Archive for the 'Zend' Category


The basic principles of relational database design. Part 6

Tuesday, July 15th, 2008

<< Part 5

Source: Database Design for Mere Mortals: A Hands-On Guide to Relational Database Design by Michael J. Hernandez

Elements of a Foreign Key

  1. It has the same name as the Primary key from which it was copied.
  2. It uses a replica of the field specifications for the Primary key from which it was copied.
  3. It draws its value from the Primary key to which it refers.

Establishing a Deletion Rule for Each Relationship

  1. Restrict. The requested record cannot be deleted if there are related records.
  2. Cascade. The requested record will be deleted as well as all related records.

Identifying the Type of Participation for Each Table

  1. Mandatory. There must be at least one record in this table before you can enter any records into the other.
  2. Optional. There is no requirement for any records to exist in this table before you can enter any records into the other table.

Relationship-Level Integrity

  1. Made certain that the connection between two tables in a relationship is sound.
  2. Ensured your ability to insert new records into each table in a meaningful manner.
  3. Ensured your ability to delete an existing record without creating adverse affects.
  4. Established a meaningful limit to the number of records that can be interrelated within the relationship.

What Are Business Rules?

A business Rule is statement that imposes some form of constraint on elements within a field specification for a particular field or on characteristics of a relationship between a specific pair of table.

Examples:

  • A Ship Date cannot be prior to an Order date for any given order.
  • A student cannot have more than two instruments checked out at the same time.

Types of Business Rules

  1. Database-oriented Business Rules are those that impose constraints that can be established within the logical design of the database.
  2. Application-oriented Business Rules are those that impose constraints that cannot be established by modifying a Field Specification or relationship diagram.

Determining and Establishing Views

There are three categories of Views: date Views, aggregate Views, and validation Views.

  1. Data Views are used to examine and manipulate data from base tables.
  2. Aggregate Views are used to display information that is the result of aggregating a particular set of data in a specific manner.
  3. Validation Views are used to implement data integrity. When a Business Rule limits the range of values of a particular field, you can enforce the constraint just as easily with a validation View as you can with a validation table.

Using a View Specifications Sheet to Record the View

Reviewing and Refining Data Integrity

  1. At the table level:
    There are no duplicated fields in the table.
    There are no calculated fields in the table.
    There are no multi-valued fields in the table.
    There are no multipart fields in the table.
    There are no duplicated records in the table.
    Every record in the table is identified by a Primary key value.
    Each Primary key conforms to the Elements of a Primary key.
  2. At the field level:
    Each field conforms to the Elements of the Ideal Field.
    A set of Field Specifications has been defined for each field.
  3. At the relationship level:
    The table relationship is properly established.
    The appropriate deletion rule has been established.
    The type of participation has been correctly identified.
    The proper degree of participation has been established.
  4. At the level of business rules:
    Each rule imposes a meaningful constraint.
    The proper category has been determined for the rule.
    Each rule is properly defined and established.
    The appropriate Field Specification elements or table relationship characteristics have been properly modified.
    The appropriate validation tables have been established.
    A Business Rule Specification sheet has been completed for each rule.
  5. At the level of views:
    Each View contains the base tables necessary to provide the required information.
    Each View has been assigned the appropriate fields.
    Each calculated field provides pertinent information or enhances the manner in which the data is displayed.
    Each filter returns the appropriate set of records.
    Each View is accompanied by a View Specification sheet.

Assembling the Database Documentation

  1. Final table list.
  2. Relationship diagrams
  3. Field Specifications sheets.
  4. Business Rule Specifications sheets.
  5. Calculated field list.
  6. View diagrams.
  7. Table structure diagrams.
  8. View Specifications sheets.

<< Part 5


4th Annual Zend/PHP Conference – ZendCon

Tuesday, July 8th, 2008

The 4th Annual Zend/PHP conference will bring together PHP developers and business managers from around the world for three days of exceptional presentations and networking events.

The theme of this year’s conference is “High Impact PHP” and sessions will explore the many ways that PHP developers and application managers deliver breakthrough design, functionality, performance and scalability in new web applications, resulting in real business advantage for their companies.

MORE THAN 60 SESSIONS

ZendCon 2008 will offer more than 60 technical sessions, tutorials and case studies designed to benefit architects, developers, system administrators and business managers at all levels of experience with PHP. Sessions will highlight details of new innovations for creating, operating and managing applications that leverage the speed, scalability and simplicity of PHP. Conference speakers for this year’s conference include PHP luminaries like Marcus Börger, Sebastian Bergmann, Chris Shiflett, Jay Pipes and many others.

These key members of the PHP Community will deliver sessions in the following conference tracks:

  • PHP Business Cases
  • Best Practices
  • The Basics of PHP
  • Advanced PHP Topics
  • Performance and Scalability
  • Rich Internet Applications
  • Zend PHP on i5/OS
  • Zend Framework

View complete conference schedule »

BACK BY POPULAR DEMAND: UNCONFERENCE SESSIONS

For the second consecutive year, we are pleased to offer the ZendCon UnCon to attendees. We try our best to make sure that all topics are covered at ZendCon but we know that we will miss some of interest to the group. The UnCon was designed to present a forum for attendees who share an interest in other PHP topics.

If you are attending ZendCon and want to present or host a topic, we will ask you to submit a request on the conference wiki »

FREE PHP 5 CERTIFICATION EXAM

Attendees at the 2008 Zend/PHP Conference will have the opportunity to take the Zend PHP 5 certification exam for free (a $125 value)!
The tutorials on September 15, 2008 will include a certification crash course that will help prepare you for the exam. Please note that testing spaces are limited and registration will be accommodated on a first-come, first-served basis.

See Certification test and tutorials schedule »

REGISTER NOW AND SAVE UP TO $300

Registration for the 2008 Zend/PHP Conference is now available. If you register before July 25, 2008, you will be able to save up to $300 with the early registration discount. Additional discounts are available for Zend Certified Engineers and multiple registrants. If you have any questions, please contact zendcon@zend.com.
Register for ZendCon 2008 »

I hope that you will join us in September for the largest gathering of the PHP Community!