ch02 access

Building The Database

1

Chapter 2

“It is only the farmer who faithfully plants seeds in the Spring, whoreaps a harvest in the Autumn.” —BC Forbes

XPXPChapter Introduction• Learn different techniques for

– Creating tables – Entering data – Verifying data– Relating tables– Documenting database objects – Backing up database– Repairing database– Securing data

Succeeding in Business with Microsoft Office Access 2007: A Problem-Solving Approach 2

XPXPTools Covered in This Chapter• Datasheet view• Design view• Documenter• Import spreadsheet wizard• Input mask wizard

• Lookup Wizard• Relationships window• Database Security• Subdatasheet• Table Templates


XPXPLevel 1 Objectives: Creating the Database Tables• Create a database and tables• Work in Design view• Set a field’s data type size and properties• Use the Input Mask Wizard and the Lookup

Wizard• Validate fields


XPXPUsing the Database Design to Create the Database• Blank Database option in the Getting Started

Screen• Database window

– Main control panel for database


XPXPCreating a Table by Entering Data• Click Create tab, and then click Table• Datasheet view

– Shows table’s records in rows and table’s fields in columns

• Table window– Indicates table’s name

• Just start entering data• Access adds ID field to datasheet


XPXPDatasheet View


XPXPCreating a Table by Entering Data (continued)• Click save button

– Save as dialog box– Enter table name

• Change to design view– Click view button on the Home tab


XPXPWorking in Table Design View• Design view

– Define table’s fields and field properties – Rearrange order of fields as necessary

• Table design grid– Top part of design view– Includes field name data type and description

columns– Each row

• Field in table


XPXPWorking in Table Design View (continued)• Field properties pane

– Bottom part of design view– Displays field properties for selected field

• Rules when naming fields and database objects– Up to 64 characters– Any combination of

• Letters• Numbers• Spaces• Special characters except ., !, `, [, and ]


XPXPWorking in Table Design View (continued)• Rules when naming fields and database objects

– Cannot begin with space• Some organizations establish standards for

naming objects and fields• Field size property

– Limit number of characters to store in text field – Type of numeric data to store in number field


XPXPAdding Descriptions to Fields in Table Design View• Description property

– Document contents – Identify field as primary or foreign key – Provide users with instructions about entering values

into field• Primary key button


XPXPCreating a Table Using the Table Templates• Table Templates

– Includes sample tables for business and personal needs

– Select and modify fields to create tables• Good method to use when

– Table already exists as sample table– Accept default field properties assigned to fields in

template or easily change them


XPXPTable Template


XPXPCreating a Table in Design View• Click Design button on Create tab• Enter field names and data types


XPXPEvaluating and Testing the Table Design• By moving to next record

– Access saves record in table– To cancel record

• Press Esc key

• After designing table– Evaluate for potential problems


XPXPDisplaying Descriptive Field Names Using the Caption Property• Caption property

– Change way field name displayed– Specifies how field name will appear in different

database objects– Default caption property

• Field name for all data types


XPXPFormatting Field Values Using an Input Mask• Input mask

– Predefined format – Applied to field – Values are displayed using format specified– Ensures that all of necessary data entered

• Literal characters– Not stored in database– User does not need to type them

• Input Mask Wizard


XPXPInput Mask Characters and Descriptions


XPXPValidating Fields to Ensure Accurate and Consistent Data• Validation rule

– Compares data entered by user against one or more valid values

• Validation Rule property – Specifies valid values that users can enter

• Validation Text property– Displayed if user enters invalid value


XPXPSample Validation Rules and Validation Text


XPXPAutomating Data Entry by Using a Default Field Value• Default Value property

– Enters default value into any type of field – Except for AutoNumber field


XPXPAutomating Data Entry by Using a Lookup Field• Lookup field

– Lets user select field value – From

• List of existing field values stored in database • List of values specified when lookup field created

• Change field’s data type in Lookup Wizard


XPXPLevel 1 Summary• Create tables by

– Entering data– Using design view– Create table templates

• Customizing tables– Captions– Validation rules– Using lookup wizard


XPXPLevel 2 Objectives:Populating and Relating the Database Tables• Import data into a database• Set a table’s primary key• Create foreign keys• Create one-to-many and many-to-many

relationships• Use a subdatasheet to view related records in a

table


XPXPPopulating the Database Tables• Populating database

– Load tables with data– Enter data in datasheets– Import data


XPXPCopying Records from One Table to Another• Import existing data from another table

– Table structure must be identical– Select all of records– Click copy button– Open target database table– Click paste button

• Correct errors with AutoNumber field record numbers that should be incremented sequentially– Delete AutoNumber field from table– Add it back


XPXPImporting Data from an Excel Workbook• Can import data and create table at same time

– Review contents of workbook to understand how it is arranged

• If column heading names comply with rules for naming fields in access – Access uses them as field names data imported

• If column headings absent or do not comply– Access assigns generic field names


XPXPImporting Data from an Excel Workbook (continued)• Access can import most data from worksheet

– Not graphics– Formulas converted to numbers– Hyperlinks imported as text data

• Usually entire worksheet imported– Can import range of data


XPXPImport Spreadsheet Wizard


XPXPSetting a Primary Key Field


XPXPWorking with Primary and Foreign Keys• Primary key and foreign key counterparts

– Must have same data type and field size – Fields must contain identical values

• Primary key value must exist before entering corresponding record– If referential integrity set

• User cannot enter null value into primary key field• Required property

– Nonprimary key field– Ensure that users enter value into field


XPXPWorking with Primary and Foreign Keys (continued)• Works to make data retrieval faster

– Access creates index for primary key field• Index

– List maintained by database– Associates field values in indexed field with records

that contain field values


XPXPCreating an Index• Increase speed at which access searches• Open table in design view

– Select field to index– Click indexed property list arrow

• Create index for any field– Except fields of type

• Memo• Hyperlink• OLE object


XPXPCreating an Index for a Nonprimary Key Field


XPXPCreating an Index• View indexes created in table

– Click indexes button on Table Design tab• Create indexes for as many fields as necessary to

optimize searches in database• Records indexed when table saved• Updated automatically as records added deleted,

or changed • As database grows

– Indexes might slow down database


XPXPCreating an Index (continued)• Increases size of database • Slows down database

– Must update index as users add change and delete records

• Add indexes as needed – When improved performance necessary

• Delete indexes to– Increase speed – Reduce file size


XPXPCreating One-to-Many Relationships Between Tables• Open relationships window

– Click relationships button on Database Tools tab• Relationship has certain properties

– Type• One-to-many• One-to-one• Many-to-many

– Attributes • Specify how to manage changes when records updated or

deleted


XPXPRelationships Window


XPXPEdit Relationships Dialog Box


XPXPCreating a Many-to-Many Relationship Between Tables• Use junction table to create many-to-many

relationship• Create 1:M relationships between both tables

and junction table


XPXPUsing a Subdatasheet to View Related Records• After importing data into database

– Good idea to open each table in Datasheet view – Check data for problems

• Plus box appears for relationships– Click to view subdatasheet


XPXPLevel 2 Summary• Import data from

– Other Access tables– Excel

• Index– Used to aid searches

• Create relationships using Relationships Window


XPXPLevel 3 Objectives:Maintaining and Securing a Database• Learn about the role of the database

administrator• Compact repair and back up a database• Document the database design using the

documenter• Secure a database by setting a password

encrypting data, and hiding objects• Create user-level security in a database


XPXPThe Database Administrator Role• Database administration (DBA)

– Responsible for maintaining database– Sets security and other features of database

• Default option for opening database– Available to other users at same time

• Open access database in four ways– Open mode– Open read-only mode– Open exclusive mode– Open exclusive read-only mode


XPXPCompacting and Repairing a Database• Compact

– Data and objects reorganized– Unused spaces reassigned and deleted– Result

• Decreased file size • Improved efficiency

– Can be done manually or every time database closed• Good idea to compact before backing up


XPXPBacking Up a Database• Creates copy of database

– Use to restore in event of loss

• Schedule database backups based on manageable amount of data loss

• Important to store copy in fireproof location offsite• Created on external media such as

– CD – DVD– External hard drive


XPXPBacking Up a Database (continued)• Back up database

– Click Office button– Point to Manage– Click back up database

• Default backup database name– Original database name followed by current date

• Might few minutes to several hours to backup– Depends on database size

• Backup copy can be opened like any other Access database


XPXPDocumenting the Database Design• Documenter tool

– Produces report of every object or just selected objects in database

• Click Database Tools tab, and then click the Database Documenter button– Tabs at top of documenter dialog box – Sort objects by type


XPXPDocumenter Dialog Box


XPXPSecuring a Database From Unauthorized Use• Plan for and prevent data loss• Protect database from unintentional or malicious

damage• DBA must open database with exclusive access

prior to setting protection features• Tools

– Setting database password– Encrypting database– Hiding database objects


XPXPUsing a Password to Protect a Database• Password

– Collection of characters that user types to gain access to file

• Database administrator sets database password – Users cannot open database file in access – Unless they provide correct password


XPXPEncrypting a Database to Prevent Unauthorized Use• If someone steals file and tries to open it with

program other than access– Password will not protect file

• Encrypting database – Converts data in database into format readable only

by Access• Click the Encrypt with Password button on the

Database Tools tab on the Ribbon


XPXPHiding Database Objects From Users• Casual users may damage database by

– Unintentionally altering object’s design – Deleting object entirely

• Hide objects from being displayed in database window– User will not be able to accidentally or intentionally

damage database• Revealing hidden object not difficult• Hide using properties dialog box


XPXPLevel 3 Summary• Compact database• Backup database• Document database• Secure database

– Password– Encryption– Hiding objects


XPXPChapter Summary• Create tables using one of three methods• Import data from

– Other Access tables– Excel

• Create relationships using Relationships Window• Secure database using:

– Password– Encryption– Hiding Objects


ch02 access

Documents

microsoft office access

problemsolving approach

database design

design viewincludes

id field

design viewclick design

table templatesucceeding

table designby