The document provides an overview of relational database concepts including creation, manipulation, and management of databases. It discusses relational database fundamentals like normalization, SQL, ACID properties, and database systems like MySQL. Examples of SQL queries and preventing SQL injection are also covered at a high level. The document is intended to introduce relational database concepts and technologies.

1. Creation, Manipulation, and Management
Jerome Locson
Developer, Ariba Tech Solutions
me@jeromelocson.com

2.  Graduate from ADZU, BSCS
 PhilNITS FE Passer
 GTUG PH, Zamboanga Chapter Community
Manager
 Technopreneur, Ariba Tech Solutions
 Blog: www.jeromelocson.com

3.  Relational Database Concept
 Structure Query Language (SQL)
◦ DDL, DML and DCL
 Database Normalization
 ACID Property
 Relational Database Management Systems
(RDBMS), MySQL
 Example of MySQL Queries (PhpMyAdmin)
 SQL Injection Prevention

4. ◦ Used by all major commercial database systems
◦ Very simple model
◦ Query with high-level languages: simple yet
expressive
◦ Efficient implementations

5. Schema = structural description of relations in database
Instance = actual contents at given point in time

6. Database = set of named relations (or tables)
Each relation has a set of named attributes (or
columns)
Each tuple (or row) has a value for each attribute
Each attribute has a type (or domain)

7. NULL – special value for “unknown” or “undefined”

8. Key – attribute whose value is unique in each tuple
Or set of attributes whose combined values are
unique

9. ◦ Used by all major commercial database systems
◦ Very simple model
◦ Query with high-level languages: simple yet
expressive
◦ Efficient implementations

10.  Standard/dominant language for accessing
databases and processing
 Steady improvements in reliability,
performance and security
 Applicable to many database systems

11.  It can define a database (DDL)
 It can manipulate database (DML)
 and, can control a database (DCL)

12.  defining the structure and contents of a
relational database
 Metadata (data about the data)
 defines the mapping of database to physical
hardware and devices
 Basic Syntax:
◦ Create Table, Alter Table, Drop Table, Create View,
Create User, etc.

13.  specifies how queries and updates are to be
done
 Basic Syntax:
◦ Select, Insert, Delete, Update

14.  involves configuring and controlling the
database - permission, roles, and referential
integrity
 Basic Syntax:
◦ Grant, Check, Constraint, Primary Key, Foreign Key

15.  Process of efficiently organizing data in a
database (1NF-5NF)
 Too: Entity-Relationship Diagram (ERD)
 Goals:
◦ eliminating redundant data
◦ ensuring data dependencies make sense
 Forms:
◦ 1NF (First Normal Form)
◦ 2NF (Second Normal Form)
◦ 3NF (Third Normal Form)

16.  First normal form (1NF) sets the very basic
rules for an organized database:
◦ Eliminate duplicative columns from the same table.
◦ Create separate tables for each group of related
data and identify each row with a unique column or
set of columns (the primary key).

17.  Second normal form (2NF) further addresses
the concept of removing duplicative data:
◦ Meet all the requirements of the first normal form.
◦ Remove subsets of data that apply to multiple rows
of a table and place them in separate tables.
◦ Create relationships between these new tables and
their predecessors through the use of foreign keys.

18.  Third normal form (3NF) goes one large step
further:
◦ Meet all the requirements of the second normal
form.
◦ Remove columns that are not dependent upon the
primary key.

22.  Stands for atomicity, consistency, isolation,
durability
 set of properties that guarantee database
transactions are processed reliably

23.  Atomicity (atomic)
◦ requires that database modifications must follow an
"all or nothing" rule
◦ If one part of the transaction fails, the entire
transaction fails and the database state is left
unchanged.

24.  Consistency
◦ ensures that any transaction the database performs
will take it from one consistent state to another
◦ only consistent (valid according to all the rules
defined) data will be written to the database
◦ whatever rows will be affected by the transaction
will remain consistent with each and every rule

25.  Isolation
◦ no transaction should be able to interfere with
another transaction at all
◦ use a serial model where no two transactions can
occur on the same data at the same time

26.  Durability
◦ once a transaction has been committed, it will
remain so
◦ every committed transaction is protected against
power loss/crash/errors and cannot be lost by the
system and can thus be guaranteed to be
completed

27.  RDBMS is the basis for SQL, and for all
modern database systems like MS SQL Server,
IBM DB2, Oracle, MySQL, and Microsoft
Access.
 MySQL database is the world's most popular
open source database for the Web
 Supports different languages,
environment, etc.
 www.mysql.com

28. • mysql_connect(host, username
[,password]);
◦ Connects to a MySQL server on the specified host
using the given username and/or password.
Returns a MySQL link identifier on success, or FALSE
on failure.
• mysql_select_db(db_name [,resource])
◦ Selects a database from the database server.

29. • mysql_query(SQL, resource);
◦ Sends the specified SQL query to the database
specified by the resource identifier. The retrieved data
are returned by the function as a MySQL result set.
• mysql_result(result, row [,field]);
◦ Returns the contents of one cell from a MySQL result
set. The field argument can be the field name or the
field’s offset.
• mysql_fetch_array(result [,result_type])
◦ Fetch a result row as an associative array, a numeric
array, or both. The result type can take the constants
MYSQL_ASSOC, MYSQL_NUM, and MYSQL_BOTH.

30. • mysql_free_result(result)
◦ Frees the result set
• mysql_close(resource)
◦ Closes the connection to the database.

31.  If there is error in the database connection,
you can terminate the current script by
using the die function.
 For example:
$db = mysql_connect("localhost", "root“, “”)
or die("Could not connect : " .
mysql_error());
mysql_select_db("my_database")
or die("Could not select database");
$result = mysql_query($query)
or die("Query failed");

32. <?php
/* Connecting, selecting database */
$link = mysql_connect("mysql_host", "mysql_user",
mysql_password")
or die("Could not connect : " . mysql_error());
echo "Connected successfully";
mysql_select_db("my_database") or die("Could not select
database");
/* Performing SQL query */
$query = "SELECT * FROM my_table";
$result = mysql_query($query) Loop through each row
or die("Query failed : " . mysql_error()); of the result set
/* Printing results in HTML */
echo "<table>n";
while ($line = mysql_fetch_array($result, MYSQL_ASSOC)) {
echo "t<tr>n";
foreach ($line as $col_value) { Loop through each
echo "tt<td>$col_value</td>n"; element in a row
}
echo "t</tr>n";
}

33. /* Free resultset */
mysql_free_result($result);
/* Closing connection */
mysql_close($link);
?>

34.  Using mysql_real_escape_string()
 Using of string replace method for SQL
keywords like SELECT, INSERT, DELETE and
UPDATE