Basic Concepts of
Database 1. The role of database
① Store a large amount of data for easy retrieval and access
② Keep data information consistent and complete
③ Sharing and security
④ Generate new useful information through combined analysis
2. Database and application ① Function of
application
: Respond to operations and display results, request data from the database
Requirements: Beautiful, easy to operate
②Database:
Function: Store data, check data, and generate new data
Requirements: Unity, security, performance, etc.
3. The popular database in the enterprise
①Oracle (also known as: large database)
Oracle's
products Free products, service charges
* generally used by large companies' fund tables
②SQL Server
Microsoft products
Multiple versions for different user groups
Enterprise Edition
Standard Edition
work Group Edition
Development Edition
Evaluation Edition
Easy to use ③DB2
IBM
products
Support multiple operating systems, various types of hardware and devices The operating
system can realize cross-platform Products owned by Oracle. Open source code website is widely used
4. Entities in the database are
things that exist objectively and can be described,
and "entities" use tables in the database instead of
"tables":
rows: records
Columns: fields
The database is the "warehouse" of "data" The
database contains tables , relationship and operation object
The data is stored in the table
5. Database management (operation)
①Retrieve data
②Insert data
③Update data
④Delete data
Referred to as "add, delete, modify and check"
Database System (DBS): Warehouse
Database Management System (DBMS): Multiple users can implement at the same time (add, delete, modify and check)
6. The basic configuration required for database installation:
① Processor: at
least 600-MHz Pentium processor.
Recommended: 1GHZ or higher
② Memory:
Minimum: 512MB
Recommended: 1GB or more
③ Disk capacity:
360MB (typical installation)
750MB (full installation)
④ Operating system
Different versions of installation support different operating systems
7. Database files and transaction log files
(1) Data file
①.mdf (main data file): mainly responsible for the management and monitoring of data files (core operations), and only one
②.ndf (secondary data file): available There may be none, there may be more than one. When the data workload of the main data file is too large, auxiliary
(2) log file:
①.ldf: record the running status of the entire data file, including error information and records. It is helpful for us to view the running performance of the database
* log file: generally use one, you can also use multiple
SQl Server database 1. SQL
Server service startup method
(1) Start in the service of the operating system
① Click My Computer → Right-click → Management → Services and Applications → Services → Find the corresponding version of SQL Server in the service → Start the service → It is enough to display running in the status column
② Windows key + R → enter services.msc → service → find the corresponding version of SQL Server in the service → start the service → display running in the status column
(2) SQL Server Start in Management Studio
2. Link to the server
Server name: generally "." or "." + server name
Authentication: There are two kinds → ① SQL Server authentication (user name and password required) ② Windows authentication (user name and password are not required)
3. System database and user database
(1) System database
①master (database core): responsible for the entire running process of the database and monitoring the running status of the database
②model (model database): providing user reference structure
③tempdb (temporary database): when we perform " The temporary data generated when adding, deleting, modifying and checking” is saved to the temporary database
④msdb (warning database): stores some error information
⑤Resource (database resource):
(2) User database
is a database created and used by yourself
4. Create a login name
* Create a new login name and disable or delete the "sa" account to ensure the security of the database
* "sa" is the administrator's default login name
(1) Disable:
Security → Login name → Find the login name → Right-click → Properties → Status → Login settings are changed to Disabled
(2) Delete:
Security → Login Name → Find the Login Name → Delete
(3) New Login Name:
*If you use the administrator to disable all login names, go out bug
① Use Windows identity Login→Security→Select Login Name→Right Click→New Login Name Fill in the Login Name
→Select Authentication Type→Enter Password→Cancel Enforce Password Policy Change password ② Modify administrator privileges (modify to the highest): server role → select sysadmin ③ View status If the login changes, modify it to the startup status
5. Creation and management of database
(1) Create:
database → select, right click → enter database name
Create secondary data file: add → suffix name .datal
owner: associate
the login name with low access authority to associate the login with high access authority Logins with low access privileges will have higher privileges