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The primary key and foreign key are the adhesives that organize multiple tables into a valid relational database. The primary key and foreign key design have a decisive impact on the performance and availability of the physical database. The database mode must be converted from the logical design to the physical design

The primary key task is to help MySQL determine the location of a specific data record in the data table as quickly as possible. The primary key must meet the following two conditions: 1. The primary key must be unique. The primary key fields in any two data records cannot be the same. 2. The primary

The primary key and foreign key are the adhesives that organize multiple tables into a valid relational database. The primary key and foreign key design have a decisive impact on the performance and availability of the physical database. The database mode must be converted from the logical design to the physical design

Simple tutorial on SQL statements in linux --- primary key, foreign key, and SQL Primary Key)Each item in is a unique value in the table. In other words, it is used to uniquely identify each row of data in a table. A primary key can be a column in the original data, or a column created by a person (a column irrelevant

MySQL primary key auto-generated table design MySQL has many primary key generation strategies, and one of the most common is auto-generated. In general, the primary key type is bigint UNSIGNED, and the keyword that automatically generates the primary key is auto_increment.CREATE TABLE Stock (id BIGINT UNSIGNED NOT nul

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

Mac OS X keyboard logo, shortcut key, switch operation key, screenshot capture tool Mac keyboard logo explanation ------------------------------------------------- (Command key)-on some Apple keyboards, this key may also contain the Apple logo () control Key) (Option

Rotten mud: Learning ssh key portable, ssh key This article is written by Xiuyi Lin FengProviding friendship sponsorship, first launched in the dark world In the previous article, "Learn ssh without password", we explained how to use an ssh key to log on to the server without a password. This article explains how to carry generated keys with you. For detailed

SSH key to use the non-symmetric encryption RSA algorithm, about the RSA algorithm, the following blog has a detailed description:Http://www.ruanyifeng.com/blog/2013/06/rsa_algorithm_part_one.htmlHere are just a few key points to describe the creation of the secret key: Randomly select two large prime numbers p and Q,p is not equal to Q, calculate N=PQ.

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

Liu Weihan-Learning pastryLinks: http://www.zhihu.com/question/25912483/answer/31653639Source: KnowCopyright belongs to the author. Commercial reprint please contact the author for authorization, non-commercial reprint please specify the source.Let's review RSA's cryptographic algorithms. Based on the definition of public key cryptography and signature algorithms, we describe this algorithm in a more canonical language.RSA public

The Redis key command is used to manage Redis keys.GrammarThe basic syntax for the Redis Key command is as follows:Redis 127.0.0.1:6379> COMMAND Key_nameInstanceRedis 127.0.0.1:6379> SET w3ckey redisokredis 127.0.0.1:6379> DEL w3ckey (integer) 1 In the above instance DEL is a command, W3ckey is a key. If the key is del

Method One: Use Puttygen.exeThe first step: Creating a secret key Run Puttygen.exe, select the key type and length you want, use the default SSH2 (RSA), and set the length to 1024. Passphrase can be empty so that you don't have to enter a password at logon. Click the Save private Key button to save the public key an

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

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IDEA shortcut key, idea shortcut key 1. Ctrl Shortcut Key Introduction Ctrl + F Search for text in the current file(Required) Ctrl + R Replace text in the current file(Required) Ctrl + Z Undo(Required) Ctrl + Y Delete the row where the cursor is located or delete the selected row(Required) C

How does MySQL solve the unique primary key duplicate value during the insertion process? mysql primary key This article describes how to avoid DUPLICATE keys when inserting data into a table. It mainly involves IGNORE, on duplicate key update, and REPLACE; next, let's take a look at the three solutions. IGNORE Ignore is used to automatically ignore duplicate rec

In this paper, the implementation method of RSA algorithm based on private key encryption public key decryption is described, and it is a widely used algorithm. Share it for everyone's reference. Here's how:I. OverviewThe RSA algorithm is the first algorithm that can be used for both encryption and digital signatures, and is easy to understand and manipulate. RSA is the most widely researched public-