Parquet Lens

Parquet Lens is a VS Code extension for viewing, querying, editing, and exporting Parquet files directly inside VS Code.

It is designed for large local Parquet files, SQL-driven inspection, and practical data-cleaning workflows where you need to locate rows, inspect long values, and safely persist edits.

Highlights

• Open .parquet and .parq files in a custom VS Code editor.
• Query files with DuckDB SQL.
• Default preview limit is enabled at 100 rows; clear the Limit checkbox to return all rows.
• Show total result rows and column count for the active query.
• Show schema in a collapsed panel by default.
• Edit cells from editable query results and save changes back to the Parquet file.
• Export the current query result as a standalone Parquet file.
• Show a collapsible row number column with 0-based and 1-based display modes.
• Truncate long values in the grid while showing their full character length.
• Mark NULL, empty strings, and whitespace-only strings explicitly with muted italic styling.
• Use an Excel-like value editor above the grid for previewing and editing the selected cell.
• Run queries quickly with Cmd+Enter on macOS or Ctrl+Enter on Windows/Linux.
• Show clear running feedback on query execution, with a stop action that ignores a pending result.
• Reset query and view state back to the default preview without discarding unsaved edits.
• Copy and paste the selected cell with Cmd+C/Cmd+V on macOS or Ctrl+C/Ctrl+V on Windows/Linux.
• Double-click a cell to focus the full-value editor for immediate editing.
• Preserve grid scroll position when selecting cells in large result sets.
• Drag-select row numbers or column headers, then right-click to delete selected rows or columns.
• Right-click row numbers or column headers to insert rows above/below or columns left/right; column insertion asks for the new name and then shows a type dropdown with VARCHAR first.
• Right-click an empty grid area to create a row or column when the current result has no rows or columns.
• Generate SQL from natural language with OpenAI-compatible /chat/completions APIs.

Install

Install from a VSIX file

Download the latest .vsix from the GitHub Releases page, then install it with:

code --install-extension parquet-lens-0.1.6.vsix --force

Reload VS Code after installation:

1. Open the Command Palette.
2. Run Developer: Reload Window.

Build and install locally

npm install
npm test
npm run package
code --install-extension parquet-lens-0.1.6.vsix --force

Usage

1. Open a .parquet or .parq file in VS Code.
2. Use SQL mode to query the table named data.
3. Keep Limit enabled for fast previews, or clear it to return the full result.
4. Expand Schema when you need column names and types.
5. Select a cell to preview its full value in the editor above the grid.
6. Edit cells in editable query results and save the editor to rewrite the Parquet file.
7. Use Export to save the current query result as a separate Parquet file.
8. Use Cmd+Enter or Ctrl+Enter in the SQL/NL input to run the query.
9. Left-click the row number header to collapse or expand row numbers; right-click it to switch between 0-based and 1-based numbering.
10. Use Reset to return to the default SQL preview, default limit, row numbering, and cleared selection. Reset does not discard unsaved data edits.
11. Select a cell and use Cmd+C/Ctrl+C or Cmd+V/Ctrl+V to copy or paste its full value. Double-click a cell to start editing in the full-value editor.
12. Drag across row numbers or column headers to select a range, then right-click the selection to delete it.
13. Right-click a row number to insert a row above or below; right-click a column header to insert a column left or right, then enter the new column name and choose its type from the dropdown.

Editable queries include simple single-table SELECT queries against data, including WHERE, ORDER BY, and LIMIT. Aggregations, DISTINCT, joins, unions, grouped queries, and expression columns are read-only to avoid unsafe writes.

Parquet Lens uses an internal row id to support reliable editing, but that internal field is hidden from the grid and removed from exported query results.

NL2SQL

Switch to NL mode to generate SQL from natural language. Configure the OpenAI-compatible API in the collapsed NL2SQL configuration panel or in VS Code settings:

• parquetLens.nl2sql.baseUrl
• parquetLens.nl2sql.apiKey
• parquetLens.nl2sql.model
• parquetLens.nl2sql.promptTemplate
• parquetLens.nl2sql.timeoutMs
• parquetLens.nl2sql.headers

The prompt template must include {{nl}}. It may also include {{schema}}.

When NL2SQL produces SQL but that SQL fails validation or execution, Parquet Lens switches back to SQL mode and leaves the generated SQL in the input so you can inspect and fix it.

Development

npm install
npm test
npm run package

The extension uses DuckDB for Parquet reading, SQL execution, schema inspection, result export, and Parquet rewrites on save.

License

MIT