fix(adapter-mariadb,adapter-planetscale): return strings for text columns with binary collation in raw queries by sakurai-ryo · Pull Request #29238 · prisma/prisma

sakurai-ryo · 2026-02-23T09:10:06Z

Summary

adapter-mariadb

Replace the BINARY_FLAG check with a collation index check (collation.index === 63), matching the approach used by mariadb-connector-nodejs.
https://github.com/mariadb-corporation/mariadb-connector-nodejs/blob/3.5.1/lib/cmd/decoder/text-decoder.js#L44

adapter-planetscale

Add a charset-based collation check (field.charset !== 63) in fieldToColumnType to distinguish text columns from true binary columns. Vitess converts CHAR/VARCHAR/TEXT columns with a binary collation to BINARY/VARBINARY/BLOB respectively, so the charset value is used to detect this conversion.
https://github.com/planetscale/database-js/blob/de78eebfaec8cd88c670b8c644fc5a3fd69e664c/src/cast.ts#L92

Root cause

Because the mapColumnType function in adapter-mariadb returns ColumnTypeEnum.Bytes when a column has a Binary Collation,
https://github.com/prisma/prisma/blob/7.4.1/packages/adapter-mariadb/src/conversion.ts#L86

and the fieldToColumnType function in adapter-planetscale does not inspect the charset at all for BLOB/BINARY/VARBINARY types,
https://github.com/prisma/prisma/blob/7.4.1/packages/adapter-planetscale/src/conversion.ts#L85

the deserializeValue function unintentionally converts even string data into a Uint8Array, treating it as a base64 string.
https://github.com/prisma/prisma/blob/7.4.1/packages/client/src/runtime/utils/deserializeRawResults.ts#L20

Since a Binary Collation can also apply to string data types like CHAR, the type determination logic in both adapter-mariadb and adapter-planetscale needs to be updated.

Summary by CodeRabbit

Bug Fixes
- Improved binary collation detection in MariaDB and PlanetScale database adapters. Columns with binary collation now correctly return as text data.
Tests
- Added MySQL column type tests to validate binary collation handling in query results.

…lation in raw queries

CLAassistant · 2026-02-23T09:10:14Z

All committers have signed the CLA.

codspeed-hq · 2026-02-24T10:45:21Z

Merging this PR will not alter performance

✅ 17 untouched benchmarks
⏩ 30 skipped benchmarks¹

_{Comparing sakurai-ryo:fix-mysql-bin (c5b5acf) with main (4a48ecc)}

30 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

jacek-prisma · 2026-02-25T13:38:24Z

The newly added test is failing for planetscale

…lation in MySQL

coderabbitai · 2026-02-26T11:06:21Z

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📥 Commits

Reviewing files that changed from the base of the PR and between c61292b and c5b5acf.

📒 Files selected for processing (6)

packages/adapter-mariadb/src/conversion.ts
packages/adapter-planetscale/src/conversion.ts
packages/adapter-planetscale/src/planetscale.ts
packages/client/tests/functional/raw-queries/mysql-column-type/_matrix.ts
packages/client/tests/functional/raw-queries/mysql-column-type/prisma/_schema.ts
packages/client/tests/functional/raw-queries/mysql-column-type/test.ts

Walkthrough

Fixes a bug where $queryRaw returns Uint8Array instead of strings for text columns with binary collation. Updates MariaDB and PlanetScale adapters to use collation-index-based checks instead of BINARY_FLAG for type detection. Refactors PlanetScale adapter's public API. Adds MySQL functional tests to verify correct string handling.

Changes

Cohort / File(s)	Summary
MariaDB Adapter `packages/adapter-mariadb/src/conversion.ts`	Replaces BINARY_FLAG-based detection with collation-index check (BINARY_COLLATION_INDEX = 63) to accurately distinguish binary from text columns with binary collation.
PlanetScale Adapter `packages/adapter-planetscale/src/conversion.ts`, `packages/adapter-planetscale/src/planetscale.ts`	Introduces collation-index-based binary detection, refactors fieldToColumnType to accept Field objects instead of PlanetScaleColumnType, removes PlanetScaleColumnType from public exports, and updates integration to pass full field objects.
MySQL Column Type Tests `packages/client/tests/functional/raw-queries/mysql-column-type/_matrix.ts`, `prisma/_schema.ts`, `test.ts`	Adds functional test suite for MySQL with test matrix, schema definition, and tests verifying text columns with binary collation (utf8mb4_bin) return strings rather than Uint8Array.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main changes: fixing binary collation handling in both adapter-mariadb and adapter-planetscale to return strings for text columns.
Linked Issues check	✅ Passed	The PR implements the required change from issue `#29237`: replacing BINARY_FLAG checks with collation-index checks (collation.index === 63) in both adapters, and adds functional tests validating strings are returned for text columns with binary collation.
Out of Scope Changes check	✅ Passed	The PR includes changes to adapter-mariadb and adapter-planetscale conversion logic as required, plus related updates to planetscale.ts to use the new function signature, and adds necessary functional tests for MySQL.

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sakurai-ryo · 2026-02-26T12:07:05Z

I added some fixes to adapter-planetscale as well.

…umns with binary collation in raw queries (#29238) Fixes #29237 ## Summary ### adapter-mariadb Replace the `BINARY_FLAG` check with a collation index check (`collation.index === 63`), matching the approach used by `mariadb-connector-nodejs`. https://github.com/mariadb-corporation/mariadb-connector-nodejs/blob/3.5.1/lib/cmd/decoder/text-decoder.js#L44 ### adapter-planetscale Add a charset-based collation check (`field.charset !== 63`) in `fieldToColumnType` to distinguish text columns from true binary columns. Vitess converts CHAR/VARCHAR/TEXT columns with a binary collation to BINARY/VARBINARY/BLOB respectively, so the charset value is used to detect this conversion. https://github.com/planetscale/database-js/blob/de78eebfaec8cd88c670b8c644fc5a3fd69e664c/src/cast.ts#L92 ## Root cause Because the `mapColumnType` function in `adapter-mariadb` returns `ColumnTypeEnum.Bytes` when a column has a Binary Collation, https://github.com/prisma/prisma/blob/7.4.1/packages/adapter-mariadb/src/conversion.ts#L86 and the `fieldToColumnType` function in `adapter-planetscale` does not inspect the charset at all for BLOB/BINARY/VARBINARY types, https://github.com/prisma/prisma/blob/7.4.1/packages/adapter-planetscale/src/conversion.ts#L85 the `deserializeValue` function unintentionally converts even string data into a `Uint8Array`, treating it as a base64 string. https://github.com/prisma/prisma/blob/7.4.1/packages/client/src/runtime/utils/deserializeRawResults.ts#L20 Since a Binary Collation can also apply to string data types like `CHAR`, the type determination logic in both `adapter-mariadb` and `adapter-planetscale` needs to be updated.  ## Summary by CodeRabbit * **Bug Fixes** * Improved binary collation detection in MariaDB and PlanetScale database adapters. Columns with binary collation now correctly return as text data. * **Tests** * Added MySQL column type tests to validate binary collation handling in query results.

fix(adapter-mariadb): return strings for text columns with binary col…

dc44ec1

…lation in raw queries

fix(adapter-planetscale): improve column type handling for binary col…

c5b5acf

…lation in MySQL

sakurai-ryo changed the title ~~fix(adapter-mariadb): return strings for text columns with binary collation in raw queries~~ fix(adapter-mariadb,adapter-planetscale): return strings for text columns with binary collation in raw queries Feb 26, 2026

jacek-prisma approved these changes Feb 26, 2026

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jacek-prisma merged commit 76bb95b into prisma:main Feb 26, 2026
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fix(adapter-mariadb,adapter-planetscale): return strings for text columns with binary collation in raw queries#29238

fix(adapter-mariadb,adapter-planetscale): return strings for text columns with binary collation in raw queries#29238
jacek-prisma merged 2 commits intoprisma:mainfrom
sakurai-ryo:fix-mysql-bin

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Summary

adapter-mariadb

adapter-planetscale

Root cause

Summary by CodeRabbit

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Merging this PR will not alter performance

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