clickhouse

NodeJS client for ClickHouse.
Send query over HTTP interface.

Install:

``bash
npm i clickhouse
`

Example:

`javascript
const { ClickHouse } = require('clickhouse');

const clickhouse = new ClickHouse();
`
or with all options:

`javascript
const clickhouse = new ClickHouse({
url: 'http://localhost',
port: 8123,
debug: false,
basicAuth: null,
isUseGzip: false,
trimQuery: false,
usePost: false,
format: "json", // "json" || "csv" || "tsv"
raw: false,
config: {
session_id : 'session_id if neeed',
session_timeout : 60,
output_format_json_quote_64bit_integers : 0,
enable_http_compression : 0,
database : 'my_database_name',
},

// This object merge with request params (see request lib docs)
reqParams: {
...
}
});
`

or change

basicAuth: null
to

basicAuth: {
username: 'default',
password: '',
},


*

Exec query:
`javascript
const queries = [
'DROP TABLE IF EXISTS session_temp',

CREATE TABLE session_temp (
date Date,
time DateTime,
mark String,
ips Array(UInt32),
queries Nested (
act String,
id UInt32
)
)
ENGINE=MergeTree(date, (mark, time), 8192),

'OPTIMIZE TABLE ukit.loadstat PARTITION 201807 FINAL'
];

for(const query of queries) {
const r = await clickhouse.query(query).toPromise();

console.log(query, r);
}
``

*

Exec by callback way:
`javascript
clickhouse.query(query).exec(function (err, rows) {
...
});
``

*

Stream:
`javascript
clickhouse.query(SELECT number FROM system.numbers LIMIT 10).stream()
.on('data', function() {
const stream = this;

stream.pause();

setTimeout(() => {
stream.resume();
}, 1000);
})
.on('error', err => {
...
})
.on('end', () => {
...
});
`

or async stream:
`javascript
// async iteration
for await (const row of clickhouse.query(sql).stream()) {
console.log(row);
}
`

*

As promise:
`javascript
const rows = await clickhouse.query(query).toPromise();

// use query with external data
const rows = await clickhouse.query('SELECT * AS count FROM temp_table', {
external: [
{
name: 'temp_table',
data: e._.range(0, rowCount).map(i => str${i})
},
]
}).toPromise();
`

*

Set session:
`javascript
clickhouse.sessionId = '...';
const r = await clickhouse.query(
CREATE TEMPORARY TABLE test_table
(_id String, str String)
ENGINE=Memory
).toPromise();
``

In case your application requires specific sessions to manage specific data then you can send session_id with each query.

`javascript
let mySessionId = 'some_randome_string';
const r = await clickhouse.query(
CREATE TEMPORARY TABLE test_table
(_id String, str String)
ENGINE=Memory, {}, {sessionId: mySessionId}
).toPromise();
`

Insert stream:
`javascript
const ws = clickhouse.insert('INSERT INTO session_temp').stream();
for(let i = 0; i <= 1000; i++) {
await ws.writeRow(
[
e._.range(0, 50).map(
j => ${i}:${i * 2}:${j}
).join('-')
]
);
}

//wait stream finish
const result = await ws.exec();
`

*

Pipe readable stream to writable stream (across transform):
`javascript
const rs = clickhouse.query(query).stream();

const tf = new stream.Transform({
objectMode : true,
transform : function (chunk, enc, cb) {
cb(null, JSON.stringify(chunk) + '\n');
}
});

clickhouse.sessionId = Date.now();
const ws = clickhouse.insert('INSERT INTO session_temp2').stream();

const result = await rs.pipe(tf).pipe(ws).exec();
`
*

insert array of objects:
`javascript

/*
CREATE TABLE IF NOT EXISTS test_array (
date Date,
str String,
arr Array(String),
arr2 Array(Date),
arr3 Array(UInt8),
id1 UUID
) ENGINE=MergeTree(date, date, 8192)
*/
const rows = [
{
date: '2018-01-01',
str: 'Something1...',
arr: [],
arr2: ['1985-01-02', '1985-01-03'],
arr3: [1,2,3,4,5],
id1: '102a05cb-8aaf-4f11-a442-20c3558e4384'
},

{
date: '2018-02-01',
str: 'Something2...',
arr: ['5670000000', 'Something3...'],
arr2: ['1985-02-02'],
arr3: [],
id1: 'c2103985-9a1e-4f4a-b288-b292b5209de1'
}
];

await clickhouse.insert(
insert into test_array
(date, str, arr, arr2,
arr3, id1),
rows
).toPromise();
`
*

Parameterized Values:
`javascript
const rows = await clickhouse.query(
'SELECT * AS count FROM temp_table WHERE version = {ver:UInt16}',
{
params: {
ver: 1
},
}
).toPromise();
`
For more information on encoding in the query, see this section of the ClickHouse documentation.

*

Run Tests:

`
npm install
npm run test


or

node_modules/.bin/mocha --timeout 60000 --slow 5000 -f "SPECIFIC TEST NAME"

``

*

Changelogs:
* 2020-08-26 (v2.6.0)
- A lot of PRs from community
* 2020-11-02 (v2.4.1)
- Merge list of PR
- fix test with Base Auth check
* 2020-11-02 (v2.2.0) ___Backward Incompatible Change___
- port from url more important than port from config
* 2020-04-17 (v2.1.0)
- Fix query with totals. For json formats work perfect, but for another - doesn't
* 2019-02-13
- Add compatibility with user and username options
* 2019-02-07
- Add TLS/SSL Protocol support
- Add async iteration over SELECT



Links
* request lib doc https://github.com/request/request#requestoptions-callback