What does spiritual dependence mean?
Mental dependence, also known as psychological dependence, refers to the feeling of pleasure and satisfaction after repeated contact with something (such as after taking drugs, or being attracted by certain characteristics of others in interpersonal relationships, etc.), which leads to a strong desire for continuous contact with that thing in the mind, which then leads to the behavior of forcing people to seek that thing in order to obtain satisfaction and avoid discomfort. This kind of dependence is an excessive dependence on a specific object or activity, which may have a negative impact on an individual's life. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
Ordinary Dependence and Extraordinary Dependence
Ordinary dependence refers to the dependence of a certain attribute set on itself in the relationship. For example, in a set composed of attributes A and B, the dependence of A and B on themselves (A→A and B→B) is trivial dependence. In a table that stores student performance information, the set of attributes {SNo, CNo, Score},{SNo} → SNo,{CNo, Score} → Score, etc. are also trivial dependence. Nontrivial dependence is if X → Y holds and Y does not belong to X. For example, in a student's report card,{SNo, CNo} → Score is a non-trivial dependence because Score does not belong to the combination key {SNo, CNo}. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
What does non-trivial functional dependence mean?
Let a relation be R(U), and X and Y be the sets of attributes U. If X→Y and X does not contain Y, then X→Y is called a non-trivial functional dependence. For example, in employee relations, the employee number function determines every other attribute (such as employee number determines salary), which is a non-trivial functional dependence. In addition, for example,"(employee number, name) → gender", although the employee number attribute may be enough to determine the gender, this situation is also a non-trivial functional dependence. It was different from ordinary functional dependence. Ordinary functional dependence was that if X contained Y, then X→Y must exist.(For example, the employee number could always be determined by the function itself, that is,"employee number → employee number", or the attribute set composed of employee number and gender could always determine the employee number or gender attribute, such as "(employee number, gender) → employee number" and "(employee number, gender) → gender".) Usually, the main topic was non-trivial functional dependence. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
Is ordinary dependence the same as extraordinary dependence?
Ordinary dependence was different from extraordinary dependence. A trivial dependence refers to a property or property set that is completely dependent on itself. For example, in the relationship R(A, B), A -> A and B -> B are trivial dependence. The non-ordinary dependence was not the dependence of this attribute collection on oneself. In the process of database normalisation, trivial dependence had no practical effect and would not affect the integrity or integrity of the database design. It was more used to define and identify more complex dependence relationships, such as functional dependence, partial dependence, and transitive dependence. Non-trivial dependence had different effects and meanings in the design of the database. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
The difference between ordinary dependence and extraordinary dependence
Ordinary Dependence referred to the fact that a certain attribute in the attribute set depended on itself and did not need to obtain information from other attributes. For example, in a table containing the property set {SNo, CNo, Score},{SNo} → SNo, {CNo, Score} → Score is a trivial dependence. A non-trivial dependence is a non-trivial dependence if X → Y is true and Y does not belong to X. For example, in the student report,{SNo, CNo} → Score is a non-trivial dependence, because the score Score does not belong to the combination key {SNo, CNo}. In summary, the main difference between the two was that ordinary dependence was the dependence of attributes on themselves, while non-ordinary dependence was the dependence of an attribute (set) on another attribute (set) that did not belong to itself. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
trivial functional dependence and partial functional dependence
Based on context alone 1. ** Ordinary Function Dependence ** - In a database, let R(U) be a relation pattern on a set of attributes U, and X and Y be a set of attributes U. If Y is a sub-set of X (that is, Y X), then X→Y is a trivial functional dependence. - For example, in the relationship mode of students (student number, name, gender),{student number, name}→{name} is a trivial functional dependence, because the name itself is a part of {student number, name}. Semantically speaking, trivial functional dependence represented an obviously established dependence relationship. This dependence relationship did not actually contain much meaningful new information, because it only indicated that the dependence of a set of attributes on its own set must exist. 2. ** Part of Function Dependence ** - Let (X,Y) be the property set of the relation pattern (R). If (X→Y) exists a proper set of (X ') such that (X'→Y), then (Y) is partially dependent on (X). - For example, in the Relational Mode course selection (student number, course number, grades, course name),{student number, course number}→{course name}, but in fact,{course number}→{course name}, which meant that the course name only depended on the student number and the course number in the course number, not the entire {student number, course number}, so the course name was partially dependent on {student number, course number}. Partial functional dependence may cause data redundancy-like problems. In the standardized design of a database, it is usually necessary to eliminate partial functional dependence to achieve a higher standard. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
Is ordinary multi-valued dependence a functional dependence?
Function dependence and multi-valued dependence were different types of data dependence. Ordinary multi-valued dependence was not a functional dependence. The functional dependence reflected the relationship between attributes or attribute groups. When one attribute set determined another attribute set, the other attribute set was said to be dependent on the attribute set. Multi-valued dependence was within the definition of 4nf, which was much more complicated than functional dependence. In functional dependence, whether X and Y had a functional dependence only needed to examine the two sets of attributes of X and Y, and had nothing to do with other attributes. In multi-valued dependence, whether X and Y had a multi-valued dependence depended on attribute Z. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
Dependence, is it love?
Dependence and liking were two different concepts. The sense of dependence was produced when one's own value relationship was restricted by the value relationship of others. It was more reflected in the hope that the other party would continue to pay attention to oneself and accompany oneself when one was tired and bored. It was a feeling of relying on others. Liking someone was usually established between two independent personalities. It was more about having a good impression or interest in someone or something. It was a relatively positive emotion. For example, one wanted to share their happiness with the other party. They did not only need the other party's company when they were sad. Therefore, dependence was not like.
Non-trivial functional dependence and trivial functional dependence
Let X and Y be the attributes of a relation, and X→Y. If Y is contained in X, then X→Y is called a trivial functional dependence. If Y is not contained in X, then X→Y is called a non-trivial functional dependence. The trivial functional dependence was automatically established because it was determined by the reflexive nature of the functional dependence. The functional dependence that was generally studied was mostly non-trivial functional dependence. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
Non-trivial functional dependence and complete functional dependence
Non-trivial functional dependence: In the Relational Model, if there is an attribute set X and an attribute set Y, and X→Y, but Y is not a sub-set of X, this functional dependence is called a non-trivial functional dependence. For example, in the relationship between students (student number, name, class, course, grade), student number → grade was a non-trivial functional dependence, because grades were not a sub-set of student number, and the student number could determine the attribute of grades. Complete functional dependence: In a relationship, if a non-main attribute data item depends on all keywords, it is called complete functional dependence. For example, in the relationship course selection (student number, course number, score), the score was completely dependent on the combination of the student number and course number. This was because the student number or course number alone could not determine the score. Only the combination of the two could determine the score. The Extraordinary Ordinary Life novel is equally exciting. Everyone is welcome to click and read it!
Long-term dependence
Changxiang Yi's simplified musical scores could be found on many websites, such as the music website, the Chinese music website, and the music website. This song's simplified musical score was in the key of G, and it could also be in 2nd grade. In addition, there were also some related articles and recommendations that could be used as reference.