Modifying the Database Structure

Objectives Examine relational databasesExamine relational databases Design related tablesDesign related tables Create one-to-many relationshipsCreate one-to-many relationships Create Lookup fieldsCreate Lookup fields Modify Short Text fieldsModify Short Text fields Microsoft Office 2013-Illustrated2

Objectives Modify Number and Currency fieldsModify Number and Currency fields Modify Date/Time fieldsModify Date/Time fields Modify validation propertiesModify validation properties Create Attachment fieldsCreate Attachment fields Microsoft Office 2013-Illustrated3

Examining Relational Databases The purpose of a relational database is to organize and store data in a way that minimizes redundancy and maximizes your flexibility when querying and analyzing dataThe purpose of a relational database is to organize and store data in a way that minimizes redundancy and maximizes your flexibility when querying and analyzing data Microsoft Office 2013-Illustrated4

Examining Relational Databases To redesign a list into a relational database:To redesign a list into a relational database: Design each table to contain fields that describe only one subjectDesign each table to contain fields that describe only one subject Identify a primary key field for each tableIdentify a primary key field for each table Build one-to-many relationshipsBuild one-to-many relationships 5Microsoft Office 2013-Illustrated

Examining Relational Databases 6Microsoft Office 2013-Illustrated

Designing Related Tables After you develop a valid relational database design, you are ready to define the tables in Access.After you develop a valid relational database design, you are ready to define the tables in Access. Using Table Design View, you can specify all characteristics of a table including field names, data types, field descriptions, field properties, Lookup properties, and primary key field designations.Using Table Design View, you can specify all characteristics of a table including field names, data types, field descriptions, field properties, Lookup properties, and primary key field designations. 7Microsoft Office 2013-Illustrated

Designing Related Tables 8Microsoft Office 2013-Illustrated

Creating One-to-Many Relationships After creating the tables you need, you link them together in appropriate one-to-many relationships using the primary key field in the “one” table and the foreign key field in the “many” table.After creating the tables you need, you link them together in appropriate one-to-many relationships using the primary key field in the “one” table and the foreign key field in the “many” table. To avoid rework, be sure that your table relationships are finished before building queries, forms, or reports using fields from multiple tables.To avoid rework, be sure that your table relationships are finished before building queries, forms, or reports using fields from multiple tables. 9Microsoft Office 2013-Illustrated

Creating One-to-Many Relationships 10Microsoft Office 2013-Illustrated

Creating Lookup Fields A Lookup field is a field that contains Lookup properties.A Lookup field is a field that contains Lookup properties. Lookup properties are field properties that supply a drop-down list of values for a field.Lookup properties are field properties that supply a drop-down list of values for a field. The values can be stored in another table or directly stored in the Row Source Lookup property of the field.The values can be stored in another table or directly stored in the Row Source Lookup property of the field. You can set Lookup properties for a field in Table Design View using the Lookup Wizard.You can set Lookup properties for a field in Table Design View using the Lookup Wizard. 11Microsoft Office 2013-Illustrated

Creating Lookup Fields 12Microsoft Office 2013-Illustrated

Modifying Short Text Fields Field properties are the characteristics that describe each fieldField properties are the characteristics that describe each field Field SizeField Size Default ValueDefault Value CaptionCaption Row SourceRow Source These properties help ensure database accuracy and clarityThese properties help ensure database accuracy and clarity 13Microsoft Office 2013-Illustrated

Modifying Short Text Fields 14Microsoft Office 2013-Illustrated

Common Short Text Field Properties 15Microsoft Office 2013-Illustrated

Modifying Number and Currency Fields Number and Currency fields have similar properties because they both contain numeric values.Number and Currency fields have similar properties because they both contain numeric values. Currency fields store values that represent money, and Number fields store values that represent values such as quantities, measurements, and scores.Currency fields store values that represent money, and Number fields store values that represent values such as quantities, measurements, and scores. 16Microsoft Office 2013-Illustrated

Common Number Field Properties 17Microsoft Office 2013-Illustrated

Modifying Date/Time Fields Many properties of the Date/Time field work the same way as they do in fields with a Short Text or Number data type.Many properties of the Date/Time field work the same way as they do in fields with a Short Text or Number data type. One difference, however, is the Format property, which helps you format dates in various ways such as January 25, 2013; 25-Jan-13; or 01/25/2013.One difference, however, is the Format property, which helps you format dates in various ways such as January 25, 2013; 25-Jan-13; or 01/25/ Microsoft Office 2013-Illustrated

Modifying Validation Properties The Validation Rule property determines what entries a field can accept.The Validation Rule property determines what entries a field can accept. You use the Validation Text property to display an explanatory message when a user tries to enter data that breaks the validation rule.You use the Validation Text property to display an explanatory message when a user tries to enter data that breaks the validation rule. 19Microsoft Office 2013-Illustrated

Validation Text Message 20Microsoft Office 2013-Illustrated

Validation Rule Expressions 21Microsoft Office 2013-Illustrated

Creating Attachment Fields An Attachment field allows you to attach an external file to a record.An Attachment field allows you to attach an external file to a record. The Attachment data type is superior to OLE because it stores data more efficiently, stores more file formats, and requires no additional software to view the files from within Access.The Attachment data type is superior to OLE because it stores data more efficiently, stores more file formats, and requires no additional software to view the files from within Access. 22Microsoft Office 2013-Illustrated

Creating Attachment Fields 23Microsoft Office 2013-Illustrated