🦆 DuckDB for VS Code

An unofficial DuckDB extension for Visual Studio Code. Query CSV, Parquet, JSON, and Excel files directly. Connect to .duckdb, S3, Postgres, Google Sheets and more.

Query Parquet files directly

Live Preview

Database Explorer

Overview

This extension brings DuckDB directly into VS Code with a focus on creating a productive "DuckDB workspace". Write and execute SQL queries, view results with column statistics, explore database schemas, and manage multiple database connections.

How It Works

All queries execute using the DuckDB Node API embedded in VS Code. By default, queries run against an in-memory database that resets when VS Code closes. You can attach persistent .duckdb files or connect to remote sources like Postgres, S3, or Google Sheets.

Performance Note: When you execute a query, the extension creates a temporary table to enable sorting, filtering, and exporting. Results stream into the viewport via infinite scroll — only the visible rows are in the DOM. For large datasets, DuckDB will spill to disk automatically — see Memory & Performance settings if you run into limits.

Features

SQL Execution

Execute queries — Cmd+Enter (Mac) / Ctrl+Enter (Windows/Linux)
Run individual statements — CodeLens "Run" buttons above each SQL statement
SQL autocomplete — Table names, columns, functions, and keywords. Can be disabled in settings.
SQL formatting — Format Document and Format Selection support with configurable keyword casing, indentation style, and logical operator placement
Inline diagnostics — Success confirmations with execution time and error messages shown inline after each statement

File Integration

Auto-open data files — .parquet, .csv/.tsv, and .xlsx files open directly in the DuckDB data viewer with full pagination, sorting, filtering, and export. No more "binary file" errors for Parquet!
Excel support — .xlsx workbooks with multiple sheets show a sheet picker with column previews; click any sheet to explore it. The DuckDB excel extension is auto-installed on first use.
JSON/JSONL support — .json, .jsonl, and .ndjson available via right-click → Open With… → DuckDB Data Viewer
Configurable — Each file type can be toggled via duckdb.fileViewer.* settings
Right-click to query — Select files in Explorer → "DuckDB: Query File" to open a SQL editor with SELECT * FROM '{file}'
Summarize files — Quick data profiling with SUMMARIZE

Results Table

Virtualized infinite scroll — Handle millions of rows efficiently; only visible rows live in the DOM
Quick Column sorting — Click headers to sort ASC/DESC
Quick Column filtering — Filter by values, ranges, or patterns
Cell selection — Click, Shift+click for ranges, copy to clipboard
Cell expansion & editing — Double-click to view full values (JSON syntax highlighted), or edit and save back to the source file (parquet, csv, json, etc.)
Editable SQL — "View SQL" modals are now editors: tweak and press ⌘↵ to re-run
Export options — CSV, Parquet, JSON, JSONL, or open in new tab

Column Statistics

Top values — Most frequent values for string columns
Descriptive stats — Min, max, mean, percentiles, null counts
Distribution histograms — Visual distribution for numeric columns

Database Explorer

Manage databases — Create, attach, and switch between databases
Status bar selector — Quick database switching
Schema browser — Databases → Schemas → Tables/Views → Columns
Quick actions — Select Top Rows, DESCRIBE, SUMMARIZE, View Definition, Drop Table

Inline Peek Results

Peek results — CodeLens "Peek" button above each statement opens an inline preview without leaving the editor
Execute on demand — Peek runs the query automatically if no cached results exist
Live preview mode — Optionally auto-refreshes results as you type (off by default, enable with duckdb.peekResults.livePreview)

Important: Remote Data Sources & Live Preview

If your queries reference remote sources (HTTP URLs, S3, GCS, Azure), live preview can cause excessive network requests since it re-executes the query on every keystroke (debounced). This also applies to indirect remote access through views, attached remote databases, or table functions that wrap remote sources — cases the extension cannot always detect automatically.

Strongly recommended: Install the cache_httpfs community extension to cache HTTP responses locally:
INSTALL cache_httpfs FROM community;
LOAD cache_httpfs;
Or add it to your workspace auto-load setting:
{ "duckdb.extensions.autoLoad": ["cache_httpfs"] }
The extension will prompt you to install cache_httpfs if it detects remote URLs in your SQL, but it cannot detect all cases (e.g., views over remote tables, attached remote databases). If you work with remote data, enable cache_httpfs proactively.

Extensions

Managed extensions — View, install, load, and configure extensions
Auto-load on startup — Configured extensions install and load automatically
Context-aware actions — Right-click to load, add/remove from auto-load

Query History

Automatic tracking — All queries saved with metadata
Re-run queries — Click to execute again
Open in editor — Edit and modify past queries
Optional persistence — Save to .vscode/duckdb-history.db

Settings

Configure in .vscode/settings.json or VS Code Settings UI:

Database Configuration

`duckdb.databases`

Databases to auto-attach on startup.

{
  "duckdb.databases": [
    {
      "alias": "analytics",
      "type": "file",
      "path": "./data/analytics.duckdb",
      "readOnly": false,
      "attached": true
    },
    {
      "alias": "s3_data",
      "type": "file",
      "path": "s3://bucket/path/to/data.duckdb",
      "readOnly": true,
      "attached": true
    },
    {
      "alias": "postgres_mirror",
      "type": "manual",
      "sql": "ATTACH 'postgres://user:pass@host/db' AS postgres_mirror (TYPE postgres, READ_ONLY)"
    }
  ]
}

Property	Type	Description
`alias`	string	Database name to use in queries
`type`	`"memory"` \| `"file"` \| `"manual"`	Database type
`path`	string	Path to .duckdb file (for `file` type)
`readOnly`	boolean	Open in read-only mode (default: `false`)
`attached`	boolean	Auto-attach on startup (default: `true`)
`sql`	string	Raw ATTACH statement (for `manual` type)

`duckdb.defaultDatabase`

Database to USE after attaching (default: "memory").

`duckdb.extensions.autoLoad`

Extensions to automatically install and load on startup.

{
  "duckdb.extensions.autoLoad": ["httpfs", "parquet", "json", "postgres"]
}

Inline Preview

`duckdb.peekResults.livePreview`

Enable live preview mode (default: false). When enabled, peeking a statement will auto-refresh results as you type. See the warning above about remote data sources.

`duckdb.peekResults.maxRows`

Maximum rows in the peek preview (default: 50, range: 5–500).

`duckdb.peekResults.debounceMs`

Debounce delay in ms for live preview (default: 600, range: 200–5000). Higher values reduce query frequency.

Data File Viewer

`duckdb.fileViewer.parquet`

Automatically open .parquet files with the DuckDB data viewer (default: true).

`duckdb.fileViewer.csv`

Automatically open .csv and .tsv files with the DuckDB data viewer (default: true).

`duckdb.fileViewer.json`

Automatically open .jsonl and .ndjson files with the DuckDB data viewer (default: false). Plain .json files are always available via Open With… but are never auto-opened to avoid disrupting config files.

`duckdb.fileViewer.excel`

Automatically open .xlsx files with the DuckDB data viewer (default: true). For workbooks with multiple sheets, a sheet picker is shown first. Requires the DuckDB excel extension, which is auto-installed on first use.

`duckdb.fileViewer.openMode`

Landing view when opening a data file (default: "schema").

Value	Description
`schema`	Show column metadata first — safe for any file size. Click "Query" to load rows on demand.
`data`	Jump straight into rows. The full result is materialized into a DuckDB temp table and rows stream into the viewport via infinite scroll.

Large files: In data mode the entire file is loaded into a temp table. DuckDB will spill to disk if it exceeds memoryLimit, but very large files can still be slow to open. If you regularly work with multi-GB files, keep the default schema mode and use the query buttons to sample or project specific columns.

`duckdb.fileViewer.openRowLimit`

Optional row cap when openMode is "data" (default: 0 = unlimited).

Set to a positive number (e.g. 100000) to apply a LIMIT to the auto-open query. Useful for sampling huge files without materializing the full result.

Results Display

`duckdb.resultsLocation`

Where to open query results (default: "active").

Value	Description
`beside`	Open in a new editor group beside the SQL file
`active`	Open in the same editor group as the SQL file

Tip: To open results below your SQL file instead of beside it, set VS Code's workbench.editor.openSideBySideDirection to "down".

`duckdb.pageSize`

Chunk size for virtualized scroll in the results table (default: 100, range: 10–10,000). Rows load on demand as you scroll; this controls how many are fetched per network round-trip to the extension host.

`duckdb.maxCopyRows`

Maximum rows for copy/export operations (default: 50000, range: 1,000–1,000,000).

Memory & Performance

The extension runs DuckDB inside VS Code's extension host process, which has a limited memory budget (~1.5 GB). To avoid crashing the extension when querying large files, DuckDB is configured to spill to disk when memory is exhausted.

`duckdb.memoryLimit`

Maximum memory DuckDB can use before spilling to disk (default: "1.5GB").

Warning: The VS Code extension host has a hard heap limit of approximately 1.5 GB. Setting this significantly higher (e.g. "3GB") will crash the entire extension with no error message — VS Code simply kills the process. If you experience silent crashes, check this setting first.

`duckdb.maxTempDirectorySize`

Maximum disk space for DuckDB temp/spill files (default: "15GB").

When DuckDB exceeds memoryLimit, it spills data to temporary files on disk. If those spill files exceed this limit, you'll see an error like:

DuckDB IO Error: failed to offload data block of size 256.0 KiB (5.8 GiB/5.8 GiB used).
This limit was set by the 'max_temp_directory_size' setting.

Increase this if you work with very large datasets:

{ "duckdb.maxTempDirectorySize": "50GB" }

`duckdb.tempDirectory`

Directory for DuckDB temp/spill files (default: OS temp directory, e.g. /tmp/duckdb-vscode on macOS/Linux).

Leave empty to use the OS temp directory, which is automatically cleaned up on reboot. Override this if the default location doesn't have enough disk space or isn't writable:

{ "duckdb.tempDirectory": "/path/to/large/disk/duckdb-temp" }

Database Explorer

`duckdb.explorer.defaultRowLimit`

Default row limit for Select Top Rows and Select Distinct Values in the database explorer (default: 1000, range: 1–100,000).

`duckdb.explorer.ignoredSchemas`

Schema names to hide from the database explorer tree (default: []). Schemas can also be hidden via right-click → "Hide Schema" in the explorer.

Autocomplete

`duckdb.autocomplete.enabled`

Enable SQL autocomplete suggestions (default: true).

SQL Formatting

`duckdb.format.keywordCase`

Keyword casing style (default: "upper").

Value	Description
`upper`	Uppercase keywords (SELECT, FROM, WHERE)
`lower`	Lowercase keywords (select, from, where)
`preserve`	Preserve original keyword casing

`duckdb.format.indentStyle`

Indentation style (default: "standard").

Value	Description
`standard`	Standard indentation
`tabularLeft`	Tabular style, keywords left-aligned
`tabularRight`	Tabular style, keywords right-aligned

`duckdb.format.logicalOperatorNewline`

Where to place logical operators relative to newlines (default: "before").

Value	Description
`before`	Place AND/OR before the newline
`after`	Place AND/OR after the newline

Query History

`duckdb.history.persist`

Save query history to .vscode/duckdb-history.db (default: false).

`duckdb.history.maxEntries`

Maximum history entries to keep (default: 1000).

Commands

Command	Keybinding	Description
DuckDB: Execute Query	`Cmd+Enter` / `Ctrl+Enter`	Run all SQL in active editor
DuckDB: Run Statement	—	Run a single statement (via CodeLens)
DuckDB: Run at Cursor	`Cmd+Shift+Enter` / `Ctrl+Shift+Enter`	Run the statement under the cursor
DuckDB: Select Database	—	Switch active database
DuckDB: Manage Extensions	—	Install/remove extensions
DuckDB: Query File	—	Query a data file (right-click)
DuckDB: Summarize File	—	Profile a data file
DuckDB: Copy Query	—	Copy SELECT statement for file
Go to Source File	—	Navigate from results to source SQL

Requirements

VS Code 1.85.0 or later
macOS, Linux, or Windows

License

MIT

Not affiliated with DuckDB Labs. DuckDB is a trademark of DuckDB Labs.

DuckDB

Charlie Jonas

🦆 DuckDB for VS Code

Overview

How It Works

Features

SQL Execution

File Integration

Results Table

Column Statistics

Database Explorer

Inline Peek Results

Extensions

Query History

Settings

Database Configuration

duckdb.databases

duckdb.defaultDatabase

duckdb.extensions.autoLoad

Inline Preview

duckdb.peekResults.livePreview

duckdb.peekResults.maxRows

duckdb.peekResults.debounceMs

Data File Viewer

duckdb.fileViewer.parquet

duckdb.fileViewer.csv

duckdb.fileViewer.json

duckdb.fileViewer.excel

duckdb.fileViewer.openMode

duckdb.fileViewer.openRowLimit

Results Display

duckdb.resultsLocation

duckdb.pageSize

duckdb.maxCopyRows

Memory & Performance

duckdb.memoryLimit

duckdb.maxTempDirectorySize

duckdb.tempDirectory

Database Explorer

duckdb.explorer.defaultRowLimit

duckdb.explorer.ignoredSchemas

Autocomplete

duckdb.autocomplete.enabled

SQL Formatting

duckdb.format.keywordCase

duckdb.format.indentStyle

duckdb.format.logicalOperatorNewline

Query History

duckdb.history.persist

duckdb.history.maxEntries

Commands

Requirements

License

`duckdb.databases`

`duckdb.defaultDatabase`

`duckdb.extensions.autoLoad`

`duckdb.peekResults.livePreview`

`duckdb.peekResults.maxRows`

`duckdb.peekResults.debounceMs`

`duckdb.fileViewer.parquet`

`duckdb.fileViewer.csv`

`duckdb.fileViewer.json`

`duckdb.fileViewer.excel`

`duckdb.fileViewer.openMode`

`duckdb.fileViewer.openRowLimit`

`duckdb.resultsLocation`

`duckdb.pageSize`

`duckdb.maxCopyRows`

`duckdb.memoryLimit`

`duckdb.maxTempDirectorySize`

`duckdb.tempDirectory`

`duckdb.explorer.defaultRowLimit`

`duckdb.explorer.ignoredSchemas`

`duckdb.autocomplete.enabled`

`duckdb.format.keywordCase`

`duckdb.format.indentStyle`

`duckdb.format.logicalOperatorNewline`

`duckdb.history.persist`

`duckdb.history.maxEntries`