Added a fallback mechanism for the reading metadata

[zaleslaw]

Fixes #1220 + some discovered bugs regarding type mappings

[zaleslaw]

@copilot make a review of fallback mechanism from the point of supporting some JDBC sources which are not supported yet

[Copilot]

@zaleslaw I've opened a new pull request, #1589, to work on those changes. Once the pull request is ready, I'll request review from you.

[Copilot]

Pull request overview

This PR enhances JDBC metadata reading robustness by adding comprehensive fallback mechanisms for drivers that don't fully implement JDBC metadata methods (e.g., Apache Hive), and fixes MariaDB-specific type mapping issues for BIGINT and unsigned integer types.

Key Changes:

• Added graceful fallbacks in getTableColumnsMetadata() for all ResultSetMetaData methods that may throw SQLFeatureNotSupportedException
• Fixed MariaDB type mappings to ensure BIGINT and unsigned integers always map to Long type, addressing driver inconsistencies
• Improved test robustness with proper resource cleanup using .use {} blocks and consistent table naming

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
dataframe-jdbc/src/main/kotlin/org/jetbrains/kotlinx/dataframe/io/db/DbType.kt	Added comprehensive exception handling fallbacks for JDBC metadata retrieval methods (catalog, schema, column names, types, nullability) and updated documentation to reflect fallback behavior
dataframe-jdbc/src/main/kotlin/org/jetbrains/kotlinx/dataframe/io/db/MariaDb.kt	Added explicit type mapping rules for BIGINT and unsigned integer types (INTEGER UNSIGNED, INT UNSIGNED) to consistently map to Long, fixing driver-reported type inconsistencies
dataframe-jdbc/src/test/kotlin/org/jetbrains/kotlinx/dataframe/io/local/mariadbTest.kt	Updated test assertion to expect ByteArray instead of Blob for TINYBLOB columns, aligning with corrected type mapping
dataframe-jdbc/src/test/kotlin/org/jetbrains/kotlinx/dataframe/io/commonTestScenarios.kt	Refactored test to use constant for table name, added proper cleanup with DROP TABLE IF EXISTS, and improved resource management with .use {} blocks

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.