Entities in the body, reactions of consciousness and methods of working with them. Entity types Any entity that is different from other entities

Then, it is possible that forced cleansing and removal of various kinds of entities can not only ease the vibrations of the bodies, but sometimes, under severe stress, increase the risk of injury to the soul. So, you need to take everything off yourself carefully, and it is better to seek an understanding of rejection of something or feel how low-frequency vibrations are formed, for example, with any humiliation of you, or turn on your intuition or scanner and avoid low-frequency sources.

Better yet, find why the body rejects this or that vibration and, when the muscles are compressed, forms a congestion or block, and teach the body not to be afraid of such attacks and to accept these vibrations consciously, understanding that they are not produced by you. The body or cells do not have flexible thinking and accept everything as it is, for them the incoming vibration is perceived as their own and this gives them a signal that something is wrong with them, and a false alignment process begins, and this means excess energy goes away and fatigue and complete blackout.

Understanding your body at the level of cells and the vibrations they emit is not so difficult.

Well, here's an example. When humiliated, you simultaneously become an observer and observe how the body reacts to it and then, you will quickly begin to understand what fear is and how it is formed from what kind of vibrations. It’s just that the cells have their own harmony, their own rhythm at which they emit a signal, the so-called personal biorhythms, tuned to the rhythm of the Source’s plan. If I get offended, angry or try to humiliate someone, in order to get what I want from another, to force the other to do as I want, this disrupts the harmony of cells, changes their vibration frequency.

Then the consciousness of the cells, programmed to equalize its biorhythm, through some chemical processes, restores the necessary vibration, at which the cells are comfortable, and a lot of energy is spent on this. And also, if we receive aggression in the ray of someone else’s attention, it also changes this comfortable vibration. If you teach the body at the vibration level to recognize where it is and where it is someone else’s, the cells simply will not respond to someone else’s signal, protection is automatically created, by increasing vibrations and the signal or quantum of consciousness returns back to the owner.

We can use different ones, but they still simply transfer the cells into their harmonious range of vibrations, where they are not attuned to the aggression of others. This is probably why we get fat, because our cells store up a source of additional energy in case of stress.

You can also harmonize yourself through so-called pure vibrations. You begin to generate vibration from your magnetic torus, for example, deep respect, tenderness or honesty and sincerity, or crystal transparent vibrations. I myself, empirically, through sensitivity, looked for such vibrations. For example, tenderness, only it is not directed specifically at someone and is not glued to the action, like help because of some of your beliefs, sometimes false, but you just, like the sun, sit and generate them into space, as if for everyone and not for anyone in particular. You are totally at this moment all of this. And then the cells, when you teach them this, they themselves begin to create it and live in this radiation.

Another interesting practice in communicating with other people is this:

Before starting communication, be it with the director of a company, a minibus driver, a salesperson in a store or a loved one, in our minds we evoke positive images or qualities inherent in the interlocutor (for example, he is kind, handsome, wise, etc.). In this way, we tune in to positive communication and form the appropriate vibration for the field of events.

Addition:
I wrote here about generation, but very intelligent beings came and drew my attention to the difference between generating and simply radiating without violence. this awareness came up in the dialogue...

From the dialogue about radiation and generation:

There is such a deep vibration - dignity. You just freeze for a moment, at this moment there is no effort, you just exist, everything external is discarded, as if at this moment it is very easy for you. There is no desire to generate something by force, at such a moment you simply exist as you are. And from this internal state you give yourself a request to radiate dignity. Not even a request, you just remember these impulses, also without effort. There is a difference in simple radiation from within and generation. When generating, you make an effort and enter into movement. Usually we generate during communication, but you radiate with yourself completely. There is no movement, you seem to have frozen, stopped and radiate yourself, without any effort at all. Try this and feel the difference...

Look, you yourself wrote just now, you want to approach him through tenderness and something good, you generate it, make an effort, use these vibrations as a tool, but there is no satisfaction. You know why, you gave and are waiting in return too. And when you simply radiate, you are just a source of the sun, you have no goal of getting anything from your effort.

Resentment is precisely what is created precisely from the fact that for your expended effort, for your generation, for example, the quality of tenderness, you were not given anything at all or were given the wrong thing. And when there is no expectation, there is no effort, there is no resentment that you spent money, and in response, nothing or nothing. But if you radiate, you can do it, whatever you want to receive, putting the right filter on the right thought. For example, “I Want” replace “I Am” with this and radiate it effortlessly, then if you don’t receive it from someone else, you will live it within yourself, and if these signals also go into space, they will begin to attract it...

2.3. Entity classification

Three classes of entities

The time has come to understand the terminology. K.Date [ 3 ] defines three main classes of entities: rod, associative And characteristic, as well as a subclass of associative entities – designations.

Core essence (core)

Core Essence (kernel) is an independent entity (it will be defined in more detail below).

In the examples discussed earlier, the rods are “Student”, “Apartment”, “Men”, “Doctor”, “Marriage” (from example 2.2) and others, whose names are placed in rectangles.

Associative entity (association)

Associative Entity (association) is a many-to-many (1-to-many, etc.) relationship between two or more entities or instances of an entity (as in example 2.4). Associations are treated as full-fledged entities:

they can participate in other associations and designations just like core entities;

may have properties, i.e. have not only a set of key attributes necessary to indicate relationships, but also any number of other attributes that characterize the relationship.

For example, associations "Marriage" from examples 2.1 And 2.4 contain the key attributes "Code_M", "Code_Zh" and "Husband's Personnel Number", "Wife's Personnel Number", as well as clarifying attributes "Certificate Number", "Registration Date", "Registration_Place", "Registration Number in the Civil Registry Office Book", etc. .d.

Characteristic entity (characteristic)

Characteristic entity (characteristic) is a many-to-one or one-to-one relationship between two entities (a special case of association). The sole purpose of a characteristic within the subject area under consideration is to describe or clarify some other entity. The need for them arises due to the fact that entities of the real world sometimes have multi-valued properties. A husband can have several wives (example 2.3), a book can have several characteristics of a reprint (corrected, expanded, revised, ...), etc.

The existence of a characteristic depends entirely on the entity being characterized: women lose their status as wives if their husband dies.

To describe the characteristic, a new JIM proposal is used, which in general has the form:

CHARACTERISTIC (attribute 1, attribute 2, ...)

(LIST OF CHARACTERIZED ENTITIES).

Let's also expand the language of ER diagrams by introducing a trapezoid to represent the characteristics (Fig. 2.2).

Rice. 2.2. Elements of the extended ER diagram language

Designating entity or designation

Designating entity or designation is a “many-to-one” or “one-to-one” relationship between two entities and differs from a characteristic in that it does not depend on the designated entity.

Example

Let's consider an example related to the enrollment of employees in various departments of the organization.

In the absence of strict rules (an employee can be simultaneously enrolled in several departments or not be enrolled in any department), it is necessary to create a description with the association Enrollment:

Employees (Personnel number, Last name, ...)

Enrollment [Departments M, Employees N]

(Department number, Personnel number, Date of enrollment).

However, provided that each employee must be enrolled in one of the departments, you can create a description with the designation Employees:

Departments (Department number, Department name, ...)

Employees (Personnel number, Last name, ..., Department number,

Date of enrollment)[Departments]

In this example, the employees have an independent existence (if a department is deleted, it does not follow that the employees of that department should also be deleted). Therefore, they cannot be characteristics of departments and are called designations.

Notations are used to store repeating values ​​of large text attributes: “codifiers” of disciplines studied by students, names of organizations and their departments, lists of goods, etc.

The description of a designation differs externally from the description of a characteristic only in that the designated entities are enclosed not in curly brackets, but in square brackets:

NOTE (attribute 1, attribute 2, ...)[LIST

DESIGNATED ENTITIES].

Typically, designations are not treated as full entities, although this would not lead to any error.

Designations and characteristics are not completely independent entities, since they presuppose the existence of some other entity that will be “designated” or “characterized.” However, they still represent special cases of an entity and can, of course, have properties, can participate in associations, designations and have their own (lower level) characteristics. We also emphasize that all instances of a characteristic must be associated with some instance of the characterized entity. However, it is allowed that some instances of the characterized entity do not have relationships. True, if this concerns marriages, then the essence of “Husbands” should be replaced by the essence of “Men” (there is no husband without a wife).

Let us now redefine the core entity as an entity that is neither an association, nor a designation, nor a characteristic. Such entities have independent existence, although they can designate other entities, such as employees designate departments.

In conclusion, let us consider an example of constructing an information model of the “Nutrition” database, where information about dishes (Fig. 2.3), their daily consumption, the products from which these dishes are prepared, and the suppliers of these products should be stored. The information will be used by the chef and manager of a small catering establishment, as well as its visitors.

Rice. 2.3. Example of a recipe

With the help of these users, the following objects and characteristics of the designed base were identified:

Dishes that require data included in their culinary recipes to describe: dish number (for example, from a book of culinary recipes), name of the dish, type of dish (appetizer, soup, main course, etc.), recipe (technology for preparing the dish), yield (portion weight), name, calorie content and weight of each product included in the dish.

For each product supplier: name, address, name of product supplied, delivery date and price at the time of delivery.

Daily food consumption (consumption): dish, number of servings, date.

Analysis of objects allows us to highlight:

stems Dishes, Products and Cities;

associations Composition (links Dishes with Products) and

Supplies (links Suppliers with Products);

designation Suppliers;

characteristics Recipes and Consumption.

The ER diagram of the model is shown in Fig. 2.4. and the model in the YAM language has the following form:

Dishes (BL, Dish, View)

Products (PR, Product, Calorie content)

Suppliers (POS, City, Supplier) [City]

Composition [Dishes M, Products N] (BL, PR, Weight (g))

Supplies [Suppliers M, Products N] (POS, PR, Date_P, Price, Weight (kg))

Cities (City, Country)

Recipes (BL, Recipe) (Dishes)

Consumption (BL, Date_R, Portions) (Dishes)

In these models, Dish, Product and Supplier are names, and BL, PR and POS are digital codes of dishes, products and organizations supplying these products.

Rice. 2.4. Infological model of the "Nutrition" database

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2.4. About primary and foreign keys

Let us recall that key or possible clue is a minimum set of attributes whose values ​​can be used to unambiguously find the required instance of an entity. Minimality means that excluding any attribute from the set does not allow the entity to be identified by the remaining ones. Every entity has at least one possible key. One of them is taken as primary key. When choosing a primary key, you should give preference to non-composite keys or keys made up of a minimum number of attributes. It is also inappropriate to use keys with long text values ​​(integer attributes are preferable). Thus, to identify a student, you can use either a unique record book number, or a set of last name, first name, patronymic, group number and possibly additional attributes, since it is possible that two students (and more often female students) with the same last names, first names and patronymics. It is also bad to use as a key not the number of the dish, but its name, for example, “Appetizer of processed cheese “Friendship” with ham and pickled cucumber” or “Hare in sour cream with potato croquettes and red cabbage salad.”

The primary key of a core entity (any attribute participating in the primary key) is not allowed to have an undefined value. Otherwise, a contradictory situation will arise: a non-individual, and therefore non-existent, instance of the core essence will appear. For the same reasons, it is necessary to ensure uniqueness primary key.

Now about foreign keys:

If entity C links entities A and B, then it must include foreign keys corresponding to the primary keys of entities A and B.

If entity B refers to entity A, then it must include a foreign key corresponding to entity A's primary key.

In p. 2.3 An example was considered where "Employees" stood for "Departments" and included a foreign key "Department Number" corresponding to the primary key of the "Departments" entity.

The relationship between primary and foreign keys of entities is illustrated in Fig. 2.5.

Rice. 2.5. Structures: a - associations; b - designations (characteristics)

Here, to designate any of the associated entities (cores, characteristics, designations or even associations), a new generalizing term “Goal” or “Target Entity” is used.

Thus, when considering the problem of choosing how to represent associations and notations in a database, the main question that needs to be answered is: “What are foreign keys?” And then, for each foreign key, three questions need to be resolved:

1. Can this foreign key accept undefined values ​​(NULL values)? In other words, can there be some instance of an entity of a given type for which the target entity indicated by the foreign key is unknown? In the case of supplies, this is probably not possible - a supply from an unknown supplier or a supply of an unknown product does not make sense. But in the case of employees, such a situation could however make sense - it is quite possible that any employee is not currently enrolled in any department at all. Note that the answer to this question does not depend on the whim of the database designer, but is determined by the actual course of action adopted in that part of the real world that is to be represented in the database in question. Similar remarks are relevant to the issues discussed below.

2. What should happen when you try to DELETE a target entity that is referenced by a foreign key? For example, when deleting a supplier who has made at least one delivery. There are three possibilities:

3. What should happen when you try to UPDATE the primary key of a target entity that is referenced by some foreign key? For example, an attempt may be made to update the number of a supplier for which there is at least one corresponding delivery. For clarity, we will again consider this case in more detail. You have the same three options as when deleting:

CASCADES	The update operation is "cascaded" to also update the foreign key in that provider's supplies.
LIMITED.	The primary keys of only those suppliers who have not yet made deliveries are updated. Otherwise, the update operation is rejected.
INSTALLED	For all deliveries of that supplier, the NULL value of the foreign key is set to undefined, and then the supplier's primary key is updated. This feature, of course, is not applicable if the foreign key must not contain NULL values.

Thus, for each foreign key in a design, the database designer must specify not only the field or combination of fields that makes up that foreign key and the target table that is identified by that key, but also the answers to the above three questions (the three constraints that apply to this foreign key).

Finally, about characteristics - denoting entities, the existence of which depends on the type of denoted entities. The designation is represented by a foreign key in the table corresponding to that characteristic. But the three foreign key constraints discussed above for this case should be specified as follows:

NULL values ​​are not allowed

REMOVAL FROM (target) CASCADES

UPDATE (target primary key) CASCADES

The specified specifications represent dependence on the existence of characteristic entities.

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2.5. Integrity Constraints

Data Integrity Concept

Integrity(from the English integrity - intactness, inviolability, safety, integrity) - is understood as the correctness of data at any time. But this goal can only be achieved within certain limits: the DBMS cannot control the correctness of every single value entered into the database (although each value can be checked for plausibility). For example, it cannot be discovered that the input value 5 (representing the day of the week) should actually be 3. On the other hand, the value 9 would clearly be an error and should be rejected by the DBMS. However, to do this, she should be told that the numbers of the days of the week must belong to the set (1,2,3,4,5,6,7).

Maintaining database integrity can be thought of as protecting data from unauthorized changes or destruction (not to be confused with unauthorized changes and destruction, which are a security issue). Modern DBMSs have a number of means to ensure that integrity is maintained (as well as means to ensure that security is maintained).

Types of integrity

There are three groups of integrity rules:

Entity integrity.

User-defined integrity.

In p. 2.4 The motivation for two integrity rules common to any relational databases was considered.

Any attribute participating in a primary key is not allowed to have an undefined value.

The foreign key value must either:

be equal to the value of the target's primary key;

be completely uncertain, i.e. Each attribute value participating in a foreign key must be null.

For any specific database, there are a number of additional specific rules that apply to it alone and are determined by the developer. Most often controlled:

the uniqueness of certain attributes,

range of values ​​(exam score from 2 to 5),

belonging to a set of values ​​(gender "M" or "F").

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2.6. About building an information model

Introduction

A reader who has become acquainted only with the material in this and the previous chapters will not be able to correctly perceive and evaluate the tips and recommendations for building a good information model, which have been developed over decades by the largest specialists in the field of data processing. To do this, you need to at least study the following materials. Ideally, it is necessary for the reader to first implement at least one information system project, offer it to real users, and be a database and application administrator long enough to realize at least a small fraction of the problems that arise from an insufficiently thought-out design. The experience of the author and all the information systems specialists he knows shows that any theoretical recommendations are taken seriously only after several unsuccessful attempts to revive poorly designed systems. (Although there are also designers who continue to believe that they can revive a dying project by changing programs, rather than by changing the database infological model.)

Requirements for the database from the administrator and application programmer

Indeed, to determine the list and structure of stored data, it is necessary to collect information about real and potential applications, as well as about database users, and when building an information model, you should only care about the reliability of storing this data, completely forgetting about the applications and users for which the database is being created data.

This is due to the completely different requirements for the database of application programmers and the database administrator. The former would like to have in one place (for example, in one table) all the data they need to implement a request from an application program or from a terminal. The latter take care of eliminating possible distortions of stored data when entering new information into the database and updating or deleting existing information. To do this, they remove duplicates and unwanted functional relationships between attributes from the database, breaking the database into many small tables (see paragraph. 4.6 ). Since many years of global experience in using information systems built on the basis of databases shows that design flaws cannot be eliminated by any tricks in application programs, experienced designers do not allow themselves to meet application programmers halfway (even when they themselves are such).

clearly distinguish between such concepts as requesting data and maintaining data (entering, changing and deleting);

remember that, as a rule, a database is the information basis of not one, but several applications, some of which will appear in the future;

a bad database design cannot be corrected by any (even the most sophisticated) applications.

Goal of the work– get acquainted with the basic concepts of infological database modeling, learn to describe models using information modeling languages.

BASIC CONCEPTS

The purpose of information-logical (infological) modeling is to provide the most natural ways for humans to collect and present information that is supposed to be stored in the database being created.

Infological data model is a generalized informal description of the database being created, made using natural language, mathematical formulas, tables, graphs and other tools that are understandable to all people working on database design. It is a human-centric model that is completely independent of the physical parameters of the data storage environment.

The main constructive elements of information models are entities, connections between them and their properties (attributes).

Essence– any distinguishable object (an object that we can distinguish from another), information about which must be stored in a database. Entities can be people, planes, flights, color, taste, etc.

Entity type it is a collection of homogeneous persons, objects, events or ideas acting as a whole. For example, the entity type could be CITY,CAR.

Entity instance – this is a specific item in the set. For example, an instance of an entity will be Moscow, Kyiv, Zhiguli, Moskvich, etc.

Attribute – a named characteristic of an entity. Its name must be unique for a specific entity type, but can be the same for different entity types.

For example, COLOR can be defined for many entities: DOG, CAR, SMOKE, etc.

Attributes are used to define what information should be collected about an entity. Examples of attributes for the CAR entity are Type, Make, License Plate, Color, etc.

Here too there is a distinction between type and instance. The Color attribute type has many instances or values: Red, Blue, etc., but each entity instance is assigned only one attribute value.

Absolute difference between entity types and attributes absent. An attribute is such only in relation to the entity type. In another context, an attribute may act as an independent entity. For example, for an automobile plant, COLOR is only an attribute of the production product, but for a paint and varnish factory, COLOR is an entity type.

Key - a minimum set of attributes whose values ​​can be used to uniquely find the required instance of an entity. Minimality means that excluding any attribute from the set does not allow the entity to be identified by the remaining ones. For example, for the SCHEDULE entity, the key is the attributeFlight number or set:Departure point, Departure time, Destination (provided that one plane flies from point to point at any given time).

Connection - association of two or more entities.

There are three main classes of entities: core, associative and characteristic, as well as a subclass of entities - designations.

Core essence (core) – it is an independent entity that is neither an association, nor a designation, nor a characteristic. Such entities have independent existence, although they can designate other entities.

Associative entity (association) – is a many-to-many relationship between two or more entities or instances of an entity. Associations are considered as full-fledged entities, they can participate in other associations and designations in the same way as core entities; have properties, that is, have not only a set of key attributes necessary to indicate relationships, but also any number of other attributes that characterize the relationship.

Characteristic essence (characteristic) - this is a “many-to-one” or “one-to-one” connection between two entities (a special case of association). The only one target characteristics within the subject area under consideration consists in describing or refining some other entity. The need for them arises due to the fact that entities of the real world have multi-valued properties.

For example, a book may have several reprint characteristics (expanded, revised, etc.), a husband may have several wives, etc.

The existence of a characteristic depends entirely on the entity being characterized: women lose their status as wives if their husband dies.

Designating entity (designation) is a “many-to-one” or “one-to-one” relationship between two entities and is different from the characteristic in that it does not depend on the designated entity. Notations are used to store repeating values ​​of large text attributes: “codifiers” of disciplines studied by students, names of organizations and their departments, lists of goods, etc.

As a rule, the designations are not considered as full-fledged entities, although this would not result in any error. Designations and characteristics are not completely independent entities, since they presuppose the existence of some other entity that will be “designated” or “characterized.” However, they still represent special cases of an entity and can, of course, have properties, can participate in associations, designations and have their own (lower level) characteristics. It should be noted that all instances of a characteristic must be associated with some instance of the characterized entity. However, it is allowed that some instances of the characterized entity do not have relationships.

If the purpose of the database was only to store individual, unrelated data, then its structure could be very simple. However, one of the main requirements for organizing a database is ensuring the possibility of finding some entities by the values ​​of others, for which it is necessary to establish certain connections between them. And since real databases often contain hundreds or even thousands of entities, theoretically more than a million connections can be established between them. The presence of such a multitude of connections determines the complexity of information models.

Language for constructing information models. When building information models, you can use the ER language - diagrams(from the English Entity-Relationship, that is, an entity is a connection), which is used to build small models and illustrate individual fragments of large models, and information modeling language (IML), more meaningful, but less visual in which entities and associations are presented in the form of sentences.

In ER diagrams essence are depicted (Table 1) marked with rectangles,associations– marked with diamonds or hexagons,attributes –marked with ovals, A communications between them - non-directional ribs(lines connecting geometric shapes), above which the degree of connection (1 or a letter replacing the word “many”) and the necessary explanation can be indicated.

In the information modeling language (IML), entities and associations are represented by sentences of the form:

ENTITY (attribute 1, attribute 2, ..., attribute n);

ASSOCIATION [ENTITY S1, ENTITY S2, ...]

(attribute 1, attribute 2, ..., attribute n);

where S is the degree of connection, and the attributes included in the key must be marked with an underline;

CHARACTERISTIC (attribute 1, attribute 2, ...)

(LIST OF CHARACTERIZED ENTITIES). DESIGNATION (attribute 1, attribute 2, ...)

[LIST OF DESIGNATED ENTITIES].

Table 1. Elements of languages ​​of the infological model

		Entity classes
		Rod (kernel)	Associative (association)	Characterizing (characteristic)	Denoting (designation)
ER - diagram
	(…, … )	[…, …, …, … ]		{..., …, … }	[…, …, … ]

Types of connections. The following types of relationships are possible between two entities:

The first type is the relationship ONE - TO - ONE (1:1); at each moment of time, each instance of entity A corresponds to 1 or 0 representatives of entities B.

The second type is the connection ONE - TO - MANY (1: M); One representative of entity A corresponds to 0.1 or several representatives of entity B.

Since connections in both directions are possible between two entities, there are two more types of connections: MANY - TO - ONE (M: 1) and MANY - TO - MANY (M: N). In addition, there are more complex connections (APPENDIX 1):

Many connections between the same entities;

Training connections;

Connections of higher orders, semantics (meaning), which are sometimes very complex.

Primary and foreign keys. Every entity has at least one possible key. One of them is taken as primary key. When choosing a primary key, you should give preference non-composite keys or keys composed of a minimum number of attributes. Inappropriate also use keys with long text values ​​(it is preferable to use integer attributes). Not allowed, so that the primary key of the core entity (any attribute participating in the primary key) takes on an undefined value. Otherwise, a contradictory situation arises: a non-individual and, therefore, non-existent instance of the core essence will appear. For the same reasons, it is necessary to ensure uniqueness primary key.

If entity C links entities A and B, then it must include foreign keys, corresponding to the primary keys of entities A and B.

If entity B stands for entity A, then it must include external key, corresponding to the primary key of entity A.

The relationship between primary and foreign keys of entities is shown in Fig. 1.

Rice. 1. Structures: a – associations; c – designations; (characteristics)

1. Define entities.

2. Identify connections between entities.

3. Depict the infological model of the subject area in the form of an ER diagram and using NIM.

Note: Options for assignments are provided to teachers.

SELF-TEST QUESTIONS

Define an infological data model; essences; entity type; entity instance; attribute; communications.

name the main structural elements of information models.

Name the classes and subclasses of entities.

Describe the core; associative; characteristic; denoting entities.

name one of the main requirements for organizing a database.

What languages ​​can be used to build information models?

For which models is the ER diagram language used?

What figures represent the main structural elements of ER diagrams?

In what form are the main structural elements of the NRM presented? Give an example.

What types of relationships are possible between entities?

What is the difference between primary and foreign keys?

What is the relationship between primary and foreign keys of entities?

Annex 1

Table P1. Examples of describing the connections of an information model in different languages

	ER diagrams
		Marriage (certificate number, husband's last name, husband's first name, husband's date of birth, place of registration, etc.)
		Marriage (certificate number, Code M, Wife's last name, Registration date) (Wives)
		Marriage (certificate number, M code, wife’s full name, registration date) (Husbands)
		Marriage (certificate number, Code M, code Zh, wife’s full name,) (Husbands, Wives) Husbands (code M, full name, date of birth, place of birth) Wives (code F, full name, date of birth, place of birth)

Appendix 2. example of building an information model for the “Nutrition” database

The “Nutrition” database should store information about dishes (Fig. P 2.2), their daily consumption, the products from which these dishes are prepared, and the suppliers of these products. The information will be used by the chef and manager of a small catering establishment, as well as its visitors.

With the help of these users, the following objects and characteristics of the designed base were identified:

1. Dishes for which the description requires data included in their culinary recipes: dish number (for example, from a book of culinary recipes), name of the dish, type of dish (appetizer, soup, main course), recipe (technology for preparing the dish), yield (portion weight ), name, calorie content and weight of each product included in the dish.

2. For each product supplier: name, address, name of product supplied, delivery date and price at the time of delivery.

3. Daily food consumption (consumption): dish, number of servings, date

Analysis of objects allows us to highlight:

Rods Dishes, Products, Cities;

Associations Composition (links dishes with Products) and

Supplies (links Suppliers with Products);

Designation Suppliers;

Characteristics Recipes and Consumption.

ER– the diagram is shown in the figure

M

products

N

M 1

The database model IN the YAM language has the following form: Dishes (BL, Dish, Type), Products (PR, Product, Calorie), Suppliers (POS, City, Supplier), Ingredients [Dishes M, Products N] (BL, PR, Weight (d)) Supplies [Suppliers M, Products N] (POS, PR, Date P, Price, Weight (kg))

Living in a three-dimensional world, we rarely notice the work of beings from other dimensions. And even religion does not deny their presence. Do you know what astral entities are? How and why do they come to a person? Why are they harmful and how to protect yourself from them? Would you say that this is fiction? Such naive confidence will quickly disappear as soon as you interest astral entities in something. Their types are so diverse that it is quite difficult to understand the results of their activities. Let's figure out what they are and why people are afraid of them.

General concept

There are several theories regarding these objects unknown to the common man. Drunvalo Melchizedek wrote that they represent inhabitants who came to our world by chance. Astral entities live by their own rules. They do not know human laws. However, the people themselves are interesting. The fact is that we differ from other inhabitants of the vast Universe in that we know how to generate energy. Our guests eat it. Everything is very simple. They themselves are not able to get food from space. But by definition, any person is very good at it. He is designed in such a way that his body and soul function in two streams, on which, like a bead on a string, he “dangles” in space. Man continuously receives and processes the energy of the Universe and the Earth. We feel it as feelings, thoughts, emotions. Astral entities attach themselves to the aura and take away part of this incredible wealth. But clean energy does not suit them. These creatures feed on low-frequency energy. In our understanding - evil, hatred, resentment, doubt, and so on.

What do entities do to a person?

You are probably familiar with the term “possessed.” It is applied to a person who, under certain circumstances, exhibits inappropriate behavior. The priests say he is possessed by demons. These astral entities (the photos make me horrified) have settled in the aura of the unfortunate man. His will is partially or completely suppressed. They are led by beings from another world. They provoke a person to do strange things. They need the unfortunate person to experience negative emotions himself and force others to do the same. The energy emitted by a human being is not suitable for demons. They are truly afraid of the bright side of personality. That’s why they try to push a person to sin. Possession is an extreme case.

Subtle bodies of man and essence

To understand the topic, here is a diagram. Imagine that a person is a ball filled with air. This is how the aura is often depicted schematically. This ball has two inputs and outputs, through which energy constantly flows in and out. Its average quantity is such that the volume remains unchanged. The contents of the ball are exactly what the entities are after. But they will not be able to attach themselves to a tightly stretched shell. This happens when the person is happy and satisfied. If a person often has negative thoughts, he gets angry, offended, grumbling, indignant, envious, suffering (then list it yourself, based on experience), then the elasticity of the shell decreases. Or, in other words, dark spots appear in the aura. It is very easy for entities to get to these places and gain a foothold on them.

It is worth understanding that there are quite a lot of these around us. Everyone hunts for their own type of negative energy. If you, for example, are prone to jealousy, a larva will stick to you and begin to provoke exactly this feeling. She will also call a friend who “feeds” on guilt. Together they push towards a glass. If you don’t resist, the larva of alcoholism will also appear in your aura. And they will throw a mountain feast on your energy, taking away the strength that is given to organize a happy life. The person himself will transform them into negative ones in order to feed his unwanted neighbors.

Astral entities: types

We have listed the most common astral entities. Their classification, according to esoteric theory, is much broader. But even from the examples given, it will be possible to get a general idea of ​​the methods of their work and the level of harm caused to humans. Let's look at each in more detail.

Lyarva

Incubi and succubi

Photos of these objects sometimes appear in various sources. The authenticity of these images is difficult to judge. In any case, experts call most of them fakes. In principle, the point is not in the photographs. Demons are the source of many misfortunes. They pull a large number of people into the funnel of inferno (negative energy), forcing them to kill and die. But the demon cannot possess the first person it meets. He needs a suitable energy space for life. And it is created by the person himself with negative, destructive, dangerous thoughts and actions. They say about such people: they have lost their conscience. But astral entities are most afraid of pure energy. They are afraid of divine, which means love that does not depend on anything. They do not move in with people in whose aura it is present.

Elementors

At the moment of death, the soul is freed from the human body and sent to the astral plane. But there are exceptions. Sometimes, due to attachment, due to magical influence, or for other reasons, the soul does not want (or does not have the opportunity) to fly into the space that the Lord has allocated for its existence. She inhabits the aura of her loved one. Elementera cannot be called a negative entity in the literal sense. It exists due to the energy of living things, slightly weakening its field. However, it does not provoke him into destructive activity. He is not afraid of pure energies. In addition, thanks to its connection with the Universe, the elementer is able to protect the person who has accepted it from worldly dangers. However, this condition is not considered natural. The entity is not able to go to the subtle worlds and cannot independently leave the carrier’s aura. She loses the chance for a new incarnation, which is very bad for her personal destiny and for the entire family.

Astral entities: classification according to L. G. Puchko

• A lying spirit forces its victim to lie. A person becomes depressed and loses touch with reality. As a rule, a lying spirit attaches itself to those who suffer from any addiction (gaming, alcohol, drugs). This unfortunate man constantly, aimlessly, senselessly lies.
• Lucifer penetrates the victim's aura during the full moon. It pushes a person to unreasonable harsh aggression. A person cannot restrain his impulses. He argues with everyone, makes scandals, and is capable of violence, including sexual violence.
• Archimania is an entity that chooses stingy people. The victim strives to have as much as possible of what he considers valuable.
• UFOs appear in people obsessed with contact with aliens.
• A nerve blocker causes a person to suffer from pain.
• A leech is an alien energy structure that attaches itself to people with a low vibration level. The victim quickly gets tired, becomes irritable, and often gets sick.
• The shell forces the personality to abandon naturalness. A person puts on a mask and becomes false, like a bad actor.
• A witch is an entity created by a sorcerer. It is meaningful and aimed at getting the victim to behave in a certain way. A kind of negative energy information program, popularly called corruption.

It should be noted that L. G. Puchko focused on harm to human health, highlighting the types of astral entities. They also have a negative effect on memory. The fact is that these formations take energy from the victim, forcing him to experience hunger, which is extremely harmful to his body and brain.

In addition, it is recommended to change your diet. It is not in vain that there are fasts in any religion. Restrictions in the sphere of physical pleasures help cleanse the energy. Naturally, first of all it is necessary to give up all bad habits.

It should be noted that not all entities can be dealt with independently. Sometimes you should trust a specialist. Thus, the astral essence of a person (elementary) will not leave the aura as a result of prayers and diet. It should be removed with a special ritual. To combat the most common entities, they chastise them with prayers, sometimes in church. Those who are possessed are treated in monasteries. You can deal with weak entities yourself. You should clear your thoughts and get rid of negative emotions. That is, fill your entire field with light energy. There are special techniques of multidimensional medicine that help to quickly cope with the problem. They consist in the fact that the patient is asked to read the vibration series.

Prevention

Where there is attention, there is power! Strive to direct it towards love. This does not mean a feeling that brings a man and a woman together for procreation. Love can be divine. This is a state of ideal happiness, when everyone is happy, nothing makes you angry or irritates. The soul of every person strives for him. Although this is impossible on earth. Only an angel manages to be in a state similar to the ideal. But this does not mean that a person does not have the right to strive for divine love. Even intention will already isolate most of the entities from you. They will not be able to receive anything, therefore, they will lose interest in your aura. In fact, the world is very harmonious. Astral entities are drawn to those who themselves create satisfactory conditions for them. Why waste energy so mediocrely? What do you think?

An entity is a physical representation of a logical grouping of objects called instances.

An entity is a subject, place, thing, event or concept that contains information. Entities can be tangible, real objects such as a CLIENT or a CLOSET, or intangible conceptual abstractions like a COST CENTER or THOUGHT. Entities are not intended to represent a single entity, but rather a collection of instances containing information of interest in terms of their uniqueness. For example, the CLIENT entity is an instance of objects of the Client type. Ivan Ivanov and Savely Kramorov are specific examples of instances of the CLIENT entity. A specific instance of an entity is represented by a table row and is identified by a primary key.

The entity has the following characteristics:

· It has a name and description.

· It represents a class, not a single instance of an abstraction.

· Its specific representatives (instances) can be uniquely identified.

· It contains a logical grouping of attributes that represent information of interest to the corporation

In ER model diagrams, an entity is represented as a rectangle containing the name of the entity. In this case, the name of the entity is the name of the type, not a specific object. Each instance of an entity must be distinguishable from every other instance of the same entity.

The entity must be referred to as a singular noun and written in capital letters.

An entity in IDEF1X describes a collection or set of instances that are similar in properties, but clearly distinguishable from each other by one or more characteristics. Each instance is an implementation of an entity. Thus, an entity in IDEF1X describes a specific set of real-world instances. An example of an IDEF1X entity could be the “EMPLOYEE” entity, which represents all employees of the enterprise, and one of them, say, Petr Sergeevich Ivanov, is a specific implementation of this entity.

Both dependent and independent entities can be divided into the following types:

· Core entities - these are sometimes called core or primary entities. They represent important objects about which information should be stored.

· Associative Entities – These entities are used to resolve many-to-many relationships.

· Characteristic entities – these entities are of two types: exclusive and inclusive.

Core entities represent the most important corporate information objects. These are sometimes called primary, main, or core entities. Because these entities are extremely important, they are likely used in many parts of the corporation. Take the time to look for similar entities, as core entities are likely to be reusable. Within a corporation, core entities must be modeled consistently. Good modelers view this approach as extremely useful.

Core entities can be either independent or dependent. For example, for a corporation that sells televisions, the TELEVISION entity represents the corporation's base product. The STORE entity is an example of a distribution channel or intermediary for the sale of goods. Although the example may seem a bit straightforward, it illustrates the power of the concept behind core entity modeling.

Understanding the need to model core entities as scalable and extensible containers requires the modeler to view entities as abstract concepts and model information independent of the current way it is used. In this example, the TV entity model is completely outside the context of the STORE entity and vice versa. So if a corporation decides to sell a TV through a new distribution channel, such as the Internet or home delivery, the new distribution channel can be added without changes to other entities.

Code entities are always independent. They are often called references, classifiers, or entity types, depending on the methodology used. The unique instances represented by code entities define the scope of attribute values ​​belonging to other entities. The relationships between code entities and other entities will be discussed in a future post on this topic. You may be tempted to use a single attribute in the code table. It is much better to include at least three attributes in the encoding entity: identifier, name (sometimes called short name), and definition.

Code entities usually contain a limited number of attributes. There are implementations where these entities only had one attribute. It is preferable to model encoding entities using a surrogate key.

Professionals often refer to code entities as corporate business objects. The term enterprise business object indicates that the entity is defined and shared at the enterprise level rather than at the level of a single application, system, or organizational unit. These entities are often shared between multiple databases to provide a holistic approach to summary reporting and trend analysis.

Associative entities are entities that contain the primary keys of two or more other entities. Associative entities are always dependent. They are used to resolve many-to-many relationships between other entities. A many-to-many relationship occurs when multiple instances of one entity are associated with multiple instances of another. Associative entities allow us to model the intersection of instances of two entities, ensuring that each association instance is unique.

Many-to-many relationships cannot be implemented in a database at the physical level. ERwin automatically creates associative entities to resolve many-to-many relationships when moving from a logical model to a physical model.

A naming entity is a special case of an associative entity that has no attributes of its own (only the attributes of parent entities that migrated as a foreign key).

Characteristic entities are always dependent. You should use characteristic entities where it makes sense for entity instances to store different sets of attributes. Finklestein calls characteristic entities secondary entities. Characteristic entities always have one or more “peer” entities. Peer characteristic entities are related to a parent entity by a special type of relationship that can be exclusive or inclusive.

Peer characteristic entities that are in an exclusive relationship to a parent entity indicate that only one of the peer entities contains an instance for any of the instances of the parent entity. The exclusive characteristic entity represents the "is a" relation.

For example, an insurance company has full-time office employees (administrators) and agents who have more flexible work schedules and pay. From their common properties, a generalized entity (generic ancestor) Employee can be formed to represent information common to all types of employees. Information specific to each type can be located in the categorical entities (descendants) “Permanent Employee” and “Agent”.

Please note that the EMPLOYEE instance must be an ADMINISTRATOR or AGENT. An EMPLOYEE cannot be both an ADMINISTRATOR and an AGENT. These are exclusionary characteristic entities.

Note that exclusive characteristic entities will not allow one instance of EMPLOYEE to contain facts that are common to ADMINISTRATOR and AGENT. This may be contrary to actual practice. The ADMINISTRATOR can also act as an AGENT. This is an example of inclusive characteristic entities.

A type of characteristic entity is a categorical entity. A categorical entity is a child entity in the inheritance hierarchy of a characteristic entity. An inheritance hierarchy (or category hierarchy) is a special type of grouping of entities that share common characteristics.

Typically, an inheritance hierarchy is created when several entities have attributes that are common in meaning, or when entities have connections that are common in meaning (for example, if “PERMANENT EMPLOYEE” and “PARTITIONER” had a similar in meaning connection “works in” with the COMPANY entity), or when business rules dictate it.

Category hierarchies are divided into two types: complete and incomplete. In a full category, one instance of a generic ancestor (Employee entity, Fig. A1) necessarily corresponds to an instance in some descendant, i.e. in the example, the Employee is necessarily either an Administrator or an Agent.

Rice. P2. Inheritance hierarchy: incomplete category

· click first on the generic ancestor, and then on the descendant;

· to establish a second relationship in the category hierarchy, first click on the category symbol, then on the second child.

To edit categories, right-click on the category symbol and select Subtype Relationship Editor from the context menu. In the Subtype Relationship dialog, you can specify the discriminator attribute of the category (Discriminator Attribute Choice list) and the category type - complete/incomplete (Complete/Incomplete radio buttons).

Structural entity. Sometimes instances of the same entity are related. In K. Finklestein's book Strategic Systems Development, he proposed using structural entities to represent relationships between instances of the same entity. Relationships between instances of the same entity are called recursive relationships. Recursive relationships will be discussed in the article “The Concept of a Relationship.” Recursive relationships are a logical concept, and the concepts are not easily understood by users.

In Fig. P3 shows an additional structural entity that describes the relationship between instances of the EMPLOYEE entity.

The diagram models the subordination relationships between employees of any complexity. Since the subordination relationship always connects two people, two identifying links are established from the Employee entity to the subordination relationship entity with the names of the roles “Manager” and “Subordinate”. Each employee can be in a supervising/subordinate relationship with any other employee, but the same pair of employees can share the same type of subordination relationship. The Subordination Relationship entity represents the relationship between instances of the EMPLOYEE entity.

Rice. P3. Structural entity.

Related information.