Bài giảng Hệ cơ sở dữ liệu - Chương 1: Giới thiệu về cơ sở dữ liệu

Trong lĩnh vực Công Nghệ Thông Tin nói riêng, yêu cầu quan trọng nhất của người học đó chính là thực hành. Có thực hành thì người học mới có thể tự mình lĩnh hội và hiểu biết sâu sắc với lý thuyết. Với ngành mạng máy tính, nhu cầu thực hành được đặt lên hàng đầu. Tuy nhiên, trong điều kiện còn thiếu thốn về trang bị như hiện nay, người học đặc biệt là sinh viên ít có điều kiện thực hành. Đặc biệt là với các thiết bị đắt tiền như Router, Switch chuyên dụng

Giảng viên: Trần Thị Kim Chi

Introduction SQL Server

3

2 What is Database Management System

Introduction about SQL Server 2008

• Data is raw, unorganized facts that need to be processed.

Data are any facts, numbers, or text that can be processed

by a computer

• Information

– When data is processed, organized, structured orpresented in a given context so as to make it useful, it iscalled information

Data and Information

1

Data (dữ liệu) và information (thông tin)

DỮ LIỆU (DATA)

THÔNG TIN (INFORMATION)

XỬ LÝ

Data (dữ liệu) và information (thông tin)

Thông tin: dữ liệu trong ngữ cảnh

STT Mã sinh viên Họ và tên sinh viên Lớp Tuổi

…

Dữ liệu

…

 A data model is a “description” of both a container for dataand a methodology for storing and retrieving data fromcontainer

 Data model is

 Not a thing

 You cannot touch it

 Data model are abstractions, mathematical algorithms & Concepts.

Data Model

1

• A database a set of data that has a regular structure andthat is organized in such a way that a computer can easilyfind the desired information.

Database

Application Program 2 Application Program 1

Application Programs

Database management systems follow particular models (known as database models) to store and manipulate

data

A database model is characterized by:

2 The way data in the

• Persistent:

– Should be able to store all kinds of data that exists in this real world.

• Interrelated:

– Data and application should be isolated.

– Should be able to relate the entities / tables in the database by means of a relation i.e.; any two tables should be related.

• Shared:

– Multiple users should be able to access the same database, without affecting the other user.

– Database should also provide security,

– Database should also support ACID property i.e.; while performing any transactions like insert, update and delete, database makes sure that the real purpose of the data is not lost.

 Objective

 Ensuring data completeness

 Avoiding data redundancies

 Facilitating data access

 Requirement analysis

What does the user want?

 Conceptual database design

Defining the entities and attributes, and the

relationships between these The ER model

 Physical database design

Implementation of the conceptual design using a

Database Management System

Steps in Database Design

ER model & Relational Data Model

Bundoora Norman

8507

Balwyn Mary

8452

Bundoora Glen

3936

Kew Robert

1108

Suburb Name

Id

Student

Takes

29 8507

23 8507

23 1108

21 1108

SNO SID

CSCE VB

29

Maths Algebra

18

CSCE Database

23

CSCE Systems

21

Dept Name

No

Subject

Bundoora Norman

8507

Balwyn Mary

8452

Bundoora Glen

3936

Kew Robert

1108

Suburb Name

Id

Student

Takes

29 8507

23 8507

23 1108

21 1108

SNO SID

CSCE VB

29

Maths Algebra

18

CSCE Database

23

CSCE Systems

21

Dept Name

No

Subject

Relational Database

Entities:

Student (Id, Name, Suburb)

Subject (No, Name, Dept)

Relationships:

Student

Subject

Takes

ER models view the world by entities and relationships

Relational models view the world by relations

• “A DBMS that manages data

as collection of tables in which

all data relationships are

represented by common values

in related tables.”

•“A DBMS that follows all the

twelve rules of CODD is called

• Table: information about a

single entity

• Primary key: (set of)

column(s) that uniquely

identifies a record

• Foreign key: (set of)

column(s) used to link table

TABLE Structure

Attributes

Cardinality

Primary Key

Tuples

Supplier

DomainDomain

The Relational Database

• Chitiethoadon: Mô tả các thông tin chi tiết của từng hóađơn như Mahd, Masp, Soluong, DongiaBan.

Example: TABLE Structure

Example: TABLE Structure

Bài tập

Việc quản lý nhân viên của một công ty như sau:

• Công ty gồm nhiều nhân viên, mỗi nhân viên có một MANV duy nhất, mỗi MANV xác định Hoten, Phai, NgaySinh, Phongban Mỗi nhân viên chỉ do một phòng ban quản lý.

• Mỗi phòng ban có một MAPB duy nhất, mỗi MAPB xác dịnh TenPB, DiaDiem, MaTP (Mã người phụ trách), KPHD(Kinh phí hoạt động), DT (Doanh thu của từng phòng ban).

• Nhân viên được chia làm hai loại nhân viên Nhân viên hành chánh và nhân viên tham gia sản xuất Nhân viên hành chánh làm việc theo giờ hành chánh Nhân viên tham gia sản xuất thì làm nhiều công việc khác nhau.

• Mỗi công việc có một mã MACV, Macv xác định TENCV, DONGIA Công ty có tối đa

Exercise

Bài tập

Câu hỏi:

• Xây dựng mô hình thực thể kết hợp gồm: Xác định các thực thể, thuộc tính, khóa, các mối kế hợp và vẽ

mô hình thực thể kết hợp

• Chuyển mô hình thực thể về lược đồ cơ sở dữ liệu quan hệ và xác định các khóa

• Xác định các mối quan hệ và các ràng buộc của lược

đồ cơ sở dữ liệu trên

Advantages

• Reduced data redundancy

• Reduced updating errors and increased consistency

• Greater data integrity and independence from

applications programs

• Improved data access to users through use of host and query languages

• Improved data security

• Reduced data entry, storage, and retrieval costs

• Facilitated development of new applications program

• Database systems are complex, difficult, and consuming to design

time-• Substantial hardware and software start-up costs

• Damage to database affects virtually all applicationsprograms

• Extensive conversion costs in moving form a file-basedsystem to a database system

• Initial training required for all programmers and users

• DataBase Management System (DBMS)

– A database management system (DBMS) is systemsoftware for creating and managing databases TheDBMS provides users and programmers with asystematic way to create, retrieve, update andmanage data

DBMS – DataBase Management System

DBMS – DataBase Management System

Components of Database System

• Users : Users may be of various type

such as DB administrator, System

developer and End users.

• Database application : Database

Departmental, Enterprise and Internal

• DBMS : Software that allow users to

define, create and manages database

access, Ex: MySql, Oracle etc.

• Database : Collection of logical data.

CHARACTERISTICS OF THE DATABASE MANAGEMENT

SYSTEM

• Data Independence: The DBMS provides an abstract view of the

data that hides such details

• Efficient Data Access: A DBMS utilizes a variety of sophisticated

techniques to store and retrieve data efficiently

• Data Integrity and Security: If data is always accessed through

the DBMS, the DBMS can enforce integrity constraints

DBMS – DataBase Management System

CHARACTERISTICS OF THE DATABASE MANAGEMENT

SYSTEM

• Data Administration: When several users share the data,

Experienced professionals who understand the nature of the data being managed, and how different groups of users use it, can be responsible for organizing the data representation to minimize redundancy and for fine tuning the storage of the data to make retrieval efficient

• Concurrent Access and Crash Recovery: A DBMS schedules

concurrent accesses to the data in such a manner that users can think of the data as being accessed by only one user at a time

Further, the DBMS protects users from the effects of system

failures

DBMS – DataBase Management System

Functions of DBMS

• Provides data Independence

• Concurrency Control

• Provides Recovery services

• Provides Utility services

• Provides a clear and logical view of the process that

manipulates data

DBMS – DataBase Management System

Quan hệ

Quan hệ

• Database (Data) Tier: the database resides

along with its query processing languages We

also have the relations that define the data and

their constraints at this level.

• Application (Middle) Tier: reside the

application server and the programs that

access the database For a user, this

application tier presents an abstracted view of

the database The application layer sits in the

middle and acts as a mediator between the

end-user and the database.

• User (Presentation) Tier − End-users operate

on this tier and they know nothing about any

existence of the database beyond this layer At

this layer, multiple views of the database can be

provided by the application All views are

generated by applications that reside in the

application tier.

SERVICES OF DBMS

• Data Storage Management

• Data Manipulation Management

• Data Definition Services

• Data Dictionary/System Catalog Management

• Database Communication Interfaces

• Authorization / Security Management

• Backup and Recovery Management

• Concurrency Control Service

• Transaction Management

• Database Access and Application Programming Interfaces

DBMS – DataBase Management System

Advantages of a DBMS

• Segregation of applicaion program

• Minimal data duplicacy

• Easy retrieval of data

• Reduced development time and maintainance need

DBMS – DataBase Management System

• RDBMS stands

for Relational Database Management System RDBMS is the

basis for SQL, and for all modern database systems like MS SQL Server, IBM DB2, Oracle, MySQL, and Microsoft

Access

• A Relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E F Codd

Table 1 Key Data

Table 2 Key

Quan hệ

Database

Relational Database Management System

Hardware and Software

requirements are minimum requirements are HighHardware and Software

Platform used is normally DOS Platform used can be any DOS,

UNIX,VAX,VMS, etc Uses concept of a file Uses concept of table

DBMS normally use 3GL RDBMS normally use a 4GL

Examples are dBase, FOXBASE, etc Examples are ORACLE, INGRESS,

SQL Server, Access, etc

• SQL stands for Structured Query Language

• Microsoft SQL Server is a relational database

management system developed by Microsoft

• The primary query languages: T-SQL and ANSI SQL

• SQL Server includes several components

• Primary function: store and retrieve data as requested

by other software applications on the same computer or

on another computer across a network

Storage Engine

Server

Local Database

Database API (OLE DB, ODBC, DB-Library)

Client/Server Architecture

Relational Database Management System

SQL Server Client

Results

Client Application

OLAP OLTP

Query

Ms SQL Server Components

• SQL Server Integration Services (SSIS) is a platform

for building high performance data integration solutions,including extraction, transformation, and load packagesfor data warehousing

Ms SQL Server Components

• SQL Server Database Engine is the core service for

storing, processing, and securing data

– This includes creating tables for storing data, anddatabase objects such as indexes, views, and storedprocedures for viewing, managing, and securing data

Ms SQL Server Components

• SQL Server Reporting Services (SSRS) includes:

– A complete set of tools that you can use to create andmanage reports,

– An application programming interface (API) thatallows developers to integrate or extend data andreport processing in custom applications

Ms SQL Server Components

SQL Server Analysis Services :

• Analysis Services delivers Online Analytical Processing

and Data Mining functionality for Business Intelligence applications

Ms SQL Server Components

SQL Server Service Broker :

• Service Broker, internal or external processes can send and receive guaranteed, asynchronous messages by using extensions to Transact- SQL Data Manipulation Language (DML)

• Messages can be sent to a queue in the same database as the sender,

to another database in the same SQL Server instance, or to another SQL Server instance either on the same server or on a remote server.

Ms SQL Server Components

• SQL Server Replication is a set of technologies for

copying and distributing data and database objects fromone database to another, and then synchronizingbetween databases to maintain consistency

Ms SQL Server Components

• Full – Text Search lets users and applications run full-text

queries against character-based data in SQL Server tables

• The full-text index includes one or more character-basedcolumns in the table

Ms SQL Server Components

• Notification Services is a platform for developing and

deploying applications that generate and send notifications tosubscribers The notifications generated are personalized,timely messages that can be sent to a wide range of devices,and that reflect the preferences of the subscriber

Ms SQL Server Components

• SQL Server Management Studio

• SQL Server Configuration Manager

• SQL Server Agent

• SQL Profiler

Ms SQL Server Tools

• SQL Server Management Studio (SSMS) is used for

configuring, managing, and administering allcomponents within Microsoft SQL Server

– This includes both script editors and graphical toolswhich work with objects and features of the server

SQL Server Management Studio

• SQL Server Configuration Manager is a tool provided

with SQL Server 2008 for managing the servicesassociated with SQL Server and for configuring thenetwork protocols used by SQL Server

• Primarily, SQL Server Configuration Manager is used tostart, pause, resume, and stop SQL Server services and

to view or change service properties

SQL Server Configuration Manager

• SQL Server Agent is a scheduling tool integrated into

SSMS that allows convenient definition and execution of scheduled scripts and maintenance jobs

SQL Server Agent

• The SQL Server Profiler is a GUI interface to the SQL

Trace feature of SQL Server that captures the queriesand results flowing to and from the database engine

SQL Profiler

Transa

• Implementation of Entry-Level ANSI ISO Standard

• Composing of 3 categories

– Data Definition Language Statements (DDL)

– Data Control Language Statements (DCL)

– Data Manipulation Language Statements (DML)

SQL Command

SQL Command

CREATE Creates a new table, a view of a table, or other

object in databaseALTER Modifies an existing database object, such as

a table

DROP Deletes an entire table, a view of a table or

other object in the database

DDL - Data Definition Language

UPDATE Modifies records

DELETE Deletes records

SQL Command

DCL - Data Control Language

Command Description

GRANT Gives a privilege to user

REVOKE Takes back privileges granted from user

Evolution of SQL Server

SQL Server 7.0

SQL Server 2005

SQL Server 2000

Realibility & Security Integrated Business Intelligence

Performance and Scalability

Automatic Tuning

• Reliability and scalability advancements

• Deep XML support

• Data warehousing

• SQL Server CE

• 64 bit support

• Re-architecture

of relational server

• First to include OLAP in

• Programmability advancements

• End-to-end business intelligence

• Manageability

• Support for multiple types of data

SQL Server 2008

• Secure trusted platform for data

• Productive policy-based management

• Optimized and predictable system performance

• Dynamic development

• Beyond relational data

• Pervasive Business Insight

SQL Server Editions

SQL Server 2008 Standard Edition

• This is the version intended for the masses to medium-sized systems who don’t require the performance, scalability, and availability provided by Enterprise Edition.

SQL Server 2008 Enterprise Edition

• Provides the most scalability and availability of all editions and

is intended for systems that require high performance and availability, such as large-volume websites, data warehouses, and high-throughput online transaction processing (OLTP) systems.

Other SQL Server 2008 Editions

• The Standard and Enterprise Editions of SQL Server 2008 are

SQL SERVER 2008 R2 EDITIONS.