Verification of ER Diagram and Attributes

 

Provide a verification of the reports, forms, and/or processes in terms of the E-R diagram.  The process is designed to verify that all of the data items that appear on a form or report (or that are used in a process) are available in the entities, and that the entities are correctly linked. 

 

When performing the validation, determine the primary entity from which the form or report is derived, and then show how the attributes, including those from other entities, are obtained through foreign keys, composite keys, etc.

 

For each report, form, and/or process provide the following: 


report/form/process:     <report name/form name/process name>
            This involves <x> entities:
                        <entity 1>
                        <entity 2>
                              :
                        <entity n>

           
and <y> composite entities:
                        <composite entity 1>
                        <composite entity 2>
                                :
                        <composite entity n>

The primary entity is <entity primary>

 

The data items are accounted for in the E-R Diagram as follows: 


Trace each data item as follows, depending on the particular case.  The possible cases are

 

Case: data item is an attribute in a non-primary entity, which is not linked directly to <entity primary>

 

Format:
            <data item>: attribute <attribute n> of entity <entity n>

 

Example: Customer No.


Case: data item is an attribute of <entity primary>

Format:
            <data item>: attribute <attribute n> of entity <entity primary >

 

Example: Invoice No.


Case: data item is an attribute that is both the primary key of <entity n> and foreign key of <entity primary>

Format:
            <data item>: attribute <attribute n> of entity <entity primary > and entity <entity n>

 

Example: Order No.


Case: data item is an attribute of <entity n>, which is linked to <entity primary> through <entity composite>

Format:
            <data item>: attribute <attribute n> of entity <entity n>

 

Example: Product No.


Case: data item is an attribute of <entity composite>, which is not linked directly to <entity primary>

Format:
            <data item>: attribute <attribute n> of composite entity <entity composite>

 

Example: Qty Ordered


Case: data item is an attribute of a <entity composite>, which is linked directly to <entity primary>

 

Format:
            <data item>: attribute <attribute n> of composite entity <entity composite> 

 

Example: Qty Shipped
 


Case: data item is derived from other data items

Format:
            <data item>: obtained from the calculation <data item x> <op> <data item y>

 

Example: Total Price


Case: data item is derived from attributes in a non-primary entity

Format:
            <data item>: obtained from the calculation <attribute n> of entity <entity n> <op> <operand2>

 

Example: Unit Price


 Case: data item is obtained from system resources

 

Format:
            <data item>: obtained from system <time/date/etc.>

 

Example: Date

 

Example of Verification of the Customer Invoice (This verification is associated with this E-R Diagram.)

Report: Customer Invoice

The Customer Invoice involves four entities,

The primary entity is INVOICE.

The data items are accounted for in the E-R Diagram as follows: