DB Playground

A VS Code extension for describing database schemas, editing their structure and building queries from local files. It generates Markdown, SQL and MongoDB scripts. It does not connect to databases or run the generated code.

Installation

Requires VS Code 1.80 or later. To install a .vsix package, choose Extensions → … → Install from VSIX…. The interface is in English.

Input files

SQL import does not cover all SQL syntax. CSV and JSON schemas are inferred from data. JSON profiling examines the first 100,000 documents and the first 20 elements of each array; regular .json files have a 512 MiB size limit.

Usage

Right-click a supported file and choose DB Playground, or use the commands in the Command Palette.

Describe a database schema

Opens a Markdown description in an unsaved editor tab. Choose Save in the notification to write <name>-schema.md and <name>.schema.json to the model folder. <name> is the source filename without its extension.

The description includes tables or collections, their fields and available metadata. Foreign-key relations and nested document structures include Mermaid diagrams.

Schema designer (changes and queries)

• Edit tables or collections, fields, indexes and SQL foreign keys. Use the list or diagram view, or the tree view for nested fields.
• Choose PostgreSQL, MySQL/MariaDB, Oracle, SQL Server or MongoDB as the output database.
• Preview changes against the loaded schema, or select full CREATE to generate creation statements.
• In Queries, choose result fields, filters, sorting and a row limit. SQL queries support joins suggested from foreign keys; MongoDB generates find() queries without joins.

Changing the output database does not convert existing field types. Some changes require manual edits to the script. For MongoDB, full CREATE creates empty collections without indexes or validation rules.

The designer automatically saves edits and queries to <name>.db-playground.json beside the source. Reopening restores that state instead of rereading the source. To reload the source, close the designer and move the state file aside.

Compare schema with the tree version (impact report)

Compares the source file with <name>.schema.json in its workspace's model folder. Save that schema first using Describe a database schema or the designer's script export.

The report covers added, removed or renamed tables and columns, changed types and whether fields are required. It does not compare indexes, keys, defaults or relations. Suggested renames need confirmation. The stored schema is updated only after you choose Save.

Saving files

In the designer, Open as file saves schema scripts and updates <name>.schema.json. Saving again replaces the script with the same name. Query previews open as unsaved files.

Paths are relative to the workspace folder; <project> is its name. Empty settings use the defaults.

For sources outside the workspace, descriptions are saved beside the source; designer scripts use the first open workspace folder. With no folder open, scripts open as unsaved files.

Privacy and links

No telemetry or network requests. Generated descriptions may contain example values from your data.

Issues · Security policy · Changelog · MIT license