Before you write a single CREATE TABLE statement, someone has to decide what things the database must keep track of, what facts describe each of those things, and how those things relate to one another. That work is logical data modeling. A logical model names the entities in a business domain, lists their attributes, identifies which attribute (or combination) uniquely identifies each instance, and records the relationships and rules that connect entities — all without committing to a particular database product or SQL dialect.
In this module, the logical model is the bridge between understanding a business problem and expressing it in SQL. Entities become tables, attributes become columns, unique identifiers become primary keys, relationships become foreign keys, and business rules become constraints. Normalization — organizing attributes so each fact is stored once, in the place it belongs — is done at the logical level so that the schema you later define is free of avoidable redundancy and update problems.
As you watch the videos below, keep a translation column in your notes. For every modeling term you hear (entity, attribute, cardinality, identifier, many-to-many relationship, bridge table), write the SQL element it will become. Pay particular attention to how one-to-many and many-to-many relationships are represented, since those decisions drive the foreign key and junction-table work you will do in the hands-on portion of this module.
This tutorial introduces entity relationship diagrams from the ground up, walking through what an entity is, how attributes describe it, and how cardinality notation expresses the number of instances that can participate on each side of a relationship. Based on the title and description, it builds a simple ERD step by step rather than assuming prior modeling experience. Expect coverage of the core notation you will see throughout this module.
It maps directly onto the Entities and Attributes and Relationships Between Entities subtopics, and Lucid Software produces this material to support its widely used diagramming tool, so the notation shown is standard and clearly presented.
Part 2 moves past the basics into primary keys, foreign keys, and bridge (junction) tables. The description indicates it addresses how identifiers are chosen and how relationships are actually carried in a design, including the resolution of many-to-many relationships into an intermediate table. At roughly fifteen minutes, it is the most detailed of the three videos.
Primary keys, foreign keys, and bridge tables are exactly the modeling constructs that become key and referential integrity constraints in SQL, making this the clearest link between the logical model and the blueprint-for-SQL subtopic.
This short video compares conceptual and logical data models and explains how they differ in purpose and level of detail. Expect it to clarify where a high-level view of business concepts ends and where attribute-level, identifier-level specification begins. It is aimed at people new to data modeling who tend to blur the two.
It directly addresses the Purpose of Logical Data Models subtopic by situating the logical model within the broader design workflow, which helps you see why the logical phase exists as a distinct step before physical implementation.
Together these videos establish the modeling vocabulary that the rest of the module converts into SQL. The conceptual-versus-logical comparison supports MO5 by showing where the logical phase sits in the design workflow, while the two ERD tutorials supply the entity, attribute, and relationship concepts behind MO2 — understanding the logical model as a blueprint. The treatment of primary keys, foreign keys, and bridge tables prepares you for MO3 and MO4, since those are the structures you will declare with CREATE TABLE and enforce with key and referential constraints. None of the videos teach SQL syntax itself, which reinforces the MO1 distinction between defining structure and querying data: the modeling work shown here is entirely about definition, and the SQL readings and exercises in this module supply the statements that implement it.
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.