Join a parent to pre-aggregated totals.
SQLite: Aggregate the child rows first to produce at most one joined row per parent.
CREATE TABLE people (id INTEGER PRIMARY KEY, name VARCHAR(30));
CREATE TABLE orders (id INTEGER PRIMARY KEY, person_id INTEGER, amount INTEGER);
INSERT INTO people VALUES (1,'Ada'),(2,'Grace'),(3,'Lin');
INSERT INTO orders VALUES (1,1,10),(2,1,20),(3,2,5);
SELECT p.name, COALESCE(t.total,0) FROM people p LEFT JOIN (SELECT person_id,SUM(amount) AS total FROM orders GROUP BY person_id) t ON t.person_id=p.id ORDER BY p.id;Expected output EXAMPLE
Ada|30 Grace|5 Lin|0
Details
Requires SQLite 3.40 or later. Run with sqlite3 demo.db in a scratch directory. Result rows below use | between columns, without headers; client display formatting may differ. Aggregate the child rows first to produce at most one joined row per parent. The CREATE and INSERT statements provide all input data. Run the complete example in a fresh scratch database or schema.
Tested on Ubuntu 24.04.5 LTS · · SQLite 3.45.1 · bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3
Test inputs, results and environment
The exact published code ran in a dedicated Linux test container with prepared inputs. Snippet process uid 65534 with a read-only root filesystem and temporary working files. Networking disabled. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.
- Architecture / host kernel
- x86_64 / 6.18.54.1-microsoft-standard-WSL2
- Snippet identity / locale
- uid=65534, gid=65534 (unprivileged process) / C.UTF-8
- Interpreter invocation
Execute the exact SQL in a fresh database/schema; serialize result rows with | separators- Container image ID
sha256:ec91410a8f6ec3e985830b5e3a0560306d36f8c1c5ccd91a6699abe707123fa3- Code SHA-256
efc6057423a369b482b21e0b59bd803f898a011c95b87e6883c3909317ac0ef1- Dependencies
- bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3
Test input setup
These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.
# No input files required.
Observed standard output
Ada|30 Grace|5 Lin|0
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.