The document discusses key concepts related to SQL Server databases including: - SQL Server operates separately from client applications and requires a connection to transmit requests and responses. - Management Studio is used to start/stop the SQL Server service and write/execute T-SQL statements. - Databases contain tables, stored procedures, views, and indexes which are used to organize and retrieve data. - Security is provided through login accounts and user roles within databases.

1. CIS282

2. Database Server
 Operates as a separate “process”
 Need to communicate with the server using a separate
application
 Connection required to transmit request and response
 Management Studio and SQL Server are different
programs

3. Managing SQL Server
 Management Studio gives access to most
functions/operations
 Query window provides method to write/execute T-
SQL statements
 “T” = transact
 SQL Service Manager provides way to start/stop Server

4. SQL Server Databases
 Two files are maintained
 Data file (.mdf)
 Transaction Log file (.ldf)
 Files can be spread over multiple machines
 Always need a primary file group

5. Database Contents
 Tables
 User tables hold data
 System tables hold data about the database
 Stored Procedures, User Defined Functions
 Views
 Indexes

6. Default Databases
 Master: Logins/User roles; system configuration;
names/locations of databases; SQL Server startup
 Tempdb: Lasts duration of SQL Server session;
temporary holding space
 Model: Sets characteristics of new databases
 MSDB: Holds information about jobs SQL Server
Agent runs

7. Security
 Windows Authentication: Windows network logins
used
 Mixed-mode: Windows OR SQL Server logins used
 Login: To access server
 User: To access a database
 Network security trumps all….

8. Roles
 Server – administrative functions
 Task based:
 Backup
 Create database
 Roles are fixed
 Database/Application – groups of users with common
activities
 Read/write all data
 Read/write select data
 Read data only

9. Normalization
 Process for reducing duplicate and redundant data
 1st Normal Form: eliminate repeating groups
 2nd Normal Form: each column in a table depends on
the primary key
 can’t get information with only part of the key
 3rd Normal Form: A column cannot be dependent on
another column that isn’t the primary key

10. Relationships
 Types
 One-to-one
 One-to-many
 Many-to-many
 Requires a primary key on the ‘one’ side, foreign key on
the ‘many’ side
 Referential Integrity defines how values work across
tables

11. Table Definition
 Fields need a name and datatype
 SQL Server datatypes are different from Access and
procedural programming language datatypes
 Fieldnames can include spaces – but poor practice
 Identity – create unique number for each row

12. Constraints
 Allow Null – value not required to add record
 Check Constraints – test field or row values
 Default value – if no data is entered into a field
 Unique – values must be different for each row

13. Database Diagrams
 Illustrate database design
 Add, modify tables, indexes, relationships
 Can control view, table details

14. Indexes
 Help to select and find records
 Serve as a “cross-reference”
 Can be based on one or more fields

15. Good Index Characteristics
 Low maintenance columns
 Includes columns used frequently in Where or Order
By clauses
 Don’t have to go out to table for data
 Help search for ranges of records

16. Action Queries
 Insert: insert into tablename(fieldlist) values(valuelist)
 Update: update tablename set
field1=value1, field2=value2
 Delete: delete from tablename [where condition]

17. Select Statement
 Can use an alias for fields and/or tables
 Select fields
 From table
 Join table On field=field
 Inner – both tables have records with
matching values
 Outer – all records from one table and any
matches found in second table

18. Where
 Conditions to determine records returned
 Multiple conditions require And … Or
 Can use where clause to implement join between
tables
 Sub-queries allow tables to be limited by values in a
second table without using a join

19. Views
 Pre-defined select statement
 Used like a virtual table
SELECT * FROM v_CurrentEmployees

20. View Performance
 By default views run just as a query processed from
command line
 Adds second step to execution:
 select from view
 execute view itself
 Can add an index to speed execution
 Specific requirements when creating an index on a view