Report duplicate business values and their frequency.
SQL: Group by a candidate business key and retain only groups with multiple rows.
CREATE TABLE scores (id INTEGER PRIMARY KEY, score INTEGER);
INSERT INTO scores VALUES (1,90),(2,90),(3,80),(4,70);
SELECT score,COUNT(*) FROM scores GROUP BY score HAVING COUNT(*)>1 ORDER BY score;Expected output EXAMPLE
90|2
Details
Run in a scratch SQL database. These portable examples are executed on both PostgreSQL and SQLite. Result rows below use | between columns, without headers; client display formatting may differ. Group by a candidate business key and retain only groups with multiple rows. 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; PostgreSQL 18.6 (Debian 18.6-1.pgdg13+2) · bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3; psycopg 3.2.10; pymssql 2.3.8
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. Database services use a private internal Docker network without published ports. Fresh scratch schema/database for each case; test database administrator credentials are confined to these disposable services. 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
f55f516d9f337e684eea6de93ce7cabc252930c41c509bc25bcd3b805c2b4cbe- Dependencies
- bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3; psycopg 3.2.10; pymssql 2.3.8
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
90|2
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.