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A free SQL tutorial in short lessons on one shop database. Every example runs on real PostgreSQL in your browser, and the page checks your answers.
DbSchema Blog
Database design, migrations, SQL and everyday database work — explained with practical examples.
Create Table in PostgreSQL: Syntax, Data Types, Constraints, and Examples | DbSchema
Create tables in PostgreSQL with practical syntax, data types, keys, defaults, and IF NOT EXISTS examples. Design and sync tables with DbSchema.
How to Design a PostgreSQL Schema Visually (Step-by-Step)
PostgreSQL schema design with ER diagrams: create a schema, add tables and columns, set foreign keys, and generate documentation in DbSchema.
PostgreSQL Foreign Key: ALTER TABLE, CASCADE Rules, and Indexing | DbSchema
Learn PostgreSQL foreign key syntax, ALTER TABLE, NOT VALID, CASCADE rules, and indexing. Model and document table relationships in DbSchema.
Describe Table in PostgreSQL: psql, SQL Metadata, and Examples | DbSchema
Describe a PostgreSQL table with psql and SQL metadata queries. See columns, defaults, constraints, indexes, and inspect structure in DbSchema.
SQLite Create Database: CLI, Python, GUI, and DbSchema Setup | DbSchema
Learn how to create a SQLite database with sqlite3, Python, GUI tools, and DbSchema. See file-based setup, first schema steps, and best practices.
SQLite Indexes: CREATE INDEX, EXPLAIN QUERY PLAN, and Tuning Tips | DbSchema
Learn SQLite indexes with CREATE INDEX, composite and partial indexes, EXPLAIN QUERY PLAN, write tradeoffs, and visual tuning in DbSchema.
SQLite Functions Explained with Examples | DbSchema
Learn how SQLite functions work with practical COUNT, SUM, AVG, and string examples in sqlite3 and DbSchema.
SQLite CREATE TRIGGER: BEFORE/AFTER, WHEN Clause, OLD and NEW Examples | DbSchema
Learn SQLite CREATE TRIGGER with BEFORE/AFTER INSERT, UPDATE, DELETE, WHEN clauses, OLD/NEW references, and practical trigger examples.
SQLite LIMIT Clause Explained with Examples | DbSchema
Learn how to use SQLite LIMIT and OFFSET in sqlite3 and DbSchema to control result size, paginate data, and improve query performance.
How to Run MySQL in Docker Step by Step | DbSchema
Run MySQL in Docker with one docker run command, persist data in a named volume, connect from the host and from DbSchema, and fix common startup errors.