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MySQL foreign key details, MySQL key details Recently, when I was studying Hibernate, I was always confused by foreign keys. Moreover, my MySQL foreign key learning is not very solid, so in order to better master Hibernate and MySQL, therefore, I searched for some blogs on the Internet to learn how to create Foreign keys and add Foreign keys for MySQL. I had a de

Set MySQL data table primary key: Use the "PRIMARY key" keyword to create a primary key data column. The primary key column is set to not allow duplicate values, in many cases combined with "auto_increment" incrementing numbers. As shown in the following SQL statement:To modify a column primary

Symmetric key encryption in HTTPS, public key encryption, digital certificate keyWe call unencrypted content plaintext, and the encrypted content is called ciphertext.In short, to encrypt a piece of plaintext, you can enter this content into an encryption function, output ciphertext. However, this simple encryption method has been stolen into the cryptographic function to crack the danger of clear text, and

Today saw a bit about the public key encryption of the content, quickly write down the province's forgotten.Here are a few concepts: public key, private key, encryption, authentication, authentication Center (CA), digital certificate.Public and private keys are asymmetric encryption, and the public and private keys are completely different, but correspond to each

Encryption and authenticationFirst, we need to distinguish the two basic concepts of encryption and authentication.Encryption encrypts data so that illegal users cannot obtain the correct data even if they have obtained the encrypted data. Therefore, data encryption can protect data and prevent attacks. The focus is on data security. Identity Authentication is used to determine the authenticity of an identity. After the identity is confirmed, the system can grant different permissions according

Encryption and authenticationFirst, we need to distinguish the two basic concepts of encryption and authentication.Encryption encrypts data so that illegal users cannot obtain the correct data even if they have obtained the encrypted data. Therefore, data encryption can protect data and prevent attacks. The focus is on data security. Identity Authentication is used to determine the authenticity of an identity. After the identity is confirmed, the system can grant different permissions according

Primary key: There are several attributes in the record, and if one of the attribute groups (note is a group) can uniquely identify a record, the attribute group can become a primary key;PRIMARY key //primary keyYour foreign key is the primary key of the other table so joi

This article references Http://www.cnblogs.com/jimshen/archive/2009/11/09/1599347.html Http://blog.csdn.net/allwtg/archive/2009/12/09/4969543.aspx Concepts of public and private keys In modern cryptographic systems, encryption and decryption use different keys (public keys), that is, public keys.Algorithm(Also called asymmetric algorithms and two-key algorithms) ", each communication party requires two keys, namely, the public

The Redis key (Key) command command describes the Redis DEL command, which is used to delete key in key presence. The Redis Dump command serializes the given key and returns the serialized value. The Redis EXISTS command checks to see if a given

Label:The role of the primary and foreign keys of sql: Foreign key value rule: A null value or a reference primary key value. (1) When a non-null value is inserted, it cannot be inserted if the value is not in the primary key table. (2) When updating, you cannot change the value that is not in the primary key table. (3

Key-Value Pair storage (1): What is key-Value Pair Storage? Why? Author: Emmanuel Goossaert Original article: codecapsule.com In this article, I will begin with a short description of what a key-value pair is. Then I will explain some reasons for this project, and finally I will explain the main objectives of the key-

Redis key Space Notification (KEYSPACE notification) This document is translated from: Http://redis.io/topics/notifications. The key space notification feature is still under development, and the content described in this document, as well as the specific implementation of the functionality, may change over the next few weeks, please be informed. Features Overview A key