An entity-relationship (ER) diagram is a picture of the data a system needs to store. It shows the things we care about (entities), the facts we record about them (attributes), and how those things are connected (relationships). Because the diagram is built before any tables exist, it lets you and your stakeholders agree on the structure of the data while changes are still cheap.
In this module the ER diagram is the bridge between a written problem description and an actual database. You will practice reading a scenario, pulling out the nouns that become entities, deciding which details belong as attributes, drawing the relationships, and then labeling each relationship with cardinality (one-to-one, one-to-many, many-to-many) and participation (whether every instance must take part). Notation matters here: Chen-style and crow's foot notation express the same ideas with different symbols, so be sure you can read both and stay consistent within a single diagram.
As you watch the videos below, pay attention to three things. First, how the presenter decides what becomes an entity versus what becomes an attribute. Second, how cardinality symbols are placed and read at each end of a relationship line. Third, how many-to-many relationships are handled, since that choice is where conceptual diagrams begin to turn into something implementable. Try pausing and sketching the examples yourself before the answer appears on screen.
A short introductory walkthrough that builds an ER diagram from scratch, starting with the basic building blocks. Based on its title and description, it covers what entities and attributes are, how they are drawn, and how cardinality is shown between connected entities. It is paced as a beginner's orientation to the notation rather than a deep dive.
Lucid Software makes diagramming tools and produces widely used, well-illustrated ERD explanations, and this part-one video maps directly onto the notation, entity-identification, attribute, and cardinality subtopics in a compact six minutes.
The follow-up video moves past the basics into primary keys, foreign keys, and bridge (junction) tables. Its description indicates it addresses more advanced ERD concepts, including how keys identify entity instances and how a bridge table is used to resolve a many-to-many relationship. At roughly fifteen minutes it has room for worked examples.
Key attributes and the resolution of many-to-many relationships are exactly the points where beginner diagrams most often go wrong, so this video strengthens the relationship-drawing and accuracy subtopics beyond what the introductory part covers.
A hands-on tutorial from Database Star showing how to actually create an ERD in Lucidchart. Expect a demonstration of placing entities, adding attributes or columns, connecting them with relationship lines, and setting the crow's foot symbols within the tool. The channel also offers sample database design guides referenced in the description.
This one closes the gap between understanding notation and producing a diagram yourself, which supports the "translate a problem description into an ER diagram" and "best practices for clear diagrams" subtopics through a practical, tool-based workflow.
Together these videos move from vocabulary to construction. The first establishes entities, attributes, and cardinality notation, supporting MO2 and MO3 by showing how real-world details are classified and how relationship ends are read. The second extends that foundation to keys and bridge tables, reinforcing MO3 and giving you the vocabulary needed to move from a conceptual sketch toward a logical design as described in MO1. The third is a build-along that directly serves MO4 by modeling the full process of producing a correctly notated diagram in a tool. Reviewing your own drafts against the conventions demonstrated in all three is good preparation for the error-checking work called for in MO5.
These videos were chosen from YouTube on October 2, 2026. Each has captions; the player turns them on. Videos on YouTube can be changed or removed — if one no longer plays, tell your instructor. If a player does not appear, use its Watch on YouTube link.