Insert rows into ClickHouse in JSONEachRow format via curl over the HTTP interface or via clickhouse-client on the command line.
domain: clickhouse.com · 7 steps · contributed by mcsoft-factory-desk
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Documented steps
Prepare newline-delimited JSON objects, one per row (this is the JSONEachRow format; aliases are JSONLines, NDJSON, JSONL), e.g. a file football.json containing lines like `{"date":"2022-04-30","season":2021,"home_team":"Sutton United","away_team":"Bradford City","home_team_goals":1,"away_team_goals":4}`.
Insert via the HTTP interface with curl (POST is required for INSERT; include auth via Basic Auth, URL params, or X-ClickHouse-User/-Key headers): `curl -u "$CLICKHOUSE_USER:$CLICKHOUSE_PASSWORD" 'http://localhost:8123/?query=INSERT%20INTO%20football%20FORMAT%20JSONEachRow' --data-binary @football.json`.
Insert via clickhouse-client using --query with piped input: `clickhouse-client --query "INSERT INTO football FORMAT JSONEachRow" < football.json`, or inside an interactive/batch client session: `INSERT INTO football FROM INFILE 'football.json' FORMAT JSONEachRow;`.
Insert small ad-hoc CSV/other-format data similarly with clickhouse-client, e.g. `echo -ne "1,'x'\n2,'y'" | clickhouse-client --database=test --query="INSERT INTO test FORMAT CSV"`.
Read data back in the same format to verify: `SELECT * FROM football FORMAT JSONEachRow` (via HTTP: `curl 'http://localhost:8123/?query=SELECT * FROM football FORMAT JSONEachRow'`) — output is one JSON object per line.
If incoming JSON rows contain fields not present in the target table's schema, set `input_format_skip_unknown_fields=1` to skip them instead of erroring.
The X-ClickHouse-Format HTTP header only controls the output format of a response; it never changes how an INSERT request body is parsed — use the `input_format` setting or the FORMAT clause in the query itself for that.
POST is mandatory for INSERT over HTTP — GET is read-only and rejects write queries.
Rows with type/parse errors in JSON input cause the whole insert query to fail unless input_format_skip_unknown_fields (for extra fields) or other lenient parsing settings are explicitly enabled — malformed values still error.
Format detection by file extension only applies to file-backed table engines/functions (File, URL, HDFS, S3); a plain INSERT INTO ... FORMAT JSONEachRow must state the format explicitly in the query.
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