Bind inferred ClickHouse numbers with fraction-preserving types

[fubhy]

Summary

Ordinary fractional JavaScript numbers are compiled as bare Decimal parameters, whose Decimal(10, 0) semantics discard fractional digits.

Important

This PR starts with focused failing reproduction tests. Add the implementation fix to this same branch; CI is expected to fail until that fix is included.

Fractional numbers bind as scale-zero Decimal values

Module: clickhouse/ClickhouseClient
Audit ID: sql-adapters-ch-3
Severity / confidence: high / high

What happens

Ordinary fractional JavaScript numbers are compiled as bare Decimal parameters, whose Decimal(10, 0) semantics discard fractional digits.

Why it happens

Every inferred number uses ClickHouse Decimal rather than a fraction-preserving type such as Float64.

Expected behavior

Default interpolation must preserve finite JavaScript numbers unless the caller explicitly selects a narrower parameter type.

Relevant implementation

These links and excerpts are pinned to audit base c9b56ab507f224426ee8388dc450da447ec4715f.

• packages/sql/clickhouse/src/ClickhouseClient.ts:477-499
• packages/sql/clickhouse/src/ClickhouseClient.ts:510-527

View problematic code at packages/sql/clickhouse/src/ClickhouseClient.ts:477-499

const typeFromUnknown = (value: unknown): string => {
  if (Statement.isFragment(value)) {
    return typeFromUnknown(value.segments[0])
  } else if (isClickhouseParam(value)) {
    return value.paramA
  } else if (Array.isArray(value)) {
    return `Array(${typeFromUnknown(value[0])})`
  }
  switch (typeof value) {
    case "number":
      return "Decimal"
    case "bigint":
      return "Int64"
    case "boolean":
      return "Bool"
    case "object":
      if (value instanceof Date) {
        return "DateTime()"
      }
      return "String"
    default:
      return "String"
  }

View exact lines on GitHub

View problematic code at packages/sql/clickhouse/src/ClickhouseClient.ts:510-527

export const makeCompiler = (transform?: (_: string) => string) =>
  Statement.makeCompiler<ClickhouseCustom>({
    dialect: "sqlite",
    placeholder(i, u) {
      return `{p${i}: ${typeFromUnknown(u)}}`
    },
    onIdentifier: transform ?
      function(value, withoutTransform) {
        return withoutTransform ? escape(value) : escape(transform(value))
      } :
      escape,
    onRecordUpdate() {
      return ["", []]
    },
    onCustom(type, placeholder) {
      return [placeholder(type), [type.paramB]]
    }
  })

View exact lines on GitHub

Reproduction

pnpm test --run packages/sql/clickhouse/test/NumberBindingRepro.test.ts

Observed failure: FAIL: the compiler emitted bare Decimal instead of Float64.

Implementation handoff

The initial reproduction tests on this branch are the regression specification for the implementation fix that should follow in this PR.

1. Start with the pinned implementation excerpts and the Why it happens analysis above.
2. Change the implementation so it satisfies the stated Expected behavior; do not weaken or remove the reproduction assertions.
3. Run the focused reproduction command(s) and confirm the observed failures become passing tests:

pnpm test --run packages/sql/clickhouse/test/NumberBindingRepro.test.ts

4. Run the affected package's existing tests, then the repository lint and type checks before requesting review.

Audit provenance

• Audit base: c9b56ab507f224426ee8388dc450da447ec4715f
• Reproduction base: c9b56ab507f224426ee8388dc450da447ec4715f
• Findings: sql-adapters-ch-3
• Initial patch: focused reproduction tests; implementation fix pending

Closes EFF-342

[changeset-bot]

🦋 Changeset detected

Latest commit: 41fd1e3

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 30 packages

Name	Type
@effect/sql-clickhouse	Patch
effect	Patch
@effect/opentelemetry	Patch
@effect/platform-browser	Patch
@effect/platform-bun	Patch
@effect/platform-deno	Patch
@effect/platform-node-shared	Patch
@effect/platform-node	Patch
@effect/vitest	Patch
@effect/ai-anthropic	Patch
@effect/ai-openai-compat	Patch
@effect/ai-openai	Patch
@effect/ai-openrouter	Patch
@effect/atom-react	Patch
@effect/atom-solid	Patch
@effect/atom-vue	Patch
@effect/sql-d1	Patch
@effect/sql-libsql	Patch
@effect/sql-mssql	Patch
@effect/sql-mysql2	Patch
@effect/sql-pg	Patch
@effect/sql-pglite	Patch
@effect/sql-sqlite-bun	Patch
@effect/sql-sqlite-do	Patch
@effect/sql-sqlite-node	Patch
@effect/sql-sqlite-react-native	Patch
@effect/sql-sqlite-wasm	Patch
@effect/docgen	Patch
@effect/doctest	Patch
@effect/openapi-generator	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pullfrog]

✅ No new issues found.

Reviewed changes

• Reproduction test for ClickHouse fractional-number binding — adds NumberBindingRepro.test.ts that constructs a Statement-backed compiler, compiles sql`SELECT ${1.5}`, and asserts the placeholder is {p1: Float64}. Confirmed to fail against the current code (which emits Decimal for all number values at ClickhouseClient.ts:487).

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[pullfrog]

✅ No new issues found.

Reviewed changes — since the prior review at c64d7de:

• Changed inferred number type from Decimal to Float64 — typeFromUnknown in ClickhouseClient.ts:487 now maps all JavaScript number values to Float64, which faithfully preserves fractional digits unlike the previous bare Decimal (which had Decimal(10, 0) semantics that discarded them).
• Relocated the reproduction test — merged the standalone NumberBindingRepro.test.ts into Client.test.ts, replacing the stub "should work" test with the fractional-number assertion.
• Added changeset — patch release note for @effect/sql-clickhouse.

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[github-actions]

Bundle Size Analysis

Generated from PR build output; treat the content below as untrusted.

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batching.ts	9.86 KB	9.86 KB	0.00 KB (0.00%)
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config.ts	20.60 KB	20.60 KB	0.00 KB (0.00%)
differ.ts	20.20 KB	20.20 KB	0.00 KB (0.00%)
http-client.ts	21.49 KB	21.49 KB	0.00 KB (0.00%)
logger.ts	10.76 KB	10.76 KB	0.00 KB (0.00%)
metric.ts	8.99 KB	8.99 KB	0.00 KB (0.00%)
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