ClickHouse

ClickHouse adapter for @dudousxd/nestjs-filter: compiles the structured input — filter / where operators, sort, paginate, search, distinct, select, cursor pages, groupByCount, extent — to one parameterized ClickHouse statement. Every client value is bound as a typed {pN:Type} query parameter; client-supplied field names only select among declared expressions. Nothing a client sends is ever part of the SQL text.

pnpm add @dudousxd/nestjs-filter @dudousxd/nestjs-filter-clickhouse @clickhouse/client

Declare a tableCopy Anchor Link

The table is the adapter's "entity". Its fields are the allowlist: a trusted SQL expression per field plus its ClickHouse type (which types every bound parameter).

import { defineClickHouseTable } from '@dudousxd/nestjs-filter-clickhouse';

export const events = defineClickHouseTable({
  table: 'events',
  primaryKey: 'id',
  where: 'at >= now64(3) - toIntervalDay(90)', // optional always-on guard (trusted SQL)
  fields: {
    id: 'UUID',
    at: "DateTime64(3, 'UTC')",
    day: { type: 'Date', expr: 'toDate(at)' },
    event: { type: 'LowCardinality(String)', expr: 'name' },
    provider: 'Nullable(String)',
    durationMs: 'UInt64',
    tags: 'Array(String)',
  },
});

Aggregated tables (measures)Copy Anchor Link

Fields marked measure are aggregate expressions. A table with measures answers with groups: rows are grouped by the requested dimensions (select, else the table's groupBy), a filter that touches a measure goes to HAVING, sorting by a measure orders groups, and the total counts groups.

export const chatDaily = defineClickHouseTable({
  table: 'chat_daily',
  groupBy: ['provider', 'model'],
  fields: {
    day: 'Date',
    provider: 'LowCardinality(String)',
    model: 'LowCardinality(String)',
    turns: { type: 'UInt64', expr: 'sum(turns)', measure: true },
    errorRate: { type: 'Float64', expr: 'sum(errors) / nullIf(sum(turns), 0)', measure: true },
  },
});

// GET /stats/chat?select=day&filter[provider]=openai&filter[where][0][field]=turns&filter[where][0][operator]=>=&filter[where][0][value]=100&sort=-turns

Register and queryCopy Anchor Link

import { createClient } from '@clickhouse/client';
import { clickHouseAdapter, ClickHouseFilter, type ClickHouseQuery } from '@dudousxd/nestjs-filter-clickhouse';

FilterModule.forRoot({ adapter: clickHouseAdapter({ client: createClient({ url }) }) });
// or { connection: CLICKHOUSE } — the token of a provider holding the client

@Injectable()
@Filterable({ entity: events, defaultSort: '-at' })
export class EventFilter extends ClickHouseFilter {
  static readonly search = ['event', 'provider'];

  @FilterFor('days')
  lastDays(value: string) {
    this.$query.where(`at >= now64(3) - toIntervalDay(${this.$query.bind('UInt32', Number(value))})`);
  }
}

@Get()
list(@ApplyFilter(EventFilter) q: ClickHouseQuery) {
  return q.executeAndCount(); // { rows, total }
}

q.toSQL() / q.toCountSQL() return { query, params } to run with any client. Next to a database adapter, provide ClickHouseAdapter under CLICKHOUSE_FILTER_ADAPTER and name it per filter: @Filterable({ entity: events, adapter: CLICKHOUSE_FILTER_ADAPTER }).

SemanticsCopy Anchor Link

The same answers as the SQL and memory adapters (Postgres as the reference):

• NULL logic — negated operators do not match NULL values. ClickHouse answers NULL NOT IN (…) with 1 (transform_null_in = 0), so notIn on a Nullable field adds isNotNull(…).
• Case & wildcards — contains/startsWith/endsWith are case-sensitive, iContains and search case-insensitive (UTF-8). Matching uses position()/startsWith(), not LIKE: % and _ in values are literal. Non-string fields are matched via toString().
• Coercion — values are encoded for the field type ('30' → UInt, 'true' → Bool, ISO strings → DateTime64 text in UTC); a value that does not fit is a 400 (ClickHouseValueError), not a failed query.
• isEmpty — NULL-or-'' on strings, NULL-or-[] on arrays, NULL elsewhere.
• Array fields — positive operators hold when any element matches (arrayExists), negated ones when none does.
• Ordering — NULLS LAST ascending, NULLS FIRST descending.
• Output columns are aliased __<field> in the SQL (ClickHouse resolves aliases inside WHERE and aggregates, so sum(errors) AS errors would recurse) and un-prefixed on execution.
• Computed fields — SQL expressions (strings, or functions returning a string).
• Not supported: relations / includes / to-many aggregates (ClickHouse has no correlated subqueries to build them on), tsvector search.

Result values are whatever JSONEachRow returns: 64-bit integers arrive as strings unless you set output_format_json_quote_64bit_integers: 0 on the client, and dates as text.

TestingCopy Anchor Link

pnpm test runs the SQL-snapshot suite. With a server, the real-server suite runs the cross-adapter contract's operator expectations against ClickHouse:

docker run -d --name ch -p 8123:8123 -e CLICKHOUSE_USER=test -e CLICKHOUSE_PASSWORD=test clickhouse/clickhouse-server:25.8
CLICKHOUSE_URL=http://test:test@localhost:8123 pnpm --filter @dudousxd/nestjs-filter-clickhouse test