A finished IT 220 Unit 2 entity relationship diagram: identifiers marked, cardinality written as the constraint an engine will enforce, and expected volume noted on every entity. Searches like "it 220 unit 2 assignment example", "it220 unit 2 sample" and "it 220 unit 2 example" land here.
What a finished IT 220 Unit 2 entity relationship diagram looks like
What arrives is a diagram with build notes rather than a diagram alone. Entities appear as boxes holding their attributes, with the chosen identifier marked and any attribute that will hold a long value or a file flagged, because those decide what a table costs on disk. Relationship lines carry cardinality and optionality, and a note beside each says which side will hold the reference once the model becomes tables. Every entity is annotated with a rough expected row count and how quickly it grows, so a reader can tell the small lookup list from the one that will dominate storage. Many-to-many links are marked for resolution with the linking entity named. A legend fixes the notation, and a scope note says what the model deliberately leaves out.
How a IT 220 Unit 2 example is structured
Identifiers are settled before anything else is drawn because the key decision propagates: it becomes the primary key, it is what every reference copies, and it fixes the index the engine reads first. Where a reference will physically live is written on the diagram rather than left for the build, since the side a relationship is stored on has consequences for how rows are inserted and for what a deletion has to reach. Volume annotations sit on the entities because a model is judged partly on whether its designer knows which table will hold a thousand rows and which will hold millions. Resolution of many-to-many links is named here rather than performed, keeping the conceptual picture readable while recording work the schema unit will have to do. The scope note closes it, since a drawing cannot be called incomplete until somebody says where its edge is.
Identifiers fixed before any line
The key chosen for each entity is settled first, because every relationship drawn afterward copies it and every lookup the engine performs begins there.
Which side stores the reference
Each relationship records where its reference will physically live, since that choice governs how rows are inserted and what a deletion has to reach.
Expected volume noted on each entity
A rough row count and a growth rate sit beside every box, separating the small lookup table from the one that will fill a disk.
Large attributes flagged where they sit
Columns expected to hold long text or binary content are marked, because they change what a single row costs to store and to read.
Notation legend and a scope note
One declared convention and a plain statement of what the model excludes let a marker judge the drawing against its own stated edge.
Where marks go in IT 220 Unit 2
Diagrams lose points when they are decorative. Boxes and lines with no identifiers marked cannot be turned into tables, and this unit exists to produce something buildable. Cardinality guessed from the shape of a sentence rather than from the requirement gives an engine the wrong rule to enforce, which surfaces as rejected inserts later in the term. Relationships with no side recorded for the reference push a decision into the build where it gets made carelessly. Drawings with no sense of scale treat a lookup list of six states and a transaction table as equally weighted. Two notations mixed on one page make every reading arguable. Attributes floating free of any entity have nowhere to be created. A model traced from an employer's production schema is that employer's design work.
Get a IT 220 Unit 2 example written to your instructions
Upload the Unit 2 brief and the rubric your IT 220 classroom posts, plus the scenario and any diagramming tool the section requires. The custom example fixes identifiers first, records where each reference lives and how large each entity grows, flags the long attributes, names the linking entities, and closes on a declared notation with a scope statement. First one free, 24-48h.
IT 220 Unit 2 questions, answered
Does the diagram have to be buildable at this stage?
It has to be headed that way. A conceptual model is allowed to leave a many-to-many link unresolved and to describe an attribute loosely, but anything that could never become a table, an entity with no identifier or a relationship nobody can store, is a defect rather than a level of abstraction. Mark the unresolved items so a marker sees deliberate deferral.
Where do the row counts come from?
From the scenario and from stated assumption. Nobody expects a measured figure in a design unit, so an order of magnitude with a sentence explaining it is what the annotation is for: a few dozen departments, several thousand customers, a transaction table growing with every order. Write the reasoning beside the number and it becomes evidence instead of decoration.
Can I diagram the system I administer at work?
Not for a graded file. A production schema is a design your employer paid for, and it usually reveals what the business records about its own customers as a side effect. Build the scenario the assignment gives you. Experience with a real installation tends to show up anyway, in the volume annotations and in noticing which relationship will hurt.