key grabber

This article mainly introduces the specific definition and usefulness of super-key, candidate key, primary key, main attribute, foreign key in MySQL database. You can also refer to the topic.alibabacloud.com MySQL video tutorial and MySQL manual。 First look at the definitions of the various keys: Super

Primary Key and foreign key in the database, primary key of the database 1. What are primary keys and Foreign keys: A record in a relational database has several attributes. If one of the attribute groups (note that it is a group) uniquely identifies a record, the attribute group can become a primary key, for example:

one, key and primary key differenceCREATE TABLE Wh_logrecord (logrecord_id Int (one) not NULL auto_increment,User_name varchar (+) default NULL,Operation_time datetime default NULL,Logrecord_operation varchar (+) default NULL,PRIMARY KEY (logrecord_id),KEY Wh_logrecord_user_name (USER_NAME))Analytical:KEY Wh_logrecord_

Internet Key Exchange (IKE)Before exchanging data between two IPSec computers, a convention must be established first, a convention called a "security association", in which both parties need to agree on how to protect the information, exchange information, and other common security settings, and more importantly, there must be a way for the two computers to securely exchange a set of keys. For use in their connections. See figure Seven. Figure VII, I

Key:I understand the public key + private key collectively. Key pair:The Public key (certificate) and private key are in pairs. Each side of the communication holds its own private key and the other's public

Internet Key Exchange (IKE)Before the two IPSec computers exchange data, they must first establish an agreement called "Security Association ", both parties need to reach an agreement on how to protect information, exchange information, and other public security settings. More importantly, there must be a way for the two computers to securely exchange a set of keys, for use in their connections. See Figure 7.Figure 7 Internet

First, 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 to different identities. The

There is a multi-dimensional array, which can be customized. If we want to find a subIndex value in this array, we can use methods such as for and foreach to traverse and find the reverse. If we give one or more keys at will, you must find the keys and values of the parent-level array of the key. How can this be achieved? There is a multi-dimensional array, which can be customized. If we want to find a value with the

In general, the current SaaS service provides the current SDK or API docking service that involves an authentication and data encryption issue. It is generally common practice to configure the use of asymmetric encryption to solve this problem, you hold the public key of the SaaS company, the SaaS company holds your public key, you can do encryption and signature verification.Let's look at two ways to gener

I think so:Traverse multi-dimensional arrays and create an index for all keys to generate a one-dimensional array;Check the upper-level array and data of the key by using the key name each time.OK. The Code is as follows:IndexKey:Copy codeThe Code is as follows:/*** FILE_NAME: arr. php FILE_PATH: test/* Quick query of the parent key and parent

In mysql, key, primary key, unique key and index are different, mysqlunique Indexes in mysql are very important knowledge points. Compared with other knowledge points, indexes are more difficult to master, and there are many index types in mysql, such as primary key, unique key