Engine Atlas

Engine-neutral Database Foundations

Start with the concepts you need to learn databases

Understand tables, rows, keys, and valid writes before moving into SQL results and transactions.

Start Foundation 01

Learning sequence

Six lessons connect the database foundations

Foundation 01 is available now. Foundations 02–06 show the sequence that will follow.

  1. FOUNDATION 01

    Tables, rows, and keys

    Available

    How do a schema and its current rows differ, and which rows do keys protect?

    Compare customers and orders, then predict whether three proposed rows satisfy the primary- and foreign-key rules.

    Start Foundation 01
  2. FOUNDATION 02

    Constraints and relationships

    Which writes do NOT NULL, UNIQUE, CHECK, and relationship cardinality allow?

    Connect constraints and referential actions to entity relationships.

    Planned
  3. FOUNDATION 03

    How a query builds a result

    In what logical order do rows move from FROM to the final result?

    Follow the meaning of JOIN, WHERE, GROUP BY, HAVING, SELECT, ORDER BY, and LIMIT.

    Planned
  4. FOUNDATION 04

    Joins, groups, and subqueries

    Why does the result-row count change when a match is absent or repeated?

    Compare INNER and LEFT joins, aggregates, EXISTS, CTEs, and window results.

    Planned
  5. FOUNDATION 05

    Schema design and normalization

    Which dependencies create update anomalies and call for decomposing a table?

    Connect functional dependencies, 1NF–3NF/BCNF, and denormalization trade-offs.

    Planned
  6. FOUNDATION 06

    Transactions and anomalies

    When can concurrent reads and writes produce an unsafe result?

    Connect COMMIT, ROLLBACK, isolation anomalies, serializability, deadlocks, and retry.

    Planned

MySQL Execution & Concurrency

If you already know basic SQL

If you already understand basic SELECT, JOIN, WHERE, ORDER BY, and LIMIT semantics, you can start with real MySQL execution.

Open MySQL LAB 01