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Introduction to PL/SQL
Oracle Database PL/SQL 10g Programming
Chapter 1 & 2
Introduction to PL/SQL
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SQL*Plus Environment
Development Environments
Database Design Concepts
SQL Concepts
PL/SQL Language
Oracle Database PL/SQL 10g Programming
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Introduction to PL/SQL
SQL*Plus Environment
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The interactive and batch processing environment for SQL and
PL/SQL statements.
Command line interface to Oracle.
The connection and session environment:
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Interactive scripting.
Batch execution using silent option.
Session environment when connecting by using OCI, ODBC and JDBC
external programming models.
Supports formatting commands.
Supports session scope variables, also known as bind variables.
Supports a GUI versions for Microsoft Windows, which is being
deprecated.
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Introduction to PL/SQL
SQL*Plus Environment
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SQL*Plus is run by using the sqlplus executable on Microsoft Windows,
Linux or Unix.
SQL*Plus supports option flags:
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sets command compatibility to current or older version.
provides help screen.
sets the log on attempts to a number other than the default 3.
lets you set a series of HTML formatting options.
restricts user interaction with the file system.
sets silent mode for batch processing by suppressing console feedback.
returns the version.
SQL*Plus supports different connection models:
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-c
-h
-l
-m
-r
-s
-v
DBA Administration connections using “/ AS SYSOPER” or “/ AS SYSDBA”.
Default connection, which enables a user to connect to a schema and database.
Open environment not conneted to a database using “/NOLOG” mode.
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Introduction to PL/SQL
SQL*Plus Environment
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SQL*Plus connection samples:
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sqlplus –h | -v
sqlplus username/password[@sid]
sqlplus –s username/password[@sid] @script.sql
SQL*Plus commands do not require semicolons to run.
SQL*Plus redirects output to files with a default .lst extension:
SQL> spool C:\mydir\myoutputfile.log
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SQL*Plus runs files from local or qualified directories using the @
symbol:
SQL> @C:\mydir\myfile.sql
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SQL*Plus runs scripts with a .sql extension when the extension is
excluded.
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Introduction to PL/SQL
SQL*Plus Environment
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SQL*Plus can edit the current buffer:
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SQL*Plus can edit a file:
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Microsoft is preconfigured, you need only type:
SQL> ed
Linux or Unix requires:
SQL> define _editor=vi
SQL> ed
Microsoft is preconfigured, you need only type:
SQL> ed C:\mydir\myfile.sql
Linux or Unix requires:
SQL> define _editor=vi
SQL> ed C:\mydir\myfile.sql
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Introduction to PL/SQL
SQL*Plus Environment
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SQL*Plus has many environment variables:
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SQL*Plus common requirements:
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You can find the default settings by:
SQL> show all
You change many environment variables by:
SQL> set echo on | off
You set some environment variables by providing a value:
SQL> set sqlpluscompatibility 9.2.0
You set some environment variables by providing a delimited value:
SQL> set null “<null>”
SQL> set suffix “pls”
Suppress column headers:
SQL> set pagesize 0
Enabling maximum standard out redirection from PL/SQL:
SQL> set serveroutput on size 1000000
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Introduction to PL/SQL
SQL*Plus Environment
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SQL*Plus can read only a file into the buffer:
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You use the GET command.
You cannot run the file without errors if there are SQL*Plus commands
in it.
You should use the @ command to read and execute a script when it
contains SQL*Plus commands.
SQL*Plus supports global session variables, also known as bind
variables, and they must be SQL types not subtypes, like:
BINARY_DOUBLE
BINARY_FLOAT
CHAR (n char | byte)
CLOB
NUMBER
REF CURSOR
VARCHAR (n char | byte)
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Oracle Database PL/SQL 10g Programming
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Introduction to PL/SQL
SQL*Plus Environment
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SQL*Plus global session variables:
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Are declared in SQL*Plus.
Are defined in PL/SQL program units.
SQL*Plus declares a global session variable using the
following syntax:
SQL> variable mynum NUMBER
SQL> variable mystr VARCHAR2(10)
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SQL*Plus defines the global session variables in PL/SQL
program units, which can be:
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Anonymous block programs, or
Named block programs.
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Introduction to PL/SQL
Development Environments
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SQL*Plus is the interface to the
database.
SQL runs inside of the SQL*Plus
environment.
PL/SQL runs inside of the SQL
environment.
Oracle development in SQL & PL/SQL
is also supported by external
Integrated Development Environments
(IDEs).
External programs connect through
the SQL*Plus environment.
User-defined libraries are declared by
SQL.
User-defined libraries are wrapped by
PL/SQL named blocks.
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Oracle
SQL*Plus
Connect
SQL
Standard
Libraries
ODBC
PL/SQL
User
Libraries
JDBC
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Introduction to PL/SQL
Development Environments
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Oracle PL/SQL Development is supported by:
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IDE tools provide:
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Oracle SQL*Plus
Oracle JDeveloper.
Oracle SQL Developer.
Oracle Application Developer.
Quest Software’s Toad Developer.
Diagnostic tools.
Debugging tools.
Syntax auto fill tools.
Syntax highlighting.
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Introduction to PL/SQL
Development Environments
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The Oracle Transparent Network Substrate (TNS) implements an
application layer of the OSI model.
Users connect through TNS to the database using TCP sockets
or IPC connections.
Clients use the tnsnames.ora file like a host file, and map
machine names to a combination of IP and port address.
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The Oracle server listens on a port for incoming TNS requests,
and uses three configuration files:
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Net service name resolves to machine name and port number.
The service name in the tnsnames.ora file maps to the Oracle
database SID value.
listener.ora
sqlnet.ora
tnsnames.ora
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Introduction to PL/SQL
Development Environments
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Oracle PL/SQL development is supported by:
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IDE tools provide:
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Oracle SQL*Plus
Oracle JDeveloper.
Oracle SQL Developer.
Oracle Application Developer.
Quest Software’s Toad Developer.
Diagnostic tools.
Debugging tools.
Syntax auto fill tools.
Syntax highlighting.
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Introduction to PL/SQL
Database Design Concepts
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Database Tables are:
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2-dimensional arrays of rows and columns.
Columns can hold a scalar or compound variable:
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Scalar variables hold only one thing at a time.
Compound variables hold:
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Normalized tables with a primary key.
Normalized tables with one or more foreign keys.
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Foreign keys hold a copy of a primary key in another table.
Foreign keys hold a copy of a primary key in the same table.
Normalized tables with one or more superkey:
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A list of one thing, which can be scalar or compound.
A structure, which is also known as a record.
Super keys identify one or more rows in a table.
Super keys identify one row in a relation.
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Introduction to PL/SQL
Database Design Concepts
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Database Tables hold data.
Database Tables have a binary or n-ary
relationships:
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Binary relations exist between two tables and are:
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N-ary relations exist between three or more tables
and are:
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One-to-one
One-to-many
Many-to-many between two tables.
Typically many-to-many
Occasionally one-to-many.
Rarely one-to-one.
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Introduction to PL/SQL
Database Design Concepts
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Database tables are normalized in:
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3rd or higher normal form
Domain Key Normal Form (DKNF):
DKNF uses a surrogate key, also known as
automatic numbering.
 DKNF cannot use a natural key.
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Database tables have constraints on
column values.
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Introduction to PL/SQL
Database Design Concepts
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Unique:
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A unique constraint tells the database to
disallow a column to hold two or more equal
values, and typically made using “out-of-line”
constraint syntax.
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Introduction to PL/SQL
Database Design Concepts
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Not null:
 A not null constraint tells the database to
disallow entry of a null value into the column
from an INSERT or UPDATE statement, a not
null constraint must be made using “inline”
syntax or it is a check constraint.
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Introduction to PL/SQL
Database Design Concepts
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Check:
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A check constraint tells the database to
disallow entry or update of a column value
that fails to meet the expression governing
the constraint, and is typically made using
“out of line” constraint syntax.
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Introduction to PL/SQL
Database Design Concepts
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Primary key:
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A primary key tells the database to allow
entry or update of a column value that is only
both unique and not null, and it enables a
foreign key constraint to reference the column
or set of columns defined as the primary key,
and typically made using “out-of-line”
constraint syntax.
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Introduction to PL/SQL
Database Design Concepts
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Foreign key:
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A foreign key constraint tells the database to
disallow entry or update of a column value
that is not found in the referenced primary
key column list of values, and typically made
using “out-of-line” constraint syntax.
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Introduction to PL/SQL
SQL Concepts
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Structured Query Language (SQL)
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ANSI Standards
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Structured English QUEry Language (SEQUEL)
ANSI
ANSI
ANSI
ANSI
ANSI
SQL-86
SQL-89
SQL-92
SQL:1999
SQL:2003
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Introduction to PL/SQL
SQL Concepts
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Security is tiered by ANSI-SPARC rules
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Superuser grants privileges to users
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Superuser – holds internal data
Administrator – holds conceptual data
User – holds external data
Grants individual privileges one at a time.
Creates roles as groups of privileges.
Grants grouped privileges as roles.
Data can be restricted at various levels
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Introduction to PL/SQL
SQL Concepts
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Data Control Language (DCL)
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Data Definition Language (DDL)
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Creates or modifies data structures in the database.
Uses the ALTER, CREATE, DROP, FLASHBACK, GRANT, PURGE,
RENAME, REVOKE, and TRUNCATE commands.
Uses the recycle bin in Oracle 10g Release 2.
Data Manipulation Language (DML)
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Manages transaction controls.
Uses the COMMIT, ROLLBACK, and SAVEPOINT commands.
Inserts, updates and deletes data from tables.
Uses the INSERT, UPDATE, and DELETE commands.
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Introduction to PL/SQL
PL/SQL Language
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Procedural Language/Structured Query Language (PL/SQL)
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PL/SQL Legacy
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Derived syntax from Ada programming language.
Inherited operators and structure from Pascal through Ada.
PL/SQL Block Structure
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Introduced in Oracle 6 as a report formatting language.
Improved to a useful programming language in Oracle 7.
Improved to include collections in Oracle 8.
Improved to include instantiable object types in Oracle 9i Release 2.
Improved to include conditional compilation in Oracle 10g.
Implemented as a strongly typed language.
Implemented as a formal blocked language.
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Introduction to PL/SQL
PL/SQL Language
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PL/SQL Integration
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Tightly integrated with SQL.
Shares SQL data types.
Includes PL/SQL only data types.
Enables user-defined data types.
Interface between external procedures and SQL*Plus.
Interface between external libraries and SQL*Plus.
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Introduction to PL/SQL
PL/SQL Language
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PL/SQL Advanced Features
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Full object-oriented programming is available from Oracle 9i
Release 2.
Full support for dynamic SQL.
Full support for pass-by-value and pass-by-reference models.
Full support for wrapping solutions in other programming
languages.
Full catalog definitions act like OO class files.
Robust extensions made through built-in packages.
Conditional compilation available in Oracle 10g Release 2.
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Summary
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SQL*Plus Environment
Development Environments
Database Design Concepts
SQL Concepts
PL/SQL Language
Oracle Database PL/SQL 10g Programming
(Chapter 1 & 2)
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