Avoiding SQL Pitfalls | Dataford Interview Questions

Explain the difference between a SQL commit and a SQL branch, and what LEFT JOIN and RIGHT JOIN do.

Provide a concise explanation using PostgreSQL terminology and SQL examples. Clarify that COMMIT is a transaction command and that branch is not standard SQL, then demonstrate both join directions with the supplied tables.

Output

Return join_type, branch_id, branch_name, commit_id, and commit_message.
Include results from both join directions, preserving unmatched rows.
Order by join_type, then branch_id, then commit_id, with NULL values last.

Schema

branches

Column	Type	Description
branch_idPK	INT	Identifier for a branch record
branch_name	VARCHAR(80)	Human-readable branch name

commits

Column	Type	Description
commit_idPK	INT	Identifier for a commit record
branch_id	INT	Branch associated with the commit
commit_message	VARCHAR(160)	Short description of the commit

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