streams.md

Streams management

The eKuiper stream command line tools allows you to manage the streams, such as create, describe, show and drop stream definitions.

create a stream

The command is used for creating a stream. For more detailed information of stream definition, please refer to streams.

create stream $stream_name '$stream_def' | create stream -f $stream_def_file

• Specify the stream definition in command line.

Sample:

# bin/kuiper create stream my_stream '(id bigint, name string, score float) WITH ( datasource = "topic/temperature", FORMAT = "json", KEY = "id")'
stream my_stream created

The command create a stream named my_stream.

• Specify the stream definition in file. If the stream is complex, or the stream is already wrote in text files with well organized formats, you can just specify the stream definition through -f option.

Sample:

# bin/kuiper create stream -f /tmp/my_stream.txt
stream my_stream created

Below is the contents of my_stream.txt.

my_stream(id bigint, name string, score float)
    WITH ( datasource = "topic/temperature", FORMAT = "json", KEY = "id");

show streams

The command is used for displaying all of streams defined in the server.

show streams

Sample:

# bin/kuiper show streams
my_stream

describe a stream

The command is used for print the detailed definition of stream.

describe stream $stream_name

Sample:

# bin/kuiper describe stream my_stream
Fields
--------------------------------------------------------------------------------
id  bigint
name  string
score  float

FORMAT: json
KEY: id
DATASOURCE: topic/temperature

drop a stream

The command is used for drop the stream definition.

drop stream $stream_name

Sample:

# bin/kuiper drop stream my_stream
stream my_stream dropped

query against streams

The command is used for querying data from stream.

query

Sample:

# bin/kuiper query
kuiper > 

After typing query sub-command, it prompts kuiper >, then type SQLs (see eKuiper SQL reference for how to use eKuiper SQL) in the command prompt and press enter.

The results will be print in the console.

kuiper > SELECT * FROM my_stream WHERE id > 10;
[{"...":"..." ....}]
...

• Press CTRL + C to stop the query;

• If no SQL are type, you can type quit or exit to quit the kuiper prompt console.