Find syntax by the job your query needs to do
Use this inventory to scan the scope of the hub.
- Browse syntax by query stage: projection, filtering, grouping, joining, set operations, windows, data changes, constraints, transactions, and plan reasoning.
- Browse by task: choose rows, shape columns, combine tables, aggregate safely, compare periods, preserve null behavior, and debug cardinality.
- Browse by skill family so reference pages connect back to lessons, glossary concepts, and original worked examples.
Browse the SQL reference
Choose a course, reference page, dataset, or project. Practice opens in the app when you are ready.
Shape and filter rows
Start a query, choose columns, filter rows, and control the final output.
Aggregate and group
Summarize rows while keeping grouping grain and group filters explicit.
Join and compose queries
Combine relations, reuse query stages, and compare compatible result sets.
Work with time and windows
Handle periods, ordering, ranking, comparisons, and explicit window frames.
Change and protect data
Make writes observable and preserve transaction and relational guarantees.
Read plans and index signals
Inspect basic plan shape and decide when an index candidate deserves investigation.
Move from reference to a checked query
Use these guides to choose the next topic, then open the workspace for the editor, checks, drafts, reviews, and saved progress.