Return 400 instead of 500 when query name/description exceed column limits

[ekanshul]

What type of PR is this?

• Bug Fix

Description

Fixes #7478.

Creating (or updating) a query with a name longer than 255 characters returned a 500: the handler passed the value straight through to the database, where the insert failed with psycopg2.errors.StringDataRightTruncation (value too long for type character varying(255)). The same applies to description (varchar(4096)).

This adds a small require_valid_field_lengths() check in redash/handlers/queries.py, used by both QueryListResource.post (create) and QueryResource.post (update). It reads the maximum lengths from the model's column definitions (no duplicated magic numbers) and aborts with 400 and a message like Query name must be at most 255 characters long.

How is this tested?

• Unit tests (pytest, jest)

New tests in tests/handlers/test_queries.py:

• TestQueryListResourcePost::test_rejects_too_long_name
• TestQueryListResourcePost::test_rejects_too_long_description
• TestQueryResourcePost::test_update_query_rejects_too_long_name

Before the fix these fail with sqlalchemy.exc.DataError (the 500 from the issue); with the fix pytest tests/handlers/test_queries.py passes (37 passed). ruff check and black --check are clean.

Related Tickets & Documents

#7478

Mobile & Desktop Screenshots/Recordings (if there are UI changes)

N/A (backend only)

[greptile-apps]

Greptile Summary

The PR prevents oversized query names and descriptions from reaching PostgreSQL by validating them against the SQLAlchemy column limits during query creation and updates.

• Adds shared model-derived length validation for name and description.
• Applies validation to the primary query create and update endpoints.
• Adds handler tests covering oversized names and descriptions.

Confidence Score: 5/5

The PR appears safe to merge with no actionable defects identified in the changed paths.

The validation uses the current model column limits, covers both primary creation and update handlers before persistence, and is backed by focused regression tests.

Important Files Changed

Filename	Overview
redash/handlers/queries.py	Adds correctly placed validation against the existing 255-character name and 4096-character description limits.
tests/handlers/test_queries.py	Adds focused regression coverage for oversized fields on query creation and update.

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[cubic-dev-ai]

No issues found across 2 files

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