The SQL cheat sheet by Charlie Custer, dated April 25, 2022, serves as a quick reference guide for SQL commands, primarily using the PostgreSQL dialect with some CockroachDB-specific commands. It covers a wide range of SQL operations, including creating and managing databases, tables, and schemas, as well as inserting, updating, and querying data. The document also addresses managing SQL constraints, logical operators, and index operations, alongside administration and access management tasks like creating roles and users. Additionally, it highlights performance investigation techniques using EXPLAIN and EXPLAIN ANALYZE commands. Aimed at facilitating easy recall and application of SQL commands, the cheat sheet is slated for availability in a downloadable PDF for convenient desk reference.