1. CS4540 Special Topics in Web Development SQL and MS SQL
Chengyu Sun
California State University, Los Angeles

2. A Relational DB Example
Employees
EmployeeId
FirstName
LastName
DateHired
SupervisorId 1
John
Doe
null 2
Jane
Projects
ProjectMembers
ProjectId
Name
LeaderId 1
Firestone 2
Blue
ProjectId
EmployeeId 1 2

3. Terminology DBMS DB DB DB Database Schema Schema Schema
Tables (relations)
Views, indexes
Procedures and triggers …
Schema
Schema
Schema
Database

4. DBMS
Database Management System (DBMS) is a software that manages databases
Common DBMS
Commercial – Oracle, IBM DB2, MS SQL Server, Access
Open source – MySQL, PostgreSQL

5. Database and Schema
A database is a collection of data managed by a DBMS
Many DBMS also support sub-collections within a database called schemas
The default schema in MS SQL Server is dbo (stands for database owner)
Tables, indexes, stored procedures … are often called database objects or schema elements

6. More Terminology Table (relation) Attributes (fields, columns)
StudentId
Name
1001
John Doe
1002
Jane Doe
Rows
(Records)
(Tuples)
Students
Table schema: Students( StudentId, Name )
Database schema: database name + table schemas

7. Client-Server Architecture
SSMS
Azure Data Studio
sqlcmd
Applications …
SQL Server DB DB DB

8. Connect to a Database Use one of the client software
Connection information
Host
Port (default 1433)
Username
Password
Database/Schema
See Using MS SQL Server on ECST-CSPROJ2

9. SQL Structured Query Language
Standard query language of relational databases
Supported by all major relational databases with some variations
Transact-SQL (T-SQL) for MS SQL Server

10. Create Tables
Coding conventions
Data types and literals
SQL script

11. Coding Conventions
Plural form for table names, and singular form for column names
PascalCasing for names, and capitalize SQL keywords
Use [] around names in case they contains special characters

12. Common Data Types Numeric String Date and time
bit, int, smallint, bigint
real, float(n)
String
char(n), varchar(n)
nchar(n), nvarchar(n) for Unicode
Date and time
date, time, datetime, datetime2

13. About IDENTITY Similar to AUTO_INCREMENT in MySQL
Can be customized with seed and increment, e.g. IDENITY(1000,1)
Must set IDENTITY_INSERT to ON before inserting an explicit value to an identity column

14. SQL Literals Called Constants in MS documentation
Unicode strings are prefixed with N
Default date format is 'YYYY-MM-dd'

15. SQL Script A text file contains SQL statements and comments
Usually uses .sql suffix
Use sqlcmd -i <script> to run script on command line
When using sqlcmd, the GO command sends the preceding statements to SQL server to execute as a batch

16. Simple Selections
Example: find the employees whose last names are Doe

17. Using Functions T-SQL Functions
Example: find the names of the employees who were hired in 2015

18. Join Example: find the name of the leader of the project Blue
Equi-join
Inner join

19. Aggregation
Example: list the name and the number of employees for each project

20. Other Statements Change password ALTER LOGIN <username> WITH
PASSWORD = '<new_password>'
OLD_PASSWORD = '<old_password>'

21. References
Transact-SQL (T-SQL) Reference