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

2. Agenda Questions? WebCt accounts should be available
Assignment 1 is DUE on Monday
There was some confusion due to WebCT not being accessible in the first class
Begin Intro to SQL
Chap 2 in DP
Chap 1 in SQL
Good news!
Looks like I’ll be getting CA to donate 12 or so copies of AllFusion Data Modeling Suite Bundles which includes ERwin to UMFK.
$150,000+ donation
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

3. Accessing the Cape Codd Database
Download an MS access version from WebCT under Database section (chapter_2.mdb)
Use the Oracle Server LittleBlack.advtech.local
Database SID: CapeCodd
You all have read access
Account: Cos346
Password: Cos346
At a command Prompt type (temp fix)
\\littleblack\oracle10g\namefile\fixnames.bat
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

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

5. USING SQL*Plus Worksheet
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

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

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

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

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

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

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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

25. SQL Built-in Functions (Continued)
SELECT SUM (ExtendedPrice)
AS Order3000Sum
FROM Chapter_2.ORDER_ITEM
WHERE OrderNumber = 3000;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

26. 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

27. SQL Built-in Functions (Continued)
SELECT COUNT(*) AS NumRows
FROM Chapter_2.ORDER_ITEM;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

28. 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

29. 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

30. String Functions in SELECT Statements (T-SQL)
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

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

32. 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

33. 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

34. The SQL keyword GROUP BY (Continued)
SELECT Department, COUNT(*) AS
Dept_SKU_Count
FROM chapter_2.SKU_DATA
WHERE SKU <>
GROUP BY Department
ORDER BY Dept_SKU_Count;
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 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

36. Querying Multiple Tables: Subqueries
SELECT SUM (ExtendedPrice) AS Revenue
FROM chapter_2.ORDER_ITEM
WHERE SKU IN
(SELECT SKU
FROM chapter_2.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

37. Querying Multiple Tables: Subqueries (Continued)
SELECT Buyer
FROM chapter_2.SKU_DATA
WHERE SKU IN
(SELECT SKU
FROM chapter_2.ORDER_ITEM
WHERE OrderNumber IN
(SELECT OrderNumber
FROM chapter_2.RETAIL_ORDER
WHERE OrderMonth = 'January'
AND OrderYear = 2004));
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

38. Querying Multiple Tables: Joins
SELECT Buyer, ExtendedPrice
FROM Chapter_2.SKU_DATA, Chapter_2.ORDER_ITEM
WHERE SKU_DATA.SKU = ORDER_ITEM.SKU;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

39. Querying Multiple Tables: Joins (Continued)
SELECT Buyer, SUM(ExtendedPrice)
AS BuyerRevenue
FROM Chapter_2.SKU_DATA, chapter_2.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

40. Querying Multiple Tables: Joins (Continued)
SELECT Buyer, ExtendedPrice, OrderMonth
FROM Chapter_2.SKU_DATA, chapter_2.ORDER_ITEM, chapter_2.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

41. 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

42. 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

43. CHAPTER 1: INTRODUCTION
Oracle SQL
BORDOLOI & BOCK
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

44. SQL
SQL, pronounced ‘Sequel’ or simply S-Q-L, is a computer programming language that was developed especially for querying relational databases using a non-procedural approach.
The term non-procedural means that you can extract information by simply telling the system what information is needed without telling how to perform the data retrieval.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

45. SQL
Extracting information from the database by using SQL is termed querying the database.
SQL is a language that is fairly simple to learn in terms of writing queries, but it has considerable complexity because it is a very powerful language.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

46. DATA AND INFORMATION
Information is derived from raw facts known as data.
Data have little meaning or usefulness to managers unless they are organized in some logical manner.
One of the most efficient ways to organize and manage data is through the use of a database management system (DBMS).
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

47. DBMS
Common 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.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

48. 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.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

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

50. TABLE
In the figure, rows represent records and columns represent fields in a file processing sense.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

51. DATABASE MANAGEMENT SYSTEM
A database management system (DBMS) manages the data in a database.
A DBMS is a collection of programs that enables the users to create and maintain a database.
A DBMS also enables data to be shared; information system users and managers can get more information value from the same amount of data when data sharing occurs.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

52. ORACLE’S RELATIONAL DBMS
Oracle Corporation’s RDBMS is one of the widely used RDBMS products.
An RDBMS performs all the basic functions of the DBMS software along with a magnitude of other functions that make the relational model easier to understand and to implement.
RDBMS provides services that allow information systems professionals to easily change the structure of a database.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

53. ORACLE The significant features of Oracle are: Security mechanisms
Backup and recovery
Space management
Open connectivity
Tools and applications
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

54. SQL AND ORACLE’S SQL*PLUS
Data are manipulated by RDBMS users through the use of special data manipulation language.
Database structures can also be defined by the use of data definition language.
SQL is the most popular database language and has commands that enable it to be used for both manipulation and definition of databases.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

55. SQL
SQL is used by Oracle 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 allows users to manipulate the data in a database.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

56. 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.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

57. SQL*PLUS Through SQL*PLUS users can:
Enter, edit, store, retrieve, and run SQL commands and PL/SQL blocks.
Format, perform calculations on, store, and print query results in the form of reports.
List column definitions for any table.
Access and copy data between SQL databases.
Send messages to and accept responses from an information system user.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

58. RELATIONAL OPERATIONS
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.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

59. The SELECT Statement
The power of SELECT statement comes from its ability to combine data from many tables to produce output in the form of a result table.
A select statement can include or exclude specific columns from one or more tables.
SELECT emp_ssn, emp_last_name
FROM employee;
EMP_SSN EMP_LAST_NAME
Bordoloi
Joyner
Zhu
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

60. Selection Operation
A selection operation selects a subset of rows in a table (relation) that satisfies a selection condition. That subset can range from no rows to all rows in a table.
SELECT emp_ssn, emp_first_name
FROM employee
WHERE emp_ssn = ' ';
EMP_SSN EMP_FIRST_NAME
Douglas
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

61. 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.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

62. 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
Bijoy Bordoloi
Suzanne Joyner
Waiman Zhu
more rows will be displayed . . .
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

63. 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.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

64. 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, emp_dpt_number
FROM employee e, department d
WHERE e.emp_dpt_number = d.dpt_no;
EMP_SSN EMP_FIRST_NAME EMP_LAST_NAME EMP_DPT_NUMBER
Bijoy Bordoloi
Suzanne Joyner
Waiman Zhu
more rows will be displayed . . .
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

65. SQL*PLUS
SQL*PLUS enables the user to manipulate SQL commands and to perform many additional tasks as well.
Through SQL*PLUS, a user can:
Enter, edit, store, and retrieve SQL commands.
Format, perform calculations on, store, and print query results in the forms of reports.
contd
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

66. SQL*PLUS List column definitions for any table.
Access and copy data between SQL databases.
Send messages to and accept responses from a system user.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

67. Starting SQL*PLUS
The most common types used are either the standard Oracle SQL*PLUS available for a Windows-type interface or by connecting to an Oracle database via a telnet session.
The following Log On session is a connection to an Oracle database stored on a Sun Microsystems server running the Unix O/S.
An SQL*PLUS session is begun by typing the command sqlplus at the command prompt($) and entering the username and password information.
contd
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

68. Log-On Screen DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

69. Exiting SQL*PLUS
The SQL*PLUS session can be ended by typing a command at the SQL prompt to terminate the session.
Two commands are available: exit or quit. Either one of these can be used to terminate an SQL*PLUS session.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

70. Running (Executing) a Command File
The command to run (execute) a command file is:
SQL> START filename.sql
A form of shorthand for the word “start” can be used when executing a command file by replacing “start” with (“at” symbol).
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

71. Syntax Conventions
Each select statement must follow precise syntactical and structural rules.
The following is the minimum structure and syntax required for an SQL SELECT statement.
SELECT [DISTINCT | ALL] {* | select_list}
FROM {table_name [alias] | view_name}
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

72. SQL Keywords Keywords are words that have a predefined meaning in SQL.
In practice, keywords may be entered in upper or lower case letters.
SELECT *
FROM employee;
select *
from employee;
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

73. SQL Keywords In some cases keywords can be abbreviated.
The allowed abbreviation is shown in upper case letters with the remainder shown in lower case, which means either the full word or only the upper case part can be used.
DESCribe: can be entered as either DESC or DESCRIBE.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

74. SQL Naming Conventions
Identifiers are the names given by information system developers or system users to database objects such as tables, columns, indexes, and other objects as well as the database itself.
There are several rules for naming database objects that must be followed.
Identifiers should contain between 1 and 30 characters.
The first character must be either alphabetic (a-z, A-Z) or symbol or _ (underscore).
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

75. SQL Naming Conventions
After the first character, digits, letters, or the symbols $, #, or _(underscore) must be used.
No embedded spaces are allowed in identifiers.
SQL keywords cannot be used as an identifier.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall