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Run a query

The /query resource lets you stream the output records of a SELECT statement via a chunked transfer encoding. The response is streamed back until the LIMIT specified in the statement is reached, or the client closes the connection. If no LIMIT is specified in the statement, then the response is streamed until the client closes the connection.

POST /query

Run a SELECT statement and stream back the results.

JSON Parameters:

  • ksql (string): The SELECT statement to run.
  • streamsProperties (map): Property overrides to run the statements with. Refer to the Config Reference for details on properties that you can set.
  • streamsProperties[property-name] (string): The value of the property named by property-name. Both the value and property-name should be strings.

Each response chunk is a JSON object with the following format:

Response JSON Object:

  • row (object): A single row being returned. This will be null if an error is being returned.
  • row.columns (array): The values contained in the row.
  • row.columns[i] (?): The value contained in a single column for the row. The value type depends on the type of the column.
  • finalMessage (string): If this field is non-null, it contains a final message from the server. No additional rows will be returned and the server will end the response.
  • errorMessage (string): If this field is non-null, an error has been encountered while running the statement. No additional rows are returned and the server will end the response.

Examples

Example curl command

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curl -X "POST" "http://<ksqldb-host-name>:8088/query" \
     -d $'{
  "ksql": "SELECT * FROM USERS EMIT CHANGES;",
  "streamsProperties": {}
}'

Example request

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POST /query HTTP/1.1
Accept: application/vnd.ksql.v1+json
Content-Type: application/vnd.ksql.v1+json

{
  "ksql": "SELECT * FROM pageviews EMIT CHANGES;",
  "streamsProperties": {
    "ksql.streams.auto.offset.reset": "earliest"
  }
}

Example response

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HTTP/1.1 200 OK
Content-Type: application/vnd.ksql.v1+json
Transfer-Encoding: chunked

...
{"row":{"columns":[1524760769983,"1",1524760769747,"alice","home"]},"errorMessage":null}
...
Last update: 2021-02-09