ClickHouse

Connect to a ClickHouse database

ClickHouse is an open-source, column-oriented database management system for online analytical processing (OLAP). It is built for speed at scale — running aggregations and analytical queries over billions of rows in real time.

The ClickHouse block connects to any ClickHouse deployment (ClickHouse Cloud or self-hosted) over the HTTP interface. Use it to run analytical queries, stream rows into tables, manage schemas, inspect system state, and execute arbitrary SQL — all from within a workflow.

Connection details

Host — your ClickHouse hostname (e.g. your-instance.clickhouse.cloud or your server address).
Port — the HTTP interface port. Use 8443 for HTTPS (ClickHouse Cloud) or 8123 for plain HTTP (self-hosted).
Database / Username — default to default if not specified.
Password — optional for unauthenticated local instances.
Use HTTPS — keep enabled for any remote or Cloud instance.

Things to know

UPDATE and DELETE are implemented as ClickHouse mutations (ALTER TABLE ... UPDATE/DELETE). Mutations run asynchronously in the background, so the affected row count is not returned immediately.
ClickHouse is optimized for bulk inserts. Prefer batching many rows per insert over many single-row inserts.
The connection host is validated to block private/internal addresses, so the block cannot reach localhost or internal-only hosts.

Usage Instructions

Integrate ClickHouse into the workflow. Query and insert data, manage databases and tables, inspect schemas, monitor mutations and running queries, manage partitions, and execute raw SQL over the ClickHouse HTTP interface.

Tools

`clickhouse_query`

Execute a SELECT query on a ClickHouse database

Input

Parameter	Type	Required	Description
`host`	string	Yes	ClickHouse server hostname (e.g., your-instance.clickhouse.cloud)
`port`	number	Yes	ClickHouse HTTP interface port (8443 for HTTPS, 8123 for HTTP)
`database`	string	Yes	Database name to connect to
`username`	string	Yes	ClickHouse username
`password`	string	No	ClickHouse password
`secure`	boolean	No	Use a secure HTTPS connection (default: true)
`query`	string	Yes	SQL SELECT query to execute

Output

Parameter	Type	Description
`message`	string	Operation status message
`rows`	array	Array of rows returned from the query
`rowCount`	number	Number of rows returned

`clickhouse_execute`

Execute raw SQL (DDL, mutations, or queries) on a ClickHouse database

Input

Parameter	Type	Required	Description
`host`	string	Yes	ClickHouse server hostname (e.g., your-instance.clickhouse.cloud)
`port`	number	Yes	ClickHouse HTTP interface port (8443 for HTTPS, 8123 for HTTP)
`database`	string	Yes	Database name to connect to
`username`	string	Yes	ClickHouse username
`password`	string	No	ClickHouse password
`secure`	boolean	No	Use a secure HTTPS connection (default: true)
`query`	string	Yes	Raw SQL statement to execute

Output

Parameter	Type	Description
`message`	string	Operation status message
`rows`	array	Array of rows returned from the statement
`rowCount`	number	Number of rows returned or affected

`clickhouse_insert`

Insert a row into a ClickHouse table

Input

Parameter	Type	Required	Description
`host`	string	Yes	ClickHouse server hostname (e.g., your-instance.clickhouse.cloud)
`port`	number	Yes	ClickHouse HTTP interface port (8443 for HTTPS, 8123 for HTTP)
`database`	string	Yes	Database name to connect to
`username`	string	Yes	ClickHouse username
`password`	string	No	ClickHouse password
`secure`	boolean	No	Use a secure HTTPS connection (default: true)
`table`	string	Yes	Table name to insert data into
`data`	object	Yes	Data object to insert (key-value pairs mapping column names to values)

Output

Parameter	Type	Description
`message`	string	Operation status message
`rows`	array	Inserted rows (empty for ClickHouse inserts)
`rowCount`	number	Number of rows inserted

`clickhouse_insert_rows`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_update`

Update rows in a ClickHouse table via an ALTER TABLE ... UPDATE mutation

Input

Parameter	Type	Required	Description
`host`	string	Yes	ClickHouse server hostname (e.g., your-instance.clickhouse.cloud)
`port`	number	Yes	ClickHouse HTTP interface port (8443 for HTTPS, 8123 for HTTP)
`database`	string	Yes	Database name to connect to
`username`	string	Yes	ClickHouse username
`password`	string	No	ClickHouse password
`secure`	boolean	No	Use a secure HTTPS connection (default: true)
`table`	string	Yes	Table name to update data in
`data`	object	Yes	Data object with fields to update (key-value pairs)
`where`	string	Yes	WHERE clause condition (without the WHERE keyword)

Output

Parameter	Type	Description
`message`	string	Operation status message
`rows`	array	Updated rows (empty for ClickHouse mutations)
`rowCount`	number	Number of rows written by the mutation

`clickhouse_delete`

Delete rows from a ClickHouse table via an ALTER TABLE ... DELETE mutation

Input

Parameter	Type	Required	Description
`host`	string	Yes	ClickHouse server hostname (e.g., your-instance.clickhouse.cloud)
`port`	number	Yes	ClickHouse HTTP interface port (8443 for HTTPS, 8123 for HTTP)
`database`	string	Yes	Database name to connect to
`username`	string	Yes	ClickHouse username
`password`	string	No	ClickHouse password
`secure`	boolean	No	Use a secure HTTPS connection (default: true)
`table`	string	Yes	Table name to delete data from
`where`	string	Yes	WHERE clause condition (without the WHERE keyword)

Output

Parameter	Type	Description
`message`	string	Operation status message
`rows`	array	Deleted rows (empty for ClickHouse mutations)
`rowCount`	number	Number of rows affected by the mutation

`clickhouse_list_databases`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_list_tables`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_describe_table`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_show_create_table`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_count_rows`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_introspect`

Introspect a ClickHouse database to retrieve table structures, columns, and engines

Input

Parameter	Type	Required	Description
`host`	string	Yes	ClickHouse server hostname (e.g., your-instance.clickhouse.cloud)
`port`	number	Yes	ClickHouse HTTP interface port (8443 for HTTPS, 8123 for HTTP)
`database`	string	Yes	Database name to introspect
`username`	string	Yes	ClickHouse username
`password`	string	No	ClickHouse password
`secure`	boolean	No	Use a secure HTTPS connection (default: true)

Output

Parameter	Type	Description
`message`	string	Operation status message
`tables`	array	Array of table schemas with columns and engines
↳ `name`	string	Table name
↳ `database`	string	Database the table belongs to
↳ `engine`	string	Table engine (e.g., MergeTree, Log)
↳ `totalRows`	number	Approximate total number of rows in the table
↳ `columns`	array	Table columns
↳ `name`	string	Column name
↳ `type`	string	ClickHouse data type (e.g., UInt32, String, DateTime)
↳ `defaultKind`	string	Kind of default expression (DEFAULT, MATERIALIZED, ALIAS)
↳ `defaultExpression`	string	Default value expression for the column
↳ `isInPrimaryKey`	boolean	Whether the column is part of the primary key
↳ `isInSortingKey`	boolean	Whether the column is part of the sorting key

`clickhouse_create_database`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_drop_database`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_create_table`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_drop_table`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_truncate_table`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_rename_table`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_optimize_table`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_list_partitions`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_drop_partition`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_list_mutations`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_list_running_queries`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_kill_query`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_table_stats`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

`clickhouse_list_clusters`

Input

Parameter	Type	Required	Description

Output

Parameter	Type	Description
`message`	string	Success or error message describing the operation outcome
`rows`	array	Array of rows returned from the operation
`rowCount`	number	Number of rows returned or affected by the operation
`count`	number	Row count (count rows operation)
`ddl`	string	CREATE TABLE statement (show create table operation)
`tables`	array	Array of table schemas with columns and engines (introspect operation)

On this page

Usage Instructions

clickhouse_query

clickhouse_execute

clickhouse_insert

clickhouse_insert_rows

clickhouse_update

clickhouse_delete

clickhouse_list_databases

clickhouse_list_tables

clickhouse_describe_table

clickhouse_show_create_table

clickhouse_count_rows

clickhouse_introspect

clickhouse_create_database

clickhouse_drop_database

clickhouse_create_table

clickhouse_drop_table

clickhouse_truncate_table

clickhouse_rename_table

clickhouse_optimize_table

clickhouse_list_partitions

clickhouse_drop_partition

clickhouse_list_mutations

clickhouse_list_running_queries

clickhouse_kill_query

clickhouse_table_stats

clickhouse_list_clusters