1. COS 346 Day 3 DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

2. Agenda Questions? Assignment 1 is posted in BlackBoard
Due TODAY (like RIGHT NOW!)
Finish Intro to SQL
Begin discussions on the relational model and normalization
Make sure you read ahead
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

3. Database Processing: David M. Kroenke’s Chapter Two:
Fundamentals, Design, and Implementation
Chapter Two:
Introduction to
Structured Query Language
Part Two
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

4. Using MS Access - Results
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

5. Using Access 2007 DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

6. Using MS SQL Server [SQL Query Analyzer]
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

7. Using Oracle [SQL*Plus]
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

8. Using Oracle [Quest Software’s TOAD]
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

9. Using MySQL [MySQL Command Line Client]
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

10. Using MySQL [MySQL Query Browser]
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

11. Connecting SQL server 2005
Start Microsoft SQL server management Studio
Select Littleblack\”lastname” If you are connecting from outside the UMFK network use littleblack.umfk.maine.edu\”lastname”
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

12. SQL 2005 DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

13. Executing SQL DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

14. Sorting the Results: ORDER BY
SELECT *
FROM Chapter_2.ORDER_ITEM
ORDER BY OrderNumber, Price;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

15. Sort Order: Ascending and Descending
SELECT *
FROM Chapter_2.ORDER_ITEM
ORDER BY Price DESC, OrderNumber ASC;
NOTE: The default sort order is ASC – does not have to be specified.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

16. WHERE Clause Options: AND
SELECT *
FROM Chapter_2.SKU_DATA
WHERE Department = 'Water Sports'
AND Buyer = 'Nancy Meyers';
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

17. WHERE Clause Options: OR
SELECT *
FROM Chapter_2.SKU_DATA
WHERE Department = 'Camping'
OR Department = 'Climbing';
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

18. WHERE Clause Options:- IN
SELECT *
FROM Chapter_2.SKU_DATA
WHERE Buyer IN ('Nancy Meyers',
'Cindy Lo', 'Jerry Martin');
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

19. WHERE Clause Options: NOT IN
SELECT *
FROM Chapter_2.SKU_DATA
WHERE Buyer NOT IN ('Nancy Meyers',
'Cindy Lo', 'Jerry Martin');
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

20. WHERE Clause Options: Ranges with BETWEEN
SELECT *
FROM Chapter_2.ORDER_ITEM
WHERE ExtendedPrice
BETWEEN 100 AND 200;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

21. WHERE Clause Options: Ranges with Math Symbols
SELECT *
FROM Chapter_2.ORDER_ITEM
WHERE ExtendedPrice >= 100
AND ExtendedPrice <= 200;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

22. WHERE Clause Options: LIKE and Wildcards
The SQL keyword LIKE can be combined with wildcard symbols:
SQL 92 Standard (SQL Server, Oracle, etc.):
_ = Exactly one character
% = Any set of one or more characters
MS Access (based on MS DOS)
? = Exactly one character
* = Any set of one or more characters
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

23. WHERE Clause Options: LIKE and Wildcards (Continued)
SELECT *
FROM Chapter_2.SKU_DATA
WHERE Buyer LIKE 'Pete%';
MS ACCESS Buyer LIKE ‘Pete*’;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

24. WHERE Clause Options: LIKE and Wildcards (Continued)
SELECT *
FROM Chapter_2.SKU_DATA
WHERE SKU_Description LIKE '%Tent%';
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

25. WHERE Clause Options: LIKE and Wildcards
SELECT *
FROM Chapter_2.SKU_DATA
WHERE SKU LIKE '%2_ _';
MS ACCESS SKU LIKE ‘*2??’;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

26. SQL Built-in Functions
There are five SQL Built-in Functions:
COUNT
SUM
AVG
MIN
MAX
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

27. SQL Built-in Functions (Continued)
SELECT SUM (ExtendedPrice)
AS Order3000Sum
FROM ORDER_ITEM
WHERE OrderNumber = 3000;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

28. SQL Built-in Functions (Continued)
SELECT SUM (ExtendedPrice) AS OrderItemSum,
AVG (ExtendedPrice) AS OrderItemAvg,
MIN (ExtendedPrice) AS OrderItemMin,
MAX (ExtendedPrice) AS OrderItemMax
FROM Chapter_2.ORDER_ITEM;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

29. SQL Built-in Functions (Continued)
SELECT COUNT(*) AS NumRows
FROM ORDER_ITEM;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

30. SQL Built-in Functions (Continued)
SELECT COUNT
(DISTINCT Department)
AS DeptCount
FROM Chapter_2.SKU_DATA;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

31. Arithmetic in SELECT Statements
SELECT Quantity * Price AS EP,
ExtendedPrice
FROM Chapter_2.ORDER_ITEM;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

32. String Functions in SELECT Statements
SELECT DISTINCT RTRIM (Buyer)
+ ' in ' + RTRIM (Department) AS Sponsor
FROM Chapter_2.SKU_DATA;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

33. The SQL keyword GROUP BY
SELECT Department, Buyer,
COUNT(*) AS
Dept_Buyer_SKU_Count
FROM Chapter_2.SKU_DATA
GROUP BY Department, Buyer;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

34. The SQL keyword GROUP BY (Continued)
In general, place WHERE before GROUP BY. Some DBMS products do not require that placement, but to be safe, always put WHERE before GROUP BY.
The HAVING operator restricts the groups that are presented in the result.
There is an ambiguity in statements that include both WHERE and HAVING clauses. The results can vary, so to eliminate this ambiguity SQL always applies WHERE before HAVING.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

35. The SQL keyword GROUP BY (Continued)
SELECT Department, COUNT(*) AS
Dept_SKU_Count
FROM SKU_DATA
WHERE SKU <>
GROUP BY Department
ORDER BY Dept_SKU_Count;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

36. The SQL keyword GROUP BY (Continued)
SELECT Department, COUNT(*) AS
Dept_SKU_Count
FROM Chapter_2.SKU_DATA
WHERE SKU <>
GROUP BY Department
HAVING COUNT (*) > 1
ORDER BY Dept_SKU_Count;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

37. Querying Multiple Tables: Subqueries
SELECT SUM (ExtendedPrice) AS Revenue
FROM ORDER_ITEM
WHERE SKU IN
(SELECT SKU
FROM SKU_DATA
WHERE Department = 'Water Sports');
Note: The second SELECT statement is a subquery.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

38. Querying Multiple Tables: Subqueries (Continued)
SELECT Buyer
FROM SKU_DATA
WHERE SKU IN
(SELECT SKU
FROM ORDER_ITEM
WHERE OrderNumber IN
(SELECT OrderNumber
FROM RETAIL_ORDER
WHERE OrderMonth = 'January'
AND OrderYear = 2004));
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

39. Querying Multiple Tables: Joins
SELECT Buyer, ExtendedPrice
FROM SKU_DATA, ORDER_ITEM
WHERE SKU_DATA.SKU = ORDER_ITEM.SKU;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

40. Querying Multiple Tables: Joins (Continued)
SELECT Buyer, SUM(ExtendedPrice)
AS BuyerRevenue
FROM SKU_DATA, ORDER_ITEM
WHERE SKU_DATA.SKU = ORDER_ITEM.SKU
GROUP BY Buyer
ORDER BY BuyerRevenue DESC;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

41. Querying Multiple Tables: Joins (Continued)
SELECT Buyer, ExtendedPrice, OrderMonth
FROM SKU_DATA, ORDER_ITEM, RETAIL_ORDER
WHERE SKU_DATA.SKU = ORDER_ITEM.SKU
AND ORDER_ITEM.OrderNumber =
RETAIL_ORDER.OrderNumber;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

42. Subqueries versus Joins
Subqueries and joins both process multiple tables.
A subquery can only be used to retrieve data from the top table.
A join can be used to obtain data from any number of tables, including the “top table” of the subquery.
In Chapter 7, we will study the correlated subquery. That kind of subquery can do work that is not possible with joins.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

43. David M. Kroenke’s Database Processing Fundamentals, Design, and Implementation (10th Edition)
End of Presentation:
Chapter Two Part Two
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

44. SQL for SQL Server Bijoy Bordoloi and Douglas Bock
Chapter 1: Introduction

45. SQL
SQL, pronounced ‘Sequel’ or simply S-Q-L, is a computer programming language that was developed especially for querying relational databases using a nonprocedural approach.
The term nonprocedural means that you can extract information by simply telling the system what information is needed without telling it how to perform the data retrieval.
Transact-SQL or T-SQL is Microsoft's implementation of the SQL language.

46. Chapter OBJECTIVES
Develop a basic understanding of the relational database.
Learn the general capabilities of a relational database management system.
Become familiar with the features of the SQL Server relational database management system.
Learn to use the SQL Query Analyzer and SQL Server Management Studio .
Become familiar with the basic relational operations including the selection, projection, and join operations.
Become familiar with the basic syntax of the SELECT statement.
Learn the T-SQL naming conventions.

47. DATA AND INFORMATION
Information is derived from raw facts known as data.
Data has little meaning or usefulness to managers unless it is organized in some logical manner.
One of the most efficient ways to organize and manage data is through the use of database management systems (DBMS).

48. DBMS
Some popular relational DBMS products are the Oracle RDBMS, IBM’s DB2, Microsoft’s SQL Server, and Microsoft’s desktop single user RDBMS named Microsoft Access.
A DBMS provides both systems development professionals and information users with an easy-to-use interface to their organization’s database.

49. Relational Database
The most common type of DBMS software in use today is termed a relational DBMS or RDBMS.
A relational database stores data in the form of tables.
A table is defined as a collection of rows and columns.
The tables are formally known as relations; this is where the relational database gets its name.

50. TABLE

51. Characteristics of a Relation (Table)
The order of rows and columns is immaterial.
All values are atomic (indivisible) – each row/column intersection represents a single value. In other words, ‘repeating groups’ are not allowed.
Every value in a column must be a member of a conceptual set of atomic values called a domain.
Unsigned Integer domain 0 – (8 bits)
A value may be null, that is, not known or inapplicable.
A relation, by definition, cannot have duplicate rows. Every table must have a ‘Primary Key’ ,which guarantees that there are no duplicate rows.

52. Relating Tables: Foreign Keys
Foreign key – a (simple or composite) column that refers to the primary key of some table (including itself) in a database.
Foreign and primary keys must be defined on same data type (and from the same domain).
A relational DBMS can relate any data field in one table to any data field in another table as long as the two tables share a data field that is defined on the same ‘domain’ (the same data type).
Therefore, if a table has a foreign key then you can always link (‘join’) this table with the table where this foreign key is the primary key.
Foreign keys are also discussed further in Chapter 2.

53. Relating Tables

54. DATABASE MANAGEMENT SYSTEM
A database management system (DBMS) manages the data in a database.
A DBMS is a software package (collection of programs) that enables the users to create and maintain a database.
A DBMS also enables data to be shared.
SQL is the language used to create and retrieve data from a relational database using a RDMS, such as SQL Server.

55. DBMS

56. DATA Two types of data are stored within a database.
User data: Data that must be stored by an organization.
System data: Data the database needs to manage user data to manage itself. This is also termed metadata, or the data about data.

57. DBMS Services
Data definition for defining and storing all of the objects that comprise a database such as tables and indexes
Data maintenance
Data manipulation
Data display
Data integrity
Data security Database backup and recovery

58. SQL Server Versions Edition Description SQL Server Standard Edition
Small-and medium-sized businesses without large data center applications will find this edition best fits their budget. It supports up to four CPUs and 2GB of random access memory.
SQL Server Enterprise Edition
Aimed at large companies including multinational conglomerates that are moving into e-commerce. This version provides high availability and scalability. It can support up to 32 CPUs and 64GB of random access memory.
SQL Server Developer Edition
This is like the Enterprise Edition, but for system developers. It cannot be licensed for use in a production environment.

59. SQL Server Versions Contd.
SQL Server Desktop Edition
This Edition has the SQL Server database engine, but not all of the management tools or analysis services. Database size for this edition is limited to 2GB. It supports full application development and deployment for small business applications.
SQL Server 2000 Personal Edition
This version has much of the functionality of the Standard Edition. It can service small groups of concurrent access users. It will run on desktop Windows operating systems from Windows 98 to Windows 2000 Professional Edition.
SQL Server 2000 Windows CE Edition
This runs on the Windows CE operating system for pocket PC devices.

60. SQL Server 2005 Editions

61. SQL Server Features Feature Description Internet standard support
SQL Server uses Microsoft's new .NET technology to support data exchange across the Internet including new detailed support for the extensible-markup language, or XML.
Scalability
SQL Server can be used to build very large, multiprocessor systems.
Security mechanisms
SQL Server's sophisticated security mechanisms control access to sensitive data through an assortment of privileges, for example, the privilege to read or write specific information within a database.
Backup and recovery
SQL Server's sophisticated backup and recovery programs minimize data loss and downtime if problems arise.

62. SQL Server Features Cont.
Space management
SQL Servers automated space management capability makes it easy for a database administrator to manage disk space for storage. These capabilities also include the ability to specify subsequent allocations on how much disk space to set aside for future requirements.
Open connectivity
SQL Server's open connectivity functionality provides uninterrupted access to the database throughout the day. It also provides open connectivity to and from other vendors’ software.
Tools and applications
SQL Server provides a wide range of development tools, end-user query tools, and support for third-party software applications that are used to model business processes and data and to generate program language code automatically.

63. SQL: DDL and DML
SQL is used by SQL Server for all interaction with the database. SQL statements fall into two major categories:
Data Definition Language(DDL): Set of SQL commands that create and define objects in a database.
Data Manipulation Language(DML): Set of SQL commands that allow users to manipulate the data in a database.

64. SQL
SQL is basically a free format language. This means that there are no particular spacing rules that must be followed when typing SQL commands.
SQL is a nonprocedural language. This means that the user only has to specify the task for the DBMS to complete, but not how the task is to be completed. The RDBMS parses (converts) the SQL commands and completes the task.

65. Procedural and Nonprocedural
SELECT emp_last_name, emp_first_name
FROM employee
WHERE emp_last_name = 'BOCK';
intIndex = 1
DO WHILE intIndex <= Count_Of_Rows
If emp_last_name = 'BOCK' Then
DISPLAY emp_last_name,
emp_first_name
End If
intIndex += 1
LOOP

66. SQL Query Analyzer GUI can be used to: Create databases.
Develop, test, and debug stored procedures.
Run SQL scripts – these are miniature programs that contain either DDL or DML commands or a combination of these commands. An example would be a script to create a database, and then populate the tables in the database with data.
Optimize system performance.
Analyze query plans – these are the plans that the DBMS generates for processing a query.
Maintain and manage statistics concerning database performance.
Generate tune table indexes – the indexes are supposed to improve system performance for data retrieval.

67. SQL Query Analyzer Contd.

68. SQL Query Analyzer Contd.

69. SQL Query Analyzer Contd.

70. SQL Query Analyzer Contd.

71. SQL Server management studio

72. SQL Server management studio

74. Creating a Database
When SQL Server is initially installed, five system databases are generated. These are named: (1) master, (2) model, (3) msdb, (4) distribution, and (5) tempdb.
When you create a new database in SQL Server, the DBMS uses the model database as a template to create a new database.
The command to create a user database is :
CREATE DATABASE <database_name>
Note: You must have prior authorization from your system administrator to execute this command.

76. Personal Databases Everyone has their own database on little black
Admin access to personal database restricted to Tony and individual student

77. Creating a Database: In-Class Exercise
Invoke SQL management Studio, Log on to SQL Server, and Create a database called Company in your own database:
CREATE DATABASE Company;
Simply type the command in the Editor pane of the Query window and click the Execute Query button (or press the F5 key).
Once the Company database has been created, you will see it listed in the Object Browser. If you do not see it in the Object Browser, simply right-mouse click and select the Refresh option to refresh the screen.

78. The Company Database
Throughout this textbook you will study SQL commands against the backdrop of a sample database called the Company database, which is described in Appendix A. You may wish to familiarize yourself with Appendix A at this time.
Note that the Company database you just created does not contain any data yet. Chapter 2 explains the commands to populate a database through creation of tables and insertion of rows in much more detail.

79. Using a Database
After you have CREATED your database(s) you must use the USE command to select a database for future processing.
You can type the USE command into the Editor pane and execute it also.
USE Company;
The command(s) completed successfully.

80. Executing Scripts
Sometimes you need to execute a script that contains a series of SQL statements. The Editor pane can be used to create and save a script as shown in Figure 1.8.
Simply select the Editor pane to make it the active window, then use the toolbar Save option and specify the location, file name, and file format when the Save Query dialog box displays.
You should use the default filename extension of .sql when naming a script file.

81. Executing Scripts (Fig: 1.8)

82. Executing Scripts
You can also open scripts and execute them, even if they were created with another text editor, such as Microsoft Notepad or Word.
Figure 1.9 shows this operation.
Select the Load SQL Script toolbar button and when the Open Query File dialog box displays, locate and select the name of the file to be opened.

83. Executing Scripts (Fig: 1.9)

84. Creating, Saving, and Running a Sample Script
Practice creating, saving, and running a sample script file named Product.sql as shown in SQL Examples 1.1 and 1.2.
Type the code exactly as shown.
Do not worry if you do not understand (you are not expected to) the code at this point. Things will become clearer as we cover more materials in later chapters.

85. Project.sql /* SQL Example 1.1 */
/* Product.sql script – creates a Product table */
/* in the Company database */
USE Company;
CREATE TABLE product (
pro_id SMALLINT PRIMARY KEY,
pro_description VARCHAR(25),
pro_cost MONEY ); GO
INSERT INTO product VALUES (4, ‘Kitchen Table’, );
INSERT INTO product VALUES (6, ‘Kitchen Chair’, );
INSERT INTO product VALUES (12, ‘Brass Lamp’, 85.98);
SELECT * FROM product;
/* end of script file */

86. RELATIONAL OPERATIONS: OVERVIEW
SQL operations for creating new tables, inserting table rows, updating table rows, deleting table rows, and querying databases are the primary means of interfacing with relational databases.
The SELECT statement is used primarily to write queries that extract information from the database, which is a collection of related tables.

87. RELATIONAL OPERATIONS
The ability to select specific rows and columns from one or more tables is referred to as the fundamental relational operations, and there are three of these operations:
Selection
Projection
Join
The purpose of the next few slides is just to familiarize you with each of these operations. We will study these operations in detail in later chapters.

88. Selection Operation
A selection operation selects a subset of rows in a table (relation) that satisfy a selection condition. That subset can range from no rows to all rows in a table. The SELECT statement below selects a subset of rows through use of a WHERE clause.
SELECT emp_ssn, emp_last_name, emp_first_name
FROM employee
WHERE emp_ssn = ' ';
emp_ssn emp_last_name emp_first_name
Bock Douglas

89. Projection Operation
A projection operation selects only certain columns from the table, thus producing a subset of all available columns.
The result table can include anything from a single column to all the columns in the table.

90. EXAMPLE
This SELECT statement selects a subset of columns from the employee table by specifying the columns to be listed.
SELECT emp_ssn, emp_first_name, emp_last_name
FROM employee;
emp_ssn emp_first_name emp_last_name
Douglas Bock
Hyder Amin
Dinesh Joshi
more rows will display…

91. Join Operation
A join operation combines data from two or more tables based upon one or more common column values.
The relational join is a very powerful operation because it allows users to investigate relationships among data elements.
The following SELECT statement displays column information from both the employee and department tables.
This SELECT statement also completes both selection and projection operations.

92. Join Operation: Example

93. JOIN: Example
The tables are joined upon values stored in the department number columns named emp_dpt_number in the employee table and dpt_no in the department table.
SELECT emp_ssn, emp_first_name, emp_last_name, dpt_name
FROM employee, department
WHERE emp_dpt_number = dpt_no;
emp_ssn emp_first_name emp_last_name dpt_name
Douglas Bock Production
Hyder Amin Admin and Records
Dinesh Joshi Production
more rows will display…

94. SQL Syntax
Now that you've seen some basic SQL statements, you may have noticed that SQL requires you to follow certain syntax rules; otherwise, an error message is returned by the system and your statements fail to execute.

95. T-SQL Naming Rules
The rules for creating identifiers in T-SQL differ slightly from those in the ANSI/ISO-92 SQL standard.
Identifiers are the names given by information system developers and system users to database objects such as tables, columns, indexes, and other objects as well as the database itself.

96. T-SQL Naming Rules Contd.
There are several rules for naming database objects that must be followed:
Identifiers must be no more than 128 characters.
Identifiers can consist of letters, digits, or the symbols $, and _ (underscore).
The first character of an identifier must be either a letter (a-z, A-Z) or the or _ (underscore) symbol. After the first character, you may use digits, letters, or the symbols $, #, or _ (underscore).
Temporary objects are named by using the # symbol as the first character of the identifier. Avoid using this symbol as the leading character when naming permanent database objects.
symbol as the first character of an identifier denotes a variable name. Avoid using this symbol as the leading character when naming other database objects.
SQL keywords such as SELECT and WHERE cannot be used as an identifier.

97. SELECT Statement Syntax Overview
Each select statement must follow precise syntactical and structural rules.
For example, you cannot place the FROM clause before the SELECT clause, or place the FROM clause after the WHERE clause or the ORDER BY clause, and so on.
The basic syntax (including the order of various clauses) is as follows:

98. SELECT Statement Syntax Overview Contd.
SELECT [DISTINCT | ALL] [TOP n [PERCENT][WITH TIES]] {* | select_list}
[INTO {table_name} ]
[FROM {table_name [alias] | view_name}
[{table_name [alias] | view_name}]]...
[WHERE condition | JOIN_type table_name ON (join_condition) ]
[GROUP BY condition_list]
[HAVING condition]
[ORDER BY {column_name | column_# [ ASC | DESC ] } ...

99. SELECT Statement Syntax
you will learn the various clauses of the SELECT statement throughout your study of this text.
Welcome to the study of SQL!

100. SUMMARY
This chapter:
Introduced you to the basics of relational database, DBMS, and SQL.
Familiarized you with the features of the SQL Server DBMS including its GUI, the SQL Query Analyzer.
Familiarized you with the basic relational operations including the selection, projection, and join operations.
Familiarize with the basic syntax of the SELECT statement.