clickhouse.md

id	title
clickhouse	ClickHouse

ClickHouse

ToolJet can connect to the ClickHouse to read and write data.

:::info ToolJet uses this NodeJS client for ClickHouse. :::

Connection

To establish a connection with the Clickhouse data source, you can either click on the +Add new data source button located on the query panel or navigate to the Data Sources page through the ToolJet dashboard.

ToolJet requires the following to connect to your ClickHouse Database:

• Username
• Password
• Host
• Port
• Database Name
• Protocol
• Use Post
• Trim Query
• Use Gzip
• Debug
• Raw

Querying ClickHouse

After setting up the ClickHouse data source, you can click on the + button of the query manager and select the ClickHouse data source that you added in the previous step to create a new query.

:::info For more details on clickhouse visit Clickhouse docs. :::

Supported Operations:

• SQL Query
• Insert array of objects

SQL Query

Use this to operation to enter ClickHouse SQL Statements. These statements represent various kinds of action you can perform using SQL queries.

Example SQL queries

• SELECT:

   SELECT * from test array;

  

• CREATE:

   CREATE TABLE test array3 (
   	date Date,
   	str String,
   	arr Array(String),
   	arr2 Array (Date)
   	arr3 Array(UInt32) ,
   	id1 UUID
   )ENGINE=MergeTree () ORDER BY(str)

  

• ALTER TABLE(add column)

   ALTER TABLE test array1 ADD COLUMN Added2 UInt32;

  

• SELECT WITH WHERE CLAUSE

   SELECT * FROM test array1 WHERE str='Somethingl...'

  

• UPDATE

   ALTER TABLE test_array1 UPDATE arr = (12] WHERE str='Somethingl...'

  

• DELETE

   ALTER TABLE test_array1 DELETE WHERE str= 'Somethingl...'

  

• NORMAL INSERT

  1. Step 1 - Creating Table

   CREATE TABLE test array4 (
   name String,
   date Date
  )ENGINE=MergeTree () ORDER BY (name)

  
  2. Step 2 - Insert

   INSERT INTO test_array4 (*) VALUES ('juvane', '1996-01-13')

  

  :::info Giving Primary Key

   CREATE TABLE db.table_name
   (
   	name1 type1, name2 type2, ...,
   	PRIMARY KEY(expr1[, expr2,...])]
   )
   ENGINE = engine;
  
   OR 
   
   CREATE TABLE db.table_name
   (
   	name1 type1, name2 type2, ...
   )
   ENGINE = engine
   PRIMARY KEY(expr1[, expr2,...]);
  

  :::

Insert array of objects

Use this operation for inserting array of objects.

Required Parameters:

• Body
• Fields
• Table name

Example Body value:

[
			{
				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'
			}
		];