Every column in a relational table has a data type, and that type is a promise about what the column may hold. Numeric types (INT, SMALLINT, BIGINT, DECIMAL/NUMERIC, FLOAT), character and string types (CHAR, VARCHAR, TEXT), date and time types (DATE, TIME, TIMESTAMP), and boolean or binary types (BOOLEAN, BLOB/BINARY) each store values differently and allow different operations. Choosing DECIMAL instead of FLOAT for currency, or DATE instead of VARCHAR for a birthdate, is not a stylistic preference — it determines whether the database can validate, sort, compare, and compute on your data correctly.
In this module you write CREATE TABLE statements, and the column definition is where the data type lives: a column name, a type (often with a length or precision, such as VARCHAR(50) or DECIMAL(10,2)), and any column-level constraints such as NOT NULL or DEFAULT. Data types are the first line of defense for data integrity; constraints build on top of them. Keep in mind that exact type names vary by DBMS (MySQL, SQL Server, Oracle, PostgreSQL, SQLite), so expect small differences between videos and your course environment.
As you watch, note three things: which type each presenter chooses for a given kind of value and why, how length or precision is specified, and how the data type sits alongside constraints inside the parentheses of a CREATE TABLE statement. Jot down any type names that differ from the ones your course uses so you can map them later.
A focused tutorial that walks through SQL data types and then connects them to primary keys, foreign keys, and other constraints used when defining a table. Based on its title and description, it covers the main type families you will use in column definitions and shows how constraints are attached to those columns. It is part of a larger SQL full-course playlist, so the examples build on earlier lessons.
This is the most directly on-topic video in the set, pairing data types with the constraint syntax that appears in the same CREATE TABLE statement, which matches the subtopics on choosing types for data integrity and defining columns.
A fast, beginner-oriented overview of core SQL from a business intelligence instructor, using a downloadable SQLite database so you can follow along. It introduces how data is organized into tables with typed columns and demonstrates basic statements against that data. The resource pack lets you practice rather than just watch.
Its hands-on database setup gives you a concrete place to inspect real column definitions and experiment with how values of different types behave, reinforcing the storage-and-integrity rationale behind type choices.
A short introduction to SQL and relational databases from W3Schools, framing what SQL is used for and how tables, rows, and columns relate. It serves as the opening piece of a beginner tutorial series and links back to a written reference page.
W3Schools is a widely used, accurate reference, and this brief orientation supplies the vocabulary of tables and columns you need before studying types in detail; its companion pages also list data types by DBMS.
Together these videos support MO2 most directly: they show column names paired with data types inside table definitions and give you a practice database for building your own. The data-types-and-constraints tutorial also reinforces MO3 by demonstrating PRIMARY KEY, FOREIGN KEY, and NOT NULL style rules attached to typed columns, and the introductory W3Schools video provides the general SQL framing that helps you place DDL among the other SQL sublanguages for MO1. Material on ALTER TABLE (MO4) and the DROP, TRUNCATE, DELETE comparison (MO5) is covered in other resources in this module, so treat these videos as preparation for the column-definition skills those commands later modify.
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.