MindMap Gallery Access database
Access database has super comprehensive study notes. Database technology is an important part of modern information science and technology. Department of Computer Data Processing and Information Management the core of the system.
Edited at 2024-02-10 20:14:12This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
This is a mind map about Deep Analysis of Character Relationships in Zootopia 2, Main content: 1、 Multi-layer network of relationships: interweaving of main lines, branch lines, and hidden interactions, 2、 Motivation for Character Behavior: Active Promoter and Hidden Intendant, 3、 Key points of interaction: logic of conflict, collaboration, and covert support, 4、 Fun Easter eggs: metaphorical details hidden in interactions.
This article discusses the Easter eggs and homages in Zootopia 2 that you may have discovered. The main content includes: character and archetype Easter eggs, cinematic universe crossover Easter eggs, animal ecology and behavior references, symbol and metaphor Easter eggs, social satire and brand allusions, and emotional storylines and sequel foreshadowing.
[Zootopia Character Relationship Chart] The idealistic rabbit police officer Judy and the cynical fox conman Nick form a charmingly contrasting duo, rising from street hustlers to become Zootopia police officers!
This is a mind map about Deep Analysis of Character Relationships in Zootopia 2, Main content: 1、 Multi-layer network of relationships: interweaving of main lines, branch lines, and hidden interactions, 2、 Motivation for Character Behavior: Active Promoter and Hidden Intendant, 3、 Key points of interaction: logic of conflict, collaboration, and covert support, 4、 Fun Easter eggs: metaphorical details hidden in interactions.
Access database
basic concept
Database technology is an important part of modern information science and technology and the core of computer data processing and information management systems.
The form of data can be numbers, text, graphics or sounds, etc.
Characteristics of data management in the manual management stage: data is not saved; is not shared; data needs to be managed by the application itself; there is basically no concept of files during this period, and the organization of data must be designed by programmers themselves
Characteristics of data management in the file management stage: data can be saved for a long time; has a certain degree of independence; is managed by the file system; the forms of data files have been diversified
The characteristics of data management in the database system stage: provide users with a convenient user interface; provide data control functions; have high data independence; use data models to represent complex data structures
Database system features
Data structuring
data sharing
Controllable redundancy (data is not repeated)
Have high data independence
Unified management and control
Database management system serves as the interface between users and databases
Operations on data do not necessarily have to be performed in units of records, but can also be performed in units of data items, which increases the flexibility of the system.
Database management system functions
data definition
Data operations
Database operation management
Database creation and maintenance functions
Database architecture
external level
concept level
internal level
One-to-one correspondence data model
conceptual model
logical data model
physical data model
The relational data model, referred to as the relational model, consists of three parts: data structure, relational operations, and relational integrity.
A relationship corresponds to a two-dimensional table
The minimum attribute or set of attributes that can uniquely identify a row in a table is called the primary key.
In a relational database, in order to realize the connection between tables, the main key of one table is placed in another table as the link between data. These attributes that have a connection role in another table are called foreign keys.
The properties that a relationship must satisfy
The components of each tuple (record) in the relationship must be atomic, that is, each column of the table cannot be subdivided.
The value of each column in the table can only be taken from the same field, and two identical rows are not allowed.
The order of rows and columns in the table can be exchanged arbitrarily
Entity integrity constraint rules: means that the primary key in the relationship does not allow null values
Referential integrity constraint rules: also called referential integrity rules, which means that records that do not exist cannot be referenced.
User-defined integrity constraint rules: refers to constraints on the data type, length, value range, etc. of each data in the relational schema, which are uniformly controlled by the user through the data language provided by the relational DBMS.
Three elements of relational algebra operations: [operand, result] (relationship), operator
Traditional set operations include union, intersection, and difference, which are used to implement data operations such as insertion, deletion, and modification.
Specialized relational operations include projection, selection, and connection, used to implement data queries
SQL consists of four parts: data definition, data manipulation, data control, and regulations for using embedded SQL.
Main features of SQL language
SQL language is similar to the natural language of English, simple and easy to use
SQL language is a non-procedural language, that is, the user only needs to ask what to do, and does not need to care about how to do it, nor does he need to know the access path of the data, he only needs to specify the required data.
SQL language is a set-oriented language. The operation object of each command is one or more relationships, and the result is also a relationship.
The SQL language is both a self-contained language and an embedded language. Can be used independently or embedded into the host language
SQL language integrates data query, data definition, data manipulation, data control and other functions
The content of database design includes two aspects: structural feature design and behavioral feature design.
Basic principles of database design: simplicity, non-redundancy
Database design steps are generally divided into seven stages: planning, requirements analysis, conceptual design, logical design, physical design, implementation, operation and maintenance stages
basic knowledge
Access is a powerful and easy-to-use desktop relational database management system
The application builders provided by Access2010 include: table builder, query builder, macro builder, report designer
In the design view of the table, each field has a design category. Access allows nine data types, text, note, number, date/time, currency, yes/no, CLE object, hyperlink, and attachment.
You can use the LIKE operator to find field values that match the specified pattern. For the pattern, you can specify a complete value, or you can use wildcards to find values within a certain range.
The process of using database technology to manage data
design database
build database
Create tables, indexes, and views in the database
Perform various operations on data in the database, including insertion, modification, deletion, query, statistics, analysis, etc.
database maintenance
Steps to establish a relationship between tables: Open the database - start the relationship tool - add a relationship table - view the relationship diagram - create a table relationship
Access database management system
Index is a technology that arranges the records in the data table in an orderly manner based on the order of a certain keyword or keyword expression value in the data table.
A view is a special type of data table, which often consists of some text fields or records in one or more tables (or views).
The purpose of creating a view
Ensure data integrity and completeness
Easy to use
Simplify database operation and management
Structured Query LanguageSQL
SQL is a standard relational database language that integrates data definition, data manipulation, data query, and data control functions. Its core function is query
Characteristics of SQL language
non-procedural language
Powerful functions and simple operation
There are only nine core functions: SELECT, CREATE, DROP modification, ALTEP modification, INSERT insertion, DELETE deletion, UPDATE update, and two less commonly used commands (GRANT, REVOKE)
SQL clause
Use Access forms to implement data processing
The form is the interface between the user and the Access database. It is an operation interface for users to use Access to process their own data.
The elements that make up a form are called controls
Forms are divided into: column form; tabular form; data presentation form; subform; multi-page form; pivot table
There are three ways to create a form: automatically create a form, use the form wizard, and use design view.
Controls are objects on a form or report that are used to display data, perform operations, or decorate the form or report.
Report processing
A report is an object in the Access database, which prints out formatted data information according to specified rules.
The data source of the report can be a data table or query. The report can group, calculate and summarize the data.
Functions of reports: output data in formatted form; summarize data in groups; display chart data; can output various styles of reports; can perform statistical calculations on data; can sneak into images or pictures to enrich data display
Access's report operation provides four views: report view, print preview view, layout view, and design view.
Type of report: Column format; Table format; Pivot chart, Pivot table report; Label report;
Report creation process: select the record source, select the report tool, and create the report
Access programming
In Access, programming is the process of adding functionality to a database using Access macros or Visual Basic for Applications (VBA) code
Deciding whether to use macros, VBA, or both depends largely on how you plan to deploy or distribute your database
Macros are tools that allow you to automate tasks and add functionality to forms, reports, and controls