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1 Page 1 of 15 Chapter 9 Chapter 9: Deveoping the Logica Data Mode The information requirements and business rues provide the information to produce the entities, attributes, and reationships in ogica mode. Entities represent the "things" about which the enterprise is interested in keeping information. The attributes for each entity and the reationships between the entities are determined by business rues. This chapter expores the foowing topics: Buiding the data mode in ERwin Creating entities Adding attributes Using the Key Group Editor Using the Domain Editor First we create a new data mode diagram and set the modeing environment. Then we use ERwin s ogica mode toos to create the entities and attributes. ERwin s ogica mode object editors are used to set properties for the diagram, as we as entities and attributes. Lasty, we examine the editors for defining the key groups and the domain dictionary. Buiding the Data Mode in ERwin Remember that an ERwin data mode has two modes, ogica and physica. That means a singe ERwin diagram incudes both a ogica and a physica mode. It is important to note that, in ERwin, the ogica mode and physica mode are tighty inked. Making a change in the ogica mode automaticay incudes the same change in the physica mode, uness the object is defined as ogica ony. By the same token, changes to the physica mode are refected in the ogica mode. Changing the ogica name of a ogica mode object wi change the corresponding physica mode object, unti you edit the coumn or tabe name directy. Changing the name of a physica mode object does not change the name of the corresponding ogica mode object. In the sections that foow, I expore Creating a new ERwin diagram Setting the modeing environment Using the Diagram Editor Editing on the diagram Creating a New ERwin Diagram fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

2 Page 2 of 15 Buid the ogica mode for Betty s Ice Cream Shop by performing the foowing steps: 1. Seect the New icon on the toobar or seect Fie, New. 2. Seect the SAMPLE tempate from the ERwin Tempate Seection diaog. Figure 9.1 shows the diaog. Figure 9.1 The SAMPLE tempate contains a set of predefined options. You can create your own tempate by using the Fie, Save As option. Customize one of the tempates deivered with ERwin, or use the Bank Diagram option. Setting the Modeing Environment Next, you set the modeing environment options for the creation of the Betty s Ice Cream Shop ogica mode. For the exampe, this entais setting the ERwin window dispay options and seecting the methodoogy preferences. Seecting the Window Dispay Options To seect the ERwin window dispay options, seect the Window menu and check the foowing options: Stored Dispay Tabs The sampe tempate contains a set of exampe stored dispays. You cannot see these tabs unti this seection is made. Toobar The toobar has icons for commony used functions, a rea time-saver. Status Bar The status of an operation can be vauabe information. Independent Attribute Browser Using domains is a best practice. Domains hep with consistency and foowing standards. ERwin Toobox Dispaying the toobox on the ERwin desktop is a must. The Window menu coses each time you make a seection. This behavior is annoying, but keep opening and seecting each option. Note that the ModeMart menu item and the ModeMart toobar are not avaiabe if you are not using ModeMart. The seections shown in Figure 9.2 are my own preferences. Figure 9.2 The ERwin dispay window aows you to contro the ook and fee of the diagram workspace. You can eect whether to hide or dispay the toobars and tooboxes, as we as dispay tabs and the status bar. Seecting Methodoogy You wi use the IE notation for both the ogica and physica modes. To open the Preferences diaog, shown in Figure 9.3, seect Option, Preferences, and on the Methodoogy tab, choose IE notation for both modes. Leave the other options at the defaut seections. Figure 9.3 On the Methodoogy tab, seect the notation ERwin wi use for the ogica and physica mode. IE methodoogy notation uses "crow's feet" to visuay depict the "many" side of a reationship. Using the Diagram Editor To use the Diagram Editor, seect Edit, Diagram. The Diagram Editor has three tabs for entering information fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

3 Page 3 of 15 about the diagram (see Figure 9.4): Genera Definition UDP Figure 9.4 Note that ERwin provides support for different versions of some target servers, such as DB2. If ERwin supports more than a singe version of the target server, the Version drop down ist appears. The Genera tab is where you enter a name for the diagram and the author, as we as seect the database information. I consider it a best practice to name the diagram and provide the author s name as we: Name and Author Enter a name for the diagram and the author of the mode. In my mode, the diagram is caed Betty's Ice Cream Shop, and I entered my name as the author. Database Info It is not necessary to seect the Target Server and Version at this time. However, you can seect it now if you ike. For Betty's Ice Cream Shop, Access 97 is seected as the database patform for a very common reason: It is the program Betty Wison uses. Avaiabiity is often the basis for patform decisions. It is important to enter a definition for the diagram on the Definition tab. Remember to use business anguage. Figure 9.5 shows some ideas for a starter set of information that you can incude in the diagram: Name of the project: Betty's Ice Cream Shop. Date the diagram was created: 11/08/1999. Steward of the mode: M. Cara DeAngeis. A brief restatement of the probem definition or business need for Betty's Ice Cream Shop. A reference to the pattern for package configuration and campaign management, which fits the probem domain. Patterns represent we-known modeing concepts used esewhere within the enterprise. Figure 9.5 Use the Diagram Editor, Definition tab to incude important information about the diagram itsef. I ike to incude the name of the modeer responsibe for creating and maintaining the diagram. Every diagram object in ERwin has the option of attaching user-defined properties (UDPs). Creating UDPs and using the UDP Editor is addressed in Chapter 14, "Advanced Features for the Logica Mode." For this exampe, I created a UDP named Modeer with the vaue MCD, my initias, as shown in Figure 9.6. Figure 9.6 The Diagram Editor, UDP tab aows you to set properties for user-defined properties that have been attached to the diagram object. Editing on the Diagram ERwin has a nice feature that aows you to enter the entity name and attributes without opening an editor. To use fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

4 Page 4 of 15 on-diagram editing, enter the entity name and press the Enter key. Figure 9.7 shows the on-diagram edit to add an attribute. You can cyce through the attributes by pressing the Enter key to advance the edit mode to the next attribute. Figure 9.7 ERwin s on-diagram editing feature aows you to enter the entity name and attribute names without opening their corresponding editors. However, you wi need to use the appropriate editor to set other important properties. Creating Entities Entities provide the foundation for a ogica mode. ERwin aows you to enter entity properties such as name, definition, and notes and attach UDPs. Reca that a ogica mode can contain independent and dependent entities. An independent entity is an entity whose instances can be uniquey identified without attribute vaues from its reationship to another entity. A dependent entity is an entity whose instances cannot be uniquey identified without determining its reationship to another entity or entities. Dependent entities are aways chid entities where a or part of the primary key contains the primary key of the parent entity. These migrated foreign key attributes are necessary to define a specific instance. ERwin represents an entity using a rectanguar box with a horizonta ine that divides the upper haf of the box from the ower haf. The primary key attributes reside in the upper haf of the entity box, and non-key attributes appear in the ower haf. When you add a new entity to the diagram, ERwin provides a defaut name, E/n, where the etter E represents entity and n is a unique number. Figure 9.8 shows a new entity and its E/n defaut name, E/6. In the sections that foow, I expore Using the entity too Using the Entity Editor Adding the name and definition Using the Entity Too To use the entity too in the ERwin toobox, cick the entity too and then cick the diagram. The mouse pointer changes to provide a visua cue that the entity too is in use, as shown in Figure 9.8. Figure 9.8 The Entity too in ERwin s toobox aows you to quicky add new entities to the diagram. Notice the mouse pointer changes to indicate that the entity too is seected. As ong as the entity too is seected, a new entity is added each time you cick on the desktop. If you add a new entity unintentionay, you can deete it by cicking the pointer too, cicking the entity to seect it, and pressing the Deete key. Note that ERwin ony provides the option to deete from the mode. The Deete from Subject Area option is not avaiabe for entities with defaut names. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

5 Page 5 of 15 Enter an appropriate ogica name for the entity. Remember to use good naming conventions. Using the Entity Editor To use the Entity Editor to add or change an entity s properties, seect Edit, Diagram or right-cick the entity and seect Entity Editor. Figure 9.9 shows the right-cick shortcut menu. Figure 9.9 Right-cick an entity to open the Shortcut menu to the editors. Doube-cick an entity to open the editor that is currenty seected. Use the Entity Editor to enter or change an entity s name and definition. The Entity Editor aso aows you to attach three notes to an entity as we as associate an icon with an entity. The Entity Editor contains the foowing contros: Entity Here, you see the name of the seected entity. To edit the properties of another entity, seect the entity from the drop-down ist box. Name Cick to change the name of an entity. Logica Ony Seect this check box to make the entity part of the ogica mode ony. Do not seect this check box if the entity is to appear in both the ogica and physica modes. Entities specified as ogica ony are not represented by a tabe in the physica mode. To change the name of an entity, cick in the Name edit box and enter the new name. An entity name often appears in a uppercase etters. Seect good names that use business anguage and that are representative of the instances. The Definition tab contains a set of standard editing too icons, Cut, Copy, Paste to Cipboard, and Print Preview. The Entity Editor aso incudes a set of tabs that aow you to enter the foowing: Definition Notes UDPs Icon The Definition tab is shown in Figure The definition in the exampe is written from the perspective of the business partner or cient, Betty's Ice Cream Shop. You shoud word entity definitions using business terms. Figure 9.10 Use the Entity Editor to change the entity name and add or change the definition. To edit a different entity, seect it from the drop-down ist. ERwin's drop-down ists aow you to quicky ocate a specific ist item by typing the first few characters. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

6 Page 6 of 15 The Entity Editor aso aows you to attach up to three notes to an entity. These notes are free-form text that can store specia information regarding an entity. For exampe, you can use a note to attach sampe data or identify the source system or system of record for the instances of an entity. Reca that a user-defined property is any usefu or important information about an ERwin object, in this case, an entity. An entity in the ogica mode and the tabe in the physica mode cannot share a UDP. Using the UDP Editor is covered in Chapter 14. The Icon tab aows you to attach sma and arge icons to an entity, as shown in Figure You can import bitmaps for use as icons using the Icon Editor. To open the Icon Editor, cick the Editor icon. To import a bitmap, cick the Import button and browse for the bitmap. Figure 9.11 Use the Icon tab to associate icons with entities. Use the dispay options to dispay the icons. You must seect the entity icon in the stored dispay for ERwin to dispay the sma icon. To dispay arge icons, right-cick the diagram and seect Dispay Leve, Icon. Adding Attributes Attributes represent the information that the enterprise is interested in coecting and maintaining about an entity. Reca that attributes come in two primary types, key attributes and non-key attributes. In ERwin, key attributes reside above the entity ine and non-key attributes are beow the ine. You can add attributes to an entity using on-diagram editing or using the Attribute Editor. Using On-Diagram Editing To add attributes using ERwin s on-diagram editing feature, cick the entity once to seect it, and once again to use on-diagram editing. Press the Enter key to cyce through the attributes to pace the new attribute in the appropriate spot. Figure 9.12 shows the addition of a new attribute using the on-diagram edit feature. Notice that ERwin assigns a defaut name of the form attribute_name when you add new attributes using on-diagram editing. Figure 9.12 You can quicky add attributes to an entity using on-diagram editing. To use on-diagram editing, cick the entity once, and then cick again. If you perform the second cick too quicky, ERwin wi interpret it as a doube cick, and open the seected editor. Using the Attribute Editor To use the Attribute Editor, seect Edit, Attribute or right-cick an entity and seect Attribute Editor. The Attribute Editor aows you to add and change attribute properties for a entities in the diagram, as we as specify vaues for UDPs, as shown in Figure Figure 9.13 Use the Attribute Editor to set additiona properties for attributes. The functionaity of the Attribute Editor incudes Entity name The drop-down contro aows you to switch to another entity. You cannot change the entity fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

7 Page 7 of 15 name from the Attribute Editor. Cick the button to the right of the entity name drop-down ist to aunch the Entity Editor. Attribute ist Doube-cick an attribute to open the Domain Editor. (You' read more about the Domain Editor in Chapter 14.) When more than a singe attribute is present, the up/down icons are active. Cick an attribute and cick the up or down icon to move the attribute up or down in the ist. New To open the New Attribute diaog and add an attribute, cick this button. Figure 9.14 shows the New Attribute diaog. Figure 9.14 Use the New Attribute diaog to add a new attribute within the Attribute Editor. ERwin automaticay uses the attribute name as the coumn name. Whie adding a new attribute using the New Attribute diaog shown in Figure 9.14, you can seect the ogica domain, enter the attribute name and coumn name, and define the attribute as ogica ony by doing the foowing: Sort You can seect to view the ogica domains in aphabetica or hierarchica order. I recommend viewing the domains in hierarchica order because it ets you see the parent domain for any user-defined domains. Domain ist Cick a domain to seect as the domain for the new attribute. Attribute Name Enter the attribute name. Remember to use naming conventions and seect a ogica name that is indicative of the domain of vaues. Coumn Name The coumn name defauts to the ogica name with any spaces repaced by underscores, and ERwin truncates the name to meet physica database requirements. Logica Ony To indicate that the attribute shoud be present in the ogica mode ony, seect this option. Rename To open the Rename Attribute diaog (shown in Figure 9.15) and rename an attribute, cick this button. An attribute seected as ogica ony wi not exist in the physica mode and wi not be created in the database. Figure 9.15 Use the Rename Attribute diaog to change the name of an attribute. Simpy enter the new name and cick the OK button. Deete To deete the seected attribute, cick the Deete button. Take care; there is no undo faciity to give you a chance to take it back. The ony option is to cance a the changes and cose the diaog. Reset To reset the properties of the seected attribute, cick this button to dispay the Reset Attribute Property diaog. This diaog aows you to return overridden properties to the defaut domain settings. Figure 9.16 shows the Reset Attribute Property diaog options. Figure 9.16 Use the Reset Attribute diaog to reset the properties of a singe attribute, a the attributes in an entity, or a attributes in a mode. You can aso seect which properties to reset. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

8 Page 8 of 15 Migrate To seect the primary key attribute properties that wi migrate to foreign keys, cick this button to dispay the Migrate Attribute Property diaog, shown in Figure Figure 9.17 Use the Migrate Attribute Property diaog to seect the primary key properties that wi migrate as foreign key properties. Tabs To set the ogica domain, enter a definition, add a note, assign UDP vaues, and define the key group attributes, seect the appropriate tab. Reset ERwin aows you to attach a domain to a coumn as we as override the domain properties and assign new properties. Cicking the Reset button dispays the Reset Attribute Property diaog, with which you can return overridden properties to the defaut domain settings. The Reset Attribute Property diaog contains two primary sets of information. The upper set of options enabes you to contro the number of attributes whose properties wi be reset: Ony attribute Seect to ony reset the properties of the seected coumn. The name of the seected coumn appears in the text abe. A attributes of entity Seect to reset the properties of a attributes in the seected entity. The name of the seected entity appears in the text abe. Reset a attributes in mode Seect to reset the properties of a attributes in the entire mode. Making this seection enabes the option to ony reset user-defined domains. The ower set ists the attribute properties that can be reset: Name Seect this check box to reset the seected attribute name to the ogica domain name seected for the attribute. Logica Ony Seect this option if you want to reset the Logica Mode Ony property to the vaue set for the ogica domain. Required I assume that this option was intended to aow you to reset the Required property to the defaut (ceared). I tested this option, and seecting it appeared to have no effect on the mode. I do not use this feature, and I coud find no information in the onine documentation about its purpose. Definition Seect this option if you want to reset the definition for the seected coumns to the definition for the ogica domain. The ogica datatypes that come with ERwin do not incude definitions, so the effect might be to cear the definition. Note Seect this option if you want to reset the Note property for the seected attribute to the inherited note vaue for the domain. UDP Seect this option if you want to reset the vaue of the user-defined properties for the seected attribute to the defaut UDP vaue. Icon Seect this option if you want to reset the icon assigned to the attribute to the one associated with the ogica domain assigned to the attribute. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

9 Page 9 of 15 Use caution when using the Reset Attribute Property diaog. Resetting properties such as Name and Definition can resut in the oss of vauabe business information. Migrate ERwin automaticay migrates a primary key attributes as foreign key attributes in a chid entity. The Migrate Attribute Property diaog aows you to seect the attribute properties that migrate with the foreign key for the reationships in the mode. The seections you make appy to a migrated foreign keys in the mode, not just the entity seected. Migrate a the properties of primary keys to foreign keys uness there is a sound business need to do otherwise. If you change the name of a foreign key using the Attribute Editor, ERwin automaticay adds the name as a roe name in the reationship. These names persist even if the name of the primary key changes in the parent entity. Cick the Migrate button in the Attribute Editor to open the Migrate Attribute Property diaog, shown in Figure The foowing options are avaiabe: Domain Seect this option to migrate primary key attached domains to foreign key attributes. Name Seect this option if you want to migrate the primary key attribute name to a foreign attribute. Logica Ony Seect this option if you want to migrate the primary key attribute Logica Ony property to a foreign key attribute. Definition Seect this option if you want to migrate the primary attribute definition to a foreign key attribute. Note Seect this option if you want to migrate the primary key attribute note to a foreign key attribute. UDP Seect this option if you want to migrate the primary key attribute UDP to a foreign key attribute. Icon Seect this option if you want to migrate the primary key attribute icon to a foreign key attribute. Be carefu making changes to the options for migrating properties. ERwin automaticay cascades a the appropriate attribute property information to foreign keys in chid entities throughout the diagram and overrides a the properties except name. The domain of a foreign key can be changed and wi remain changed as ong as you make no changes to the primary key of the parent entity. However, the foreign key domain reverts to the domain of the primary key if the domain of the primary key is changed. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

10 Page 10 of 15 Attribute Editor Tabs The Attribute Editor contains the foowing tabs that aow you to set attribute properties: Genera Definition Note UDP Key Group The Genera tab, shown in Figure 9.18, aows you to set the foowing properties: Sort Choose to view the ogica domains in aphabetica or hierarchica order. I recommend viewing the domains in hierarchica order because it aows you to see the parent domain for any user-defined domains. Domain ist To seect a domain for the attribute, cick it. Launch the Domain Dictionary Editor by cicking the button marked with the eipsis to the right of the domain view options. You' find more information about this in the "Using the Domain Dictionary Editor" section ater in this chapter. Icon To associate an icon with the attribute, seect an icon from the drop-down ist. Launch the Icon Editor, shown in Figure 9.19, by cicking the button marked with the eipsis to the right of the Icon dropdown ist box. Primary Key To indicate that the attribute is part of the primary key, seect this option. Logica Ony To indicate that the attribute shoud be present in the ogica mode ony, seect this option. Required To indicate that an attribute cannot have a nu vaue, seect the Required option. Figure 9.18 Use the Attribute Editor, Genera tab to set some important attribute properties. You can aso aunch the Domain Dictionary Editor and Icon Editor using the buttons to the right of each drop down. Icon Editor ERwin aows you to associate an icon with an attribute. You can aso import new icons as we as rename and deete a icons except the defaut icons deivered with ERwin. To aunch the Icon Editor, shown in Figure 9.19, cick the button marked with an eipsis to the right of the Icon drop-down ist box. Figure 9.19 Use the Icon Editor to import new icons to be incuded in ERwin's ist of avaiabe icons. The functionaity of the Icon Editor aows you to Import To import an icon, cick this button to open the ERwin Open Fie diaog and seect a bitmap to add to the ist of icons in the Icon Editor. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

11 Page 11 of 15 Rename To rename an icon, cick this button to open the Rename Bitmap diaog and enter a new name for the seected icon. Note that the icon bitmap is renamed ony in the Icon Editor; the name of the origina bitmap is not changed. Deete To remove the seected icon from the ist in the Icon Editor, cick this button. Note that the origina bitmap is not deeted and that you cannot deete the defaut icons deivered with ERwin. The Definition tab, shown in Figure 9.20, aows you to enter an attribute definition. It contains standard editing functions: Cut, Copy, Paste to Cipboard, and Print Preview. Print Preview aso has standard preview functions: Save (as a.txt fie), Print, Find, and Repace, as we as the previousy mentioned standard edit functions. The Key Group tab of the Attribute Editor aows you to seect which attributes are incuded in the key groups for each entity. Primary key groups are based on whether the attribute is a key or non-key. Foreign key groups are based on entity reationships. Figure 9.20 Use the Definition tab to add or change an attribute definition. Note that the Topping Identifier attribute is defined as an artificia unique identifier, a number with no meaning. The Key Group tab contains the foowing: Key Group Membership This ists the key groups defined for the seected entity. An X in the box next to the key group name indicates that the seected attribute is a member. Add an attribute to a key group by seecting the check box next to the key group name. Remove an attribute from a key group by cearing the check box next to a key group name. Key Group Editor To aunch the Key Group Editor, cick the button marked with an eipsis. Show FK Groups Seect this option to dispay foreign key groups in the key group membership ist. Cear the option to hide foreign key groups. Using the Key Group Editor The Key Group Editor, shown in Figure 9.21, aows you to seect the member attributes for a key group. You cannot change foreign key group members in the Key Group Editor, but you can add and remove attributes from the primary, aternate, or inversion entry key groups. The options are Entity This indicates the name of the seected entity that contains the key groups. To view the key groups in a different entity, seect the entity name from the drop-down ist. To open the Entity Editor, cick the button marked with an eipsis to the right of the entity name drop-down ist. Key Group This dispays the names of a key groups defined for the seected entity. Show FK Groups Seect this option to dispay foreign key groups in the key group membership ist. Cear the option to hide foreign key groups. New To add a new key group, cick this button to aunch the New Key Group diaog, which is discussed in the next section. Rename To rename a key group, cick this button to open the Rename Key Group diaog. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

12 Page 12 of 15 Deete To deete the seected key group, cick this button. This option is not avaiabe for a primary key group or foreign key group. Figure 9.21 Use the Key Group Editor to seect the members for a key group. You can edit the key groups for a different entity by seecting it from the drop-down ist. You can ony change foreign key attributes by changing the primary key attributes of the parent entity from which the foreign key group migrates. New Key Group The New Key Group diaog, shown in Figure 9.22, aows you to enter or change the name of the key group or index: Key Group Enter or change the ogica name for the key group. Index Enter or change the physica name for the key group. The diaog aso aows you to specify the key group type: Aternate key (unique) An aternate key is an attribute that uniquey identifies an instance of an entity but was not seected as the primary key. ERwin generates a unique index for each aternate key. Inversion entry (non-unique) An inversion entry is an attribute that is used to access instances of entities but that cannot be used to uniquey identify a specific instance. ERwin generates a non-unique index for each inversion entry. Figure 9.22 Use the New Key Group Editor to add an aternate or inversion entry key group. Adding Members to Key Groups The Members tab of the Key Group Editor, shown in Figure 9.21, aows you to seect the member attributes of most key groups defined for the current entity: Avaiabe Attributes Lists the attributes in the entity that do not currenty participate in the key group. Key Group Members Lists the attributes in the entity that currenty participate in the key group. To add a new attribute, cick an attribute in the Avaiabe Attributes ist; then cick the arrow pointing toward the Key Group Members ist. To remove an attribute, cick an attribute in the Key Group Members ist; then cick the arrow pointing toward the Avaiabe Attributes ist. The Key Group Editor's Genera tab, shown in Figure 9.23, aows you to specify key groups as aternate keys inversion entries. You cannot change the key group type for primary keys and foreign keys in this editor. Key groups are: fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

13 Page 13 of 15 Primary Key Seected if the key group is the primary key for the entity. Aternate Key (unique) Seected if the key group is an aternate key for the entity. Cicking this button changes an inversion entry key group to an aternate key group. Inversion Entry (non-unique) Seected if the key group is an inversion entry key group for the entity. Cicking this button changes an aternate key group to an inversion entry key group. Foreign Key Seected if the key group is a foreign key for the entity. Logica Ony Ony avaiabe for an aternate key or inversion entry. Seect to make the seected key group part of the ogica mode ony. Cear this check box to incude the seected aternate key or inversion entry in the physica mode as a unique or non-unique index. Figure 9.23 Use the Genera tab to change the key type for aternate and inversion entry key groups. The Definition tab of the Key Group Editor aows you to enter a key group definition. It contains standard editing functions: Cut, Copy, Paste to Cipboard, and Print Preview. Print Preview aso has standard preview functions: Save (as a.txt fie), Print, Find, and Repace, as we as the standard edit functions. Simiar to the Definition tab, the Note tab of the Key Group Editor aows you to enter a note that is assigned to the key group. The Note tab aso contains the standard editing functions. The UDP tab in the Key Group Editor aows you to assign UDP vaues to the key group. Using the Domain Dictionary Editor ERwin domains are a fexibe too for defining a set of properties and assigning them to an attribute or coumn. Using the Domain Dictionary Editor, you can define new domains with ogica and physica properties, which can be reused as independent attributes and independent coumns. You can aso modify the properties of any userdefined domain, as we as a the properties of the five standard domains shipped with ERwin, except the domain name and domain parent. You can aso use the Domain Dictionary Editor to create new domains. The Domain Dictionary Editor, shown in Figure 9.24, aows you to view and edit the ogica properties of a domain. There are two sets of properties: one for the domain itsef (non-inheritabe properties) and another for the attributes assigned the domain (inheritabe properties). Figure 9.24 Use the Domain Dictionary Editor to create and set the properties for user-defined domains. New Domain The New Domain diaog in the Domain Dictionary Editor aows you to enter the name for the domain in the ogica and physica mode. To open the New Domain diaog, cick the New button in the Domain Dictionary Editor. Figure 9.25 shows the creation of a new domain caed Expiration Date. Figure 9.26 shows the new domain added to the domain ist. Note the properties on the Genera tab for the new domain. Figure 9.25 Use the New Domain diaog to create user-defined domains based on the datatype domains deivered with ERwin. Figure 9.26 The New Domain, Expiration Date, uses the Datetime domain to create a specific type of date. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

14 Page 14 of 15 The Genera tab in the Domain Dictionary Editor aows you to set the foowing properties: Domain Parent This indicates the parent of the seected domain. To change the parent, seect a different domain from the ist. This property cannot be inherited. Domain Icon This shows the icon for the seected domain. To change the icon, seect a different icon from the ist. This property cannot be inherited. Each of the defaut domains shipped with ERwin is assigned an icon: <unknown>, Bob, Datetime, Number, and String. Cick the eipsis button next to the Domain Icon drop-down box to open the Icon Editor from which you can import bitmap fies to use in your ERwin diagram. See the "Icon Editor" section earier in this chapter for more information. Name Inherited by Attribute Type the name or ERwin macro that the attribute inherits when associated with the seected domain. The ERwin macro %AttDomain automaticay migrates the ogica domain name to the attribute name. Icon Inherited by Attribute This is the icon that the attribute inherits when associated with the seected domain. To change the icon, seect a different icon from the ist. Cick to open the Icon Editor from which you can import bitmap fies to use in your ERwin diagram. See the "Icon Editor" section earier in this chapter for more information. Logica Ony Seect this check box if you want the seected domain to appear in the ogica mode ony. Cear this check box if you want the seected domain to be avaiabe in both the ogica and physica mode. Required Seect this check box if you want attributes associated with this domain to be a required fied in a data entry appication. This option corresponds to the NOT NULL option in a physica mode. The Definition tab for the Domain Editor, shown in Figure 9.27, aows you to enter two definitions for each domain: one for the domain itsef and another that wi be inherited by attributes using that domain: Domain Definition Type or edit the definition for the seected domain. This definition is non-inheritabe. Definition Inherited by Attribute Enter the definition that wi be inherited by the attributes with the domain. Simiar to the Definition tab, the Note tab for the Domain Dictionary Editor aows you to enter two notes for each domain, one for the domain itsef and another that wi be inherited by attributes using that domain. The UDP tab in the Domain Dictionary Editor aows you to assign two sets of UDP vaues, one for domain itsef and one for the attributes using that domain. Figure 9.27 Use the Domain Dictionary Editor, Definition tab to add a definition for a user-defined domain. Note the definition of the Expiration Date domain. Summary Begin deveoping the ogica data mode by creating a new ERwin diagram. To create a new diagram, seect an ERwin tempate. You can save any mode as a tempate to use as the basis for new diagrams. After seecting the tempate, set the modeing environment by seecting the ERwin workpace dispay options and the methodoogy notation. The workpace dispay options aow you to contro the toobars and tooboxes that wi be dispayed in the diagram. Methodoogy notation aows you to seect the visua notation options for the ogica and physica mode. Use ERwin's Diagram Editor to incude important information about the diagram itsef. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01

15 Page 15 of 15 Using ERwin s on-diagram editing features, you can quicky add the entity and attribute names. To open ondiagram editing, cick the entity and cick again. Press the Enter key to move from the entity name to attribute name. Add entities by seecting the entity too from the ERwin toobox and cicking on the diagram to add an entity. As ong as the entity too is seected, a new entity wi be added each time you cick on the diagram. Use the Entity Editor to set and edit the properties for entities. Attributes can be added using ERwin s on-diagram editing feature or the Attribute Editor. Use the Attribute Editor to set and edit properties for attributes. You can reset one or more attribute properties to the defaut using the Reset diaog. The Reset diaog aows you to reset the properties of a singe attribute, every attribute in an entity, or every attribute in the mode. Use Erwin s Migrate diaog to seect the primary key attribute properties that migrate to foreign key attributes. ERwin s Key Group Editor aows you to add aternate and inversion entry keys. Aternate keys are one or more attributes that uniquey identify a specific instance of an entity, but were not seected as the primary key. Inversion entry keys are one or more attributes that faciitate the way users wi access the data. ERwin domains are a fexibe too for defining a set of properties and assigning them to an attribute or coumn. Using the Domain Dictionary Editor, you can define new domains with ogica and physica properties, which can be reused as independent attributes and independent coumns. You can aso modify the properties of any userdefined domain, as we as a the properties of the five standard domains shipped with ERwin, except the domain name and domain parent. Now that you know how to create entities and attributes, you re ready to create the reationships between them. In the next chapter I expain how to create reationships between entities using ERwin s reationship toos. Copyright Macmian USA. A rights reserved. fie://j:\macmiancomputerpubishing\chapters\in073.htm 3/22/01