available (Boost::thread), and that the desired functionality is finally implemented, but because the for loop is faster and no lock is used, the stop is sent every time, Exiting the For loop is not the same level, so you need to think about it.[1] http://wiki.ros.org/roscpp/Overview/Callbacks%20and%20Spin
Label:Remote subscriptions rely on the Distributed Transaction Coordinator service, which requires access to the server's 135 port and requires that the publisher and the subscriber's MSDTC be opened ( Start-Control Panel-Administrative Tools-Component Services-computers-My Computer-distributed Transaction coordinator-local DTC), check security-local DTC, allow remote clients, allow remote administration, allow inbound, allow to play, do not authenticateSQL SERVER2008
1. As shown in the picture, we will see the red box icon after opening the YY soft, then we click on "Discovery Channel" to enter.
2. When we open the Discovery Channel, we will see a "Activity center" which we click on:
3. In the Activity Center we find the rightmost button with an asterisk icon, as shown in the following illustration:
4. All right, we'll get to the next page and we'll see all our subscriptions.
Friendly tips, this is my use of the latest version of YY to see
1 basicPublish/Subscribe is a message communication pattern. Instead of publishing messages to subscribers, publishers publish to different channels. Subscribers accept messages of the channel they are interested in and do not need to contact the publisher.Sub/pub are both client, and channel is server., the message is sent to the three sub client when the new message is posted to Channel1 via the Publish command.2 commandsSubscribe to a channel on the CLI: Channel1127.0.0.1:6379> SUBSCRIBE chan
The first part is quoted in: Click to open1: Brief IntroductionPub-sub mode is not generally processed by the system's key data. The Publisher does not care if the Subscriber receives the published message, nor does the subscriber know if he or she has received all the messages from the publisher. You also don't know when subscribers start receiving messages. Similar to broadcasting, radio. So logically, it's not reliable. This can be solved by combining with the request response model.Figure 1:
This blog post mainly introduces the implementation of the simple chat room from the following two parts:1. Introduction to Redis Publish subscription mode2.java Code Implementation Subscription Publishing mode
One, Redis Publish subscription modeRedis subscriptions are divided into subscription channels and
A few days ago, I participated in a learning and exchange group of agile individuals organized by Zhou jingen. Some people in the group discussed Google Reader's usage skills. More people do not know what Google Reader is. I wrote a blog here to share my skills in using Google Reader and the technology subscription source provided by instructor Zhou jingen. Some of the resources in this article come from the Internet.
1. Google Reader
Google Re
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