Enforce Referential Integrity
In Microsoft Access 2003, referential integrity rules prevent the creation of orphan records in the table on the many side of the one-to-many relationship. Referential integrity between tables is enforced by default when you create a relationship in your database diagram. While Access enforces this for the user by default, the user can still toggle it on and off. Here are some steps on how to enforce referential integrity in Access 2003.

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Enforce Referential Integrity
Enforcing Referential Integrity for a relationship in a Microsoft Access database can avoid the loss or inadvertent updating of data records.

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Relational Database Design
Part of the definition of a true relational database product is that it supports referential integrity. The principle of referential integrity may be stated as: Every non-null foreign key value must match an existing primary key value. The non-null part means that a value is not required in the foreign key field, but every one that does exist must match a value in the primary key field of the table to which it is related. Referential integrity is all about preserving the validity of foreign key values. Depending upon the product that you are using, you, as the database designer, will usually have to do something to invoke the referential integrity between database tables. It may be as part of the table relationship definition or in the way you join the tables. It is important for you to know how the product that you use enforces referential integrity.

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Relational Database Design
To understand Relational Database table-level or entity integrity, you must understand certain components of a database table. Table-level or referential integrity is managed by the database Jet engine, which establishes rules to maintain table relationships. Understanding table components, and their relationships, is fundamental to complying with the rules of integrity.

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Applying Referential Integrity to a Database
When not properly linked, badly connected tables can cause inefficiency to data retrieval. Eventually the database needs to be fixed by hand, at cost. Data referential integrity is often not well understood in database design. When integrity is not properly applied, it can cause a lot of inefficiency to data retrieval. Eventually the table data needs to be fixed. Duplicate records must be located manually by using queries, and removed. "Orphan" records (due to deleted records) must be repaired.

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Data Integrity
Microsoft Access recognizes parent-child type relationships and embeds methods to ensure that the integrity of these relationships remains valid during your data processing operations. Microsoft Access institutes a system of rules to establish integrity and enforce integrity, once it is established. Integrity can be established for one-to-one or one-to-many relationships during the creation of the relationship or it can be established when modifying existing tables to establish a relationship. The rules of integrity, by default, are designed to prevent the incidence of orphaned table records on the 'many'� side of relationships. As such, Microsoft Access prohibits the deletion of parent records or the modification of primary key values when associated child records exist. If referential integrity is not established, an indeterminate relationship exists between tables.

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Relationships, Referential Integrity, Indexes
How does all the various information relate? What can you do to while you are designing your database to get an overall view? (pdf file, install Acrobat Reader to read this tutorial.)

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Understanding Data Relationships
Access is not restricted, however, in how you can organize your data. It also lets you set up relational databases. In this tutorial, you will learn what a relational database is and how to create one in Access. By the time you finish this tutorial, you will understand the following key concepts: what a relational database is, how information in tables can be related, why keys are important in a relational environment, how to create a relationship between two tables and what referential integrity means.

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Database Primary and Foreign Keys
Primary and foreign keys are the most basic components on which relational database theory is based. Primary keys enforce entity integrity by uniquely identifying entity instances. Foreign keys enforce referential integrity by completing an association between two entities.

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Referential Integrity
At this time, we know that there is useful functionality to creating relations between tables as they allow the user to select existing information instead of typing it. This flow of information brings up issues about what happens if data that exists in a parent table gets deleted while such information has been made available to another table.

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Relational Database Entity Integrity
Entity Integrity ensures that there are no duplicate records within the table and that the field that identifies each record within the table is unique and never null. The existence of the Primary Key is the core of the entity integrity. If you define a primary key for each entity, they follow the entity integrity rule. Entity integrity specifies that the Primary Keys on every instance of an entity must be kept, must be unique and must have values other than NULL.

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Combo Box Controls
A combo box is list of values from which the user can select a single value. Not only does this save typing, it adds another means of enforcing referential integrity since the user can only pick values in the combo box.

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Referential Integrity
At this time, we know that there is useful functionality to creating relations between tables as they allow the user to select existing information instead of typing it. This flow of information brings up issues about what happens if data that exists in a parent table gets deleted while such information has been made available to another table. Learn: Cascades on Related Records, The One-To-Many Relationship, The Many-to-Many Relationship, The One-to-One Relationship, Subdatasheets.

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Domain Level Integrity
A domain defines the possible values of an attribute. Domain Integrity rules govern these values. In a database system, the domain integrity is defined by: The datatype and the length, The NULL value acceptance, The allowable values, through techniques like constraints or rules The default value.

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Getting to Know Access 2003, Part 3
After a brief hiatus, our series explaining the ins and outs of using Microsoft Access 2003 continues. This installment takes you from creating tables to hold data to enforcing referential integrity on those tables. TOC: Getting to Know Access 2003, Part 3; Creating a New Table Without the Wizard; Set the Properties for Your Field; The Primary Key; Relationships.

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Data Integrity Techniques
The database designer is responsible for incorporating elements to promote the accuracy and reliability of stored data within the database. There are many different techniques that can be used to encourage data integrity, with some of these dependant on what database technology is being used. This article will concentrate on the different types of data integrity techniques available whilst working with Microsoft Access

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Relationships
Learn: Basic concepts on relationships, Creating the first relationship, Referential integrity, Adding tables to the relationship window, Removing tables from the relationship window, Editing relationships, Deleting relationships, Tidying the relationship window, Showing direct relationships and Visualizing all the relationships

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Relational Databases
This tutorial covers what many people agree is one of the most difficult database conceptshow to create and work with . A relational database contains two or more tables that are related to each other in some way.For example, a database might contain a Customers table and an Invoices table that contains the customer's orders. In this tutorial you will learn how to link tables in an existing database together in a one-to-many relationship to create a relational database. You will also learn how to enforce referential integrity between those tables to keep records in related fields valid and accurate.

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Build relationships for a new Access 2007 database
Learn how to create relationships among your database tables. Relationships bring the data in your tables together. That enables you to find information and make sound business decisions, and that makes your data powerful. After completing this course you will be able to: 1)Create one-to-many relationships between database tables. 2)Set referential integrity for each relationship and prevent accidental data removal. 3)Set cascading updates and deletes, a move that walks any changes through your data. 4)Turn indexing on or off for primary and foreign key fields, a move that helps speed your database and create a type of relationship called a one-to-one relationship.

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Create, edit or delete a relationship
After you have created a table for each subject in your database, you must provide Office Access 2007 with the means by which to bring that information back together again when needed. You do this by placing common fields in tables that are related, and by defining table relationships between your tables. You can then create queries, forms, and reports that display information from several tables at once. This article provides step-by-step procedures for creating, editing and deleting a table relationship. You will learn how to enforce referential integrity to prevent the creation of orphan records, how to set the join type to determine which records from each side of a relationships are included in a query result, and how to set the cascade options to keep references synchronized.

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Microsoft Office Access 2007: 13 Pages
Contents: Tables and Relationships, Using Related Tables, Types of relationships, Viewing the Relationship window, Adding a Table in the Relationships Window, Setting Referential Integrity, Queries, Using Queries and RecordSets, Using the Simple Query Wizard, Creating a Query in Design View, Opening a Query, Adding a Table to a Query, Running a Query, Sorting a Query, Adding Criteria to a Query, Using Comparison Operators, Using an OR Condition, Creating a Parameter Query, Creating a Calculated Field, Creating Aggregate/Function Query, Creating an Action Query, Using Multiple Tables in a Query. (PDF file, install Acrobat Reader to read this Microsoft Office Access 2007 tutorial)

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Diagramming a Relationship
In the previous lesson, we saw how to establish a relationship between two tables. We also saw that the fields that relate both tables must be of the same data type. To make it possible to visually perform data entry on a table, we learned to create a lookup field. Indeed, this is based on Microsoft Access' high level of support for visual database development. In reality, the only important requirement is that the primary key and the foreign key be of the same data type. In most database scenarios and implementation, the primary key and the foreign key should integer based. As discussed in the previous lesson, the relationship is typically managed through the long integer data. TOC: Diagramming a Relationship, A Sub-Datasheet, Referential Integrity, The One-To-Many Relationship, The Many-to-Many Relationship, The One-to-One Relationship, Inner Joins, Outer Joins.

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Bound controls
So far, the only kind of user interface control you have used on your forms has been the text box. However, ACCESS provides other controls (such as combo boxes, list boxes, check boxes, radio buttons, and so on) that can be used to improve the attractiveness and functionality of your forms. These interface elements are called bound controls because they are bound to fields in the underlying table. When you change data in a bound control, you are changing the data in the underlying table. In this lesson, we are going to focus on a particularly useful bound control: the combo box. A combo box is list of values from which users can select a single value. Not only does selecting from a list save typing, it can be used as a means of enforcing referential integrity since the users choices are (typically) limited to the values in the list. (pdf file, install Acrobat Reader to read this tutorial)

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Event-driven programming
Learning objectives: understand the basic concepts of event driven programming; create a button that executes several actions when pressed; understand the difference between the ACCESS macro language and VBA; use input from users to execute multi step procedures; understand how objects within ACCESS are named.

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Server-side scripting
Learning objectives: create dynamic web pages using, MICROSOFT's ACTIVE SERVER PAGES technology, understand the essentials of server-side scripting, use VBSCRIPT within ASP pages, understand the Response object and how is it used to send information to browsers, understand the Request object and how is it used to receive information from browsers; understand how server-side scripting differs from CGI programming. (pdf file, install Acrobat Reader to read this tutorial).

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Database in MSAccess
A database is a collection of related information or data. Using a database, you can analyze and organize information to understand its significance. Microsoft Access has several components you will need to understand in order to use it: Tables, Queries, Forms, and Reports. Please note this tutorial does not cover relational database design.

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Self Help Documents: Microsoft Access
Topics: understand and create database, import and export data, sort and filter tables, insert graphics, queries, reports, forms, advance table design view, understand relationship and learn how to connect through an ODBC to make tables that you can manipulate in Access. (Download all these tutorial in pdf file format).

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Calculated fields
A calculated field is a "virtual field" in a query. The field is virtual in the sense that it is not stored anywhere in the database. Instead, it is calculated dynamically when the query is used. Learning objectives: create a calculated field; understand why ACCESS add square; brackets around field names; understand the use of the ampersand operator (&). (pdf file, install Acrobat Reader to read this tutorial)

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Key Fields in a Database
Keys are crucial to a table structure for many reasons, some of which are identified below: They ensure that each record in a table is precisely identified. They help establish and enforce various types of integrity. They serve to establish table relationships.

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Customize the Ribbon
The Ribbon - the strip across the top of the program window that contains groups of commands - is a component of the new Microsoft Office Fluent user interface. The Office Fluent user interface provides a single home for commands in Microsoft Office Access 2007 and is the primary replacement for the menus and toolbars in earlier versions of Access. What do you want to do? * Understand Ribbon customization techniques * Create and apply a custom Ribbon * Restore the default Ribbon * Understand the XML example

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Database Design
On the Relational Database Model page, I introduced some of the concepts behind the relational database model. Here we will take a closer look at database normalization, examining both why a database should be normalized and how to do it. We'll then move on to a discussion of data integrity and how to use the database engine to help prevent errors in the data. In the section on indexing, we'll take a look at some different types of indexes and what you should and should not index. Finally, we'll review these topics in the summary.

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Introduction to Data Modeling
Data modeling is the practice of representing data structures and their relationships through conceptual modeling. The benefits of implementing this process during the design phase of your database project include improved data integrity, a more efficient development cycle, a clearer vision of the entities that are being represented in your database, and a powerful visual aid for collaboration and database design.

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Get started with Access programming
When you create a new database, you typically begin by creating a few database objects such as tables, forms, and reports. Eventually, you reach a point where you need to add some programming to automate certain processes and tie your database objects together. This article helps orient you to the programming tools in Microsoft Office Access 2007 and points you to some resources where you can learn more about programming. In this article: What is programming? Should I use macros or should I use VBA code? Use the Command Button Wizard to perform common programming tasks, Understand macros, Understand VBA code, Convert macros to VBA code, Learn how to use the Help system.

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Free Access 2007 Tutorial
Access 2007 is the database software in the Microsoft 2007 Office Suite. It allows you to order, manage, search, and report large amounts of information. This tutorial will show you how to build a database from scratch, including how to plan and set up tables and fields, create and use forms to enhance data integrity, design and run meaningful queries, and create useful and attractive reports.

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Access SQL: basic concepts, vocabulary, and syntax
When you want to retrieve data from a database, you ask for the data by using Structured Query Language, or SQL. SQL is a computer language that closely resembles English, but that database programs understand. Every query that you run uses SQL behind the scenes. Understanding how SQL works can help you create better queries, and can make it easier for you to understand how to fix a query that is not returning the results that you want. This is one of a set of articles about Access SQL. This article describes the basic use of SQL to select data, and uses examples to illustrate SQL syntax. In this article * What is SQL? * Basic SQL clauses: SELECT, FROM, and WHERE * Sorting the results: ORDER BY * Working with summarized data: GROUP BY and HAVING * Combining query results: UNION

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Create a grouped or summary report
Information is often easier to understand when it is divided into groups. For example, a report that groups sales by region can highlight trends that otherwise might go unnoticed. In addition, placing totals at the end of each group in your report can replace a lot of manual interaction with a calculator. Microsoft Office Access 2007 makes working with grouped reports easy. You can create a basic grouped report by using the Report Wizard, you can add grouping and sorting to an existing report, or you can revise grouping and sorting options that have already been defined. In this article * Understand grouping, report sections, and controls * Build a new grouped report by using the Report Wizard * Fine-tune your report * Add fields or controls to an existing report * Add or modify grouping and sorting in an existing report * Save, print, or send your report * Remarks

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FORMS AND TABLES
I need a combo box to be able to lookup a list of names and the text boxes to equal the address of that name once that is done then for this detail to be placed into another table if you can understand this help would be appreciated

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Relationships and Data Integrity
When performing data entry, a user's job should be as easy and smooth as possible. One of the aspects that take care of this is the flow of information from one list to another. In other words, data stored in one list can be made available to another list so the user not only doesn't have to enter the same piece of information in different lists but also the should be able to access, from one list or table, data stored in another table. To allow the information to flow from one list to another, there should (must) exist a relationship between both tables. A relationship is made possible through a type of link from one table to another. This is the essence of relational databases.

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MS Access tutorials for beginners
Helps you learn and understand MS Access database systems.

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Nulls: Do I need them?
Introduction to how to work with Nulls in a Microsoft Access database: why you need them, what they are, and how to understand them.

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