Download Narration Script: Slide 1: Oracle Database 11g Express Edition

Narration Script:
Slide 1: Oracle Database 11g Express Edition – Working with Database Objects
Hello and welcome to this online, self-paced course titled Oracle Database 11g Express Edition –
Working with Database Objects. My name is Anupama Mandya, and I am part of Oracle Corporation’s
Curriculum Development team. This course is part of Oracle Database 11g Express Edition New Features
Self-Study series.
In this course, using demonstrations, I will be discussing Working with Database Objects using Oracle
SQL Command Line Utility and Oracle SQL Developer tools. This course is presented in two parts.
Slide 2: Using The Player Script
Before we begin, take a look at some of the features of this Flash-based course player. If you’ve
attended similar Oracle eStudy courses in the past then, feel free to skip this slide.
To your left, you will find a hierarchical course outline. This course enables and even encourages you to
go at your own pace, which means you are free to skip over topics you already feel confident on, or
jump right to a feature that really interests you, or go back and review topics that were already covered.
Simply click on a course section to expand its contents and then select an individual slide. However, note
that by default we will automatically walk you through the entire course without requiring you to use
the outline.
To the right of the course outline tab is the transcripts tab, which contains any additional reference
notes for the current slide. Feel free to read these reference notes at the conclusion of the course. Or if
you prefer you can read them as we go along.
The third tab in the left panel is where you can search for content in this course.
Standard Flash player controls are also found at the bottom of the player, including pause, previous, and
next buttons. There is also an interactive progress bar to fast forward or rewind the current slide.
Interactive slides may have additional controls and buttons along with instructions on how to use them.
To the right of the standard Flash player controls is the Full Screen control. Click on it once to hide the
course outline panel, and click it again to maximize the course display. This may be useful when viewing
videos and demos embedded in the course.
The course will now pause, so feel free to take some time and explore the interface. Then when you’re
ready to continue, click the next button below or alternatively click the next slide in the course outline
on the left.
Slide 3: About This Course
So, you know the title of the course, but you may be asking yourself “Am I in the right place?” To help
you answer these questions you can answer information here regarding the course objectives, target
audience and the prerequisites. When finished, click the “Next Topic” button.
Slide 4 : Road Map
In the first topic, we set up the working environment for this course.
Slide 5: What to do First
First, you need to perform some operations to setup the environment for the topics that follow. This
includes setting up database administration accounts, regular database users and seeding some initial
data into tables in the Express Edition database.
In this topic, you learn how to create administration and database users, and load some employee data
into the Express Edition database.
Create a New Administration Account: An account named SYSTEM is created during the installation
process. This account is considered an administrator account because it has DBA access. Using this
account, you can create your own new administrator account and password so that you can create other
database user accounts when needed. You log in with the administrative accounts to create and manage
other user accounts and to maintain database security.
Create a New Database User Account: You must create at least one database user that you will use to
create database objects. A database user is a type of database object. A user is associated with a
database schema, you connect to the database as a database user, and the database user is the owner
of any database objects (tables and so on) that you create in the schema associated with the user.
Load Data: To seed sample data into 11g Express Edition Database, load a sample script called
load_sample.sql into the database. This is available in the Attachments tab of this course. This script
contains information about each employee and about that employee's department which you might
use to understand and work with the various topics that we will be discussing in this course.
Slide 6: Here are the demonstrations of Creating a New Administration Account and Creating a new
Database User and loading a sample script into the database.
Slide 10: Road Map:
In the next topic, we discuss about Creating and Managing Tables within the Database
Slide 11: Creating and Managing Tables
Oracle Database 11g Express Edition provides an organized mechanism for storing, managing, and
retrieving information. Tables are the basic storage structure for holding business data. You may want to
modify data entered into these tables. You may also want to maintain integrity with the data.
Sometimes, you may want to remove tables that are no longer useful. To do this, statements that
create, change, and drop schema objects are used. These are called Data Definition Language
statements. In this topic, we discuss about Creating and Managing Tables within the database using
these statements.
Overview: Tables are one of the schema objects which are the basic units of data storage in Oracle
Database Express Edition. Tables hold all user-accessible data. Each table contains rows that represent
individual data records. Rows are composed of columns that represent the fields of the records.
Here, the segments around the core represent how to create, modify, manage and remove tables within
the database
Create Tables: A Table is a basic structure to hold user data. The purpose of a table is to hold this user
information in an organized way. The data within the table is stored in rows and columns. You can
create this table using the CREATE TABLE statement
Modify Tables: You may need to change the table structure due to any of the following reasons:
1.You omitted a column.or
2.Your column definition needs to be changed.or
3.You need to remove columns.
To do this, using the SQL ALTER TABLE statement
Manage Constraints: To ensure that the data in your tables satisfies the business rules that your
application models, you use constraints. Constraints restrict the values that columns can have.
Remove Tables: You can discard a table if you no longer find it useful. The DROP TABLE statement
removes the definition of the table from the database.
Slide 12: Create Tables:
About Creating Tables
Moving on, lets take a look about Creating Tables in a bit more detail.
To create tables, you can use either the SQL Developer tool Create Table or the DDL statement CREATE
TABLE.
When creating tables, you must provide:
1. Table name
2. Column name(s)
3. Data types for each column
When you create a table, you must specify the SQL data type for each column. The data type of a
column determines what values the column can contain. For example, a column of type DATE can
contain the value '01-MAY-05', but it cannot contain the numeric value 2 or the character value 'shoe'.
Guidelines for Creating Tables:
Here are some Guidelines for creating tables:
a. Table and column naming rules are
1. It must start with a letter, which is followed by a sequence of letters,numbers,_,#or $ sign
2. It must be 1 to 30 characters long and
3. Must not be an Oracle Server Reserved keyword
b. Most commonly used data types are
VARCHAR
NUMBER
DATE
TIMESTAMP
CHAR
You can also set up constraints on your columns to control the data in them.
Creating a Copy of Tables: You can create a copy of the existing tables using Oracle SQL Developer Copy
tool without affecting the real data.
Slide 13: Following are some demonstrations and simulations about the Create Tables topic where some
procedural tasks are demonstrated in a step-by-step fashion and you are also invited to perform some
steps based on the instructions given to you.
Slide 17: Modify Tables
In this topic, we discuss about Modifying Tables using the SQL Alter statement.
The ALTER TABLE statement is used to:
1.Add a new column
2.Modify an existing column
3.Define a default value for the new column
4.Drop a column and
5.Manage constraints
Adding a New Column: You can add a New Column to an existing table.
In Oracle Database Express Edition, you can modify tables:
Using Oracle SQL Developer or Using the SQL Command Line Utility tools
Slide 18: The following is a simulated demonstration on Modifying Tables. Here an existing EMPLOYEES
database table can be modified by adding the "BirthDate" column. This simulation allows you to perform
step-by-step procedures to add this column using Oracle SQL Developer tool.
Slide 20: Manage Constraints
Ensure Data Integrity in Tables:
In this topic, we discuss about how constraints can be managed in a database table. Data integrity
ensures the consistency and correctness of data stored in a database. Such integrity can be enforced by
incorporating business rules.
Constraints are a set of rules that are enforced on data stored in a table. To ensure that the data in your
tables satisfies the business rules that your application models, you can use constraints. Constraints can
restrict the values that columns can have. Trying to change the data in a way that violates a constraint
causes an error and will undo the change. Trying to add a constraint to a populated table causes an error
if existing data violates the constraint.
You should use constraints to enforce rules on the data in a table whenever a row is updated, inserted
or deleted from that table and to prevent the deletion of a table if there are dependencies from other
tables.
Constraint Types:
The different constraints types are:
1. Not Null, which prevents a value from being null. In the EMPLOYEES table, the column LAST_NAME
has the NOT NULL constraint, which enforces the business rule that every employee must have a last
name
2. Unique, which prevents multiple rows from having the same value in the same column or
combination of columns, but allows some values to be null. In the EMPLOYEES table, the column
EMAIL has the UNIQUE constraint, which enforces the business rule that an employee can have no
email address, but cannot have the same email address as another employee
3. Primary Key, which is a combination of NOT NULL and UNIQUE. In the EMPLOYEES table, the column
EMPLOYEE_ID has the PRIMARY KEY constraint, which enforces the business rule that every
employee must have a unique employee identification number.
4. Foreign Key, which requires values in one table to match values in another table. In the EMPLOYEES
table, the column JOB_ID has a FOREIGN KEY constraint that references the JOBS table, which
enforces the business rule that an employee cannot have a JOB_ID that is not in the JOBS table.
5. Check, which requires that a value satisfy a specified condition. The EMPLOYEES table does not have
CHECK constraints. However, suppose that EMPLOYEES needs a new column, EMPLOYEE_AGE, and
that every employee must be at least 18. The constraint CHECK (EMPLOYEE_AGE >= 18) enforces the
business rule.
6. REF, which further describes the relationship between the column and the object that it references
Creating Constraints: Constraints can be enforced at two levels:
Column level and Table level
A constraint can be created with either of the following statements:
CREATE TABLE or ALTER TABLE
With the ALTER TABLE statement, you can disable or enable the imposed constraint without dropping it
or re-creating it:
You disable a constraint by using the DISABLE clause.
You can enable a constraint by using the ENABLE clause.
Slide 21 : Following is a simulated demonstration on Creating and Managing Constraints. This simulation
allows you to perform step-by-step procedures on how business rules can be enforced on the
EMPLOYEES table using Oracle SQL Developer tool.
Slide 23: Remove Tables
Sometimes it becomes necessary to delete a table and all its contents from your schema. DROP TABLE
results in the removal of the table definition along with the rows.
Tools to Drop Table: There are different ways by which you can drop a table.
To drop a table in Oracle Database 11g Express Edition, use either the SQL Developer navigation frame
and Drop tool, or alternatively use the DDL statement script DROP TABLE
Slide 24: Here is a demonstration of how tables can be removed from the database.
Slide 26: Let us now take a brief pause by taking a Quiz
Slide 28: Moving on to the next topic in this course, we will be discussing about Creating and Managing
other Database Schema Objects
Slide 29: Creating and Managing Other Database Objects
Oracle Database Express Edition groups related information into logical structures called schemas. The
logical structures are called schema objects. When you connect to the database by providing your user
name and password, you specify the schema and indicate that you are its owner. In Oracle Database XE,
the user name and the name of the schema to which the user connects are the same.
Schema objects are logical structures created by users. Apart from tables, there are other objects that
are part of a schema. Some objects, such as tables or indexes, hold data. Other objects, such as views or
synonyms, consist of a definition only. When you create a database object, you must ensure that you
create it in the intended schema.
We have already discussed about creating tables which is a schema object. In this topic, we briefly
discuss the other commonly used schema objects like views, indexes, sequences and synonyms.
Overview: A schema is a collection of database objects. The segments around the core represent the
other database schema objects.
Views: A view presents the output of a query as a table. In most places that you can use a table, you can
use a view.
Indexes: Indexes are optional objects that can improve the performance of data retrieval from tables.
Sequences: Sequences are schema objects that generate unique sequential values, which are very useful
when you need unique primary keys.
Synonyms: A synonym is an alias for another schema object. Some reasons to use synonyms are security
(for example, to hide the owner and location of an object) and convenience.
Slide 30: Creating and Managing Views
In this topic we discuss about views and their uses and also the tools that are available to create and
manage a view. A view is a logical representation of one or more tables. In essence, a view is a stored
query. A view derives its data from the tables on which it is based, called base tables. Base tables can be
tables or other views. All operations performed on a view actually affect the base tables. You can use
views in most places where tables are used.
Views are useful when you need frequent access to information that is stored in several different tables.
You can create a view that combines information from several different tables into a single
presentation. A view can rely on information from both tables and other views. Views enable you to
tailor the presentation of data to different types of users. Views are often used to:
Provide an additional level of table security by restricting access to a predetermined set of rows or
columns of a table and Hide data complexity
For example, a single view can be defined with a join, which is a collection of related columns or rows in
multiple tables. However, the view hides the fact that this information actually originates from several
tables. A query might also perform extensive calculations with table information. Thus, users can query
a view without knowing how to perform a join or calculations.
Present the data in a different perspective from that of the base table
For example, the columns of a view can be renamed without affecting the tables on which the view is
based.
Isolate applications from changes in definitions of base tables
For example, if the defining query of a view references three columns of a four column table, and a fifth
column is added to the table, then the definition of the view is not affected, and all applications using
the view are not affected
Creating a View: You can create views using either the SQL Developer tool Create View or the DDL
statement CREATE VIEW.
To change the name of a view, use either the SQL Developer tool Rename or the RENAME statement.
To drop a view, use either the SQL Developer navigation frame and Drop tool or the DDL statement
DROP VIEW
Slide 31: Following is a demonstration about creating a view using the Create View tool in SQL
Developer
Slide 33: Creating and Managing Indexes
In this topic, you learn about Indexes and their uses. What is an Index? An index is an optional structure,
associated with a table that can sometimes speed data access. By creating an index on one or more
columns of a table, you gain the ability in some cases to retrieve a small set of randomly distributed
rows from the table. Indexes are one of many means of reducing disk I/O.
Indexes are created on one or more columns of a table and are automatically maintained in the
database. When you define a primary key on a table, Oracle Database XE creates a Unique index on the
primary key.
Creating and Dropping an Index: To create an index, use either the SQL Developer tool Create Index or
the DDL statement CREATE INDEX
To drop an index, use either the SQL Developer tool Drop or the DDL statement DROP INDEX.
To change an index, use either the SQL Developer tool Edit Index or the DDL statements DROP INDEX
and CREATE INDEX.
Slide 34: Following is a simulation about creating an index using the Create Index Tool
Slide 36: Creating and Managing Synonyms: In this topic, you learn what Synonyms are their uses and
the different tools that are available to manage Synonyms. You can create a synonym for a table or
view, sequence, PL/SQL program unit, user-defined object type, or another synonym. Because a
synonym is simply an alias, it requires no storage other than its definition in the data dictionary.
Synonyms can simplify SQL statements for database users. Synonyms are also useful for hiding the
identity and location of an underlying schema object. If the underlying object must be renamed or
moved, then only the synonym must be redefined. Applications based on the synonym continue to work
without modification. Some reasons to use synonyms are security (for example, to hide the owner and
location of an object) and convenience.
Examples of convenience are:
■ Using a short synonym, such as SALES, for a long object name, such as CO.SALES_DATA
■ Using a synonym for a renamed object, instead of changing that object name throughout the
applications that use it i.e., if your application uses a table named DEPARTMENTS, and its name changes
to DIVISIONS, you can create a DEPARTMENTS synonym for that table and continue to reference it by its
original name.
Creating and Deleting a Synonym: To create a synonym, you can use either the SQL Developer tool
Create Synonym or the DDL statement CREATE SYNONYM.
To drop a synonym, use either the SQL Developer navigation frame and Drop tool, or the DDL statement
DROP SYNONYM
Slide 37: Following is a demonstration about Creating a Synonym using the Create Database Synonym
Tool
Slide 39: Creating and Managing Sequences
In this topic, we discuss about Sequences and the tools available to create and manage them.
Sequences are schema objects that generate unique sequential values, which are very useful when you
need unique primary keys. When all records of a table must be distinct, you can use a sequence to
generate a serial list of unique integers for numeric columns, each of which represents the ID of one
record. Sequences are used through the pseudo columns CURRVAL and NEXTVAL, which return the
current and next values of the sequence, respectively. After creating a sequence, you must initialize it by
using NEXTVAL to get its first value. Only after the sequence is initialized does CURRVAL return its
current value.
Tip on using a sequence is: When you plan to use a sequence to populate the primary key of a table, give
the sequence a name that reflects this purpose.
A sequence is a schema object from which multiple users can generate unique integers. A sequence
generator provides a highly scalable and well-performing method to generate surrogate keys for a
number data type.
Creating and Deleting Sequences: You can create a sequence using either the SQL Developer tool Create
Sequence or the DDL statement CREATE SEQUENCE.
To drop a sequence, use either the SQL Developer navigation frame and Drop tool, or the DDL statement
DROP SEQUENCE.
Slide 40: Following is a simulation about Creating a Sequence using the Create Database Sequence Tool
Slide 42: Let us now take a brief pause by taking a quiz
Slide 44: Course Review
In this part of the course, we talked about Working with Database Objects which included
•
Creating Database Administration Account
•
Creating User Account
•
Loading Sample Data into the Database
•
Creating and Managing Database Tables and
•
Creating and Managing Other Database Schema Objects
Well, we have now completed the first part. Please refer to the second part to complete this course.
Thank you.