Dataherald vs SQL Mocker

Dataherald is an open-source natural language-to-SQL engine that exposes an API for asking questions about relational data in plain English. Its stated uses include helping business users query warehouses, embedding data Q&A in SaaS products, and creating ChatGPT plug-ins for proprietary data. The project targets developers building natural-language interfaces or contributing to the engine. Self-hosting uses Docker, with MongoDB in a separate container for application data. Listed warehouse connections are PostgreSQL, BigQuery, Databricks, and Snowflake. Included SQL-generation approaches are LangChain SQL Agent, LangChain SQL Chain, LlamaIndex SQL Generator, and Dataherald SQL Agent. A context store can include business and database details, validated question-and-SQL examples, and table information; active learning from usage is also described. An evaluator assigns confidence scores to generated SQL. The modular architecture allows implementations to be changed through .env configuration. Startup requires an OpenAI API key, organization ID, and encryption key. Connection data is encrypted before Mongo storage. The repository uses Apache-2.0 licensing.

SQL Mocker is a web app that generates SQL from natural-language questions using a reviewed copy of database schema metadata. Users can provide schema details through a file, pasted metadata, manual setup, or results from an extraction script run in their own database. Its workspace can detect, review, edit, or add table relationships, including ones missing from the supplied metadata. Existing SQL can also be submitted for explanation, review, improvement, formatting, conversion, troubleshooting, or mapping columns and joins. SQL Mocker can generate dummy data from a schema to preview results and test query logic without production rows. Its homepage lists 17 supported database systems, including SQL Server, PostgreSQL, MySQL, Oracle, Snowflake, BigQuery, and MongoDB. It says it needs no database credentials for schema-based generation and does not connect to a live customer database. Generated SQL is presented for review and copying; users run it themselves in their own database tool. Saved projects sync to the user account and are cached in the browser, with backup files available from History. The free Explore plan includes 50 AI queries total and five saved projects; paid plans are marked as coming soon.