--- title: "Functions | SurrealDB" description: "Compute inside the database. Define SurrealQL functions, run JavaScript, and load sandboxed WebAssembly extensions, all in the same transaction as your data." url: https://surrealdb.com/surrealdb/functions --- FUNCTIONS # Functions inside the database Push logic to where the data lives. Define reusable SurrealQL functions, drop into JavaScript when you need it, and load sandboxed WebAssembly extensions in Rust - all executing in the same ACID transaction as your query, with no service to call and no data to ship over the wire. [Read the docs](https://surrealdb.com/docs/reference/query-language/statements/define/function) [Start free with SurrealDB](https://studio.surrealdb.com/current/instances/deploy) 1. ![Babcock](https://surrealdb.com/assets/static/babcock.lo4rnVg1.svg) 2. ![ING](https://surrealdb.com/assets/static/ing.X3I6S3_V.svg) 3. ![British Airways](https://surrealdb.com/assets/static/british-airways.KEsZiwV-.svg) 4. ![Nvidia](https://surrealdb.com/assets/static/nvidia.DaIEuMil.svg) 5. ![Apple](https://surrealdb.com/assets/static/apple.D5pq4flY.svg) 6. ![SpaceX](https://surrealdb.com/assets/static/spacex.CQJEk-IL.svg) 7. ![Samsung](https://surrealdb.com/assets/static/samsung.CH-vQgnb.svg) 8. ![adidas](https://surrealdb.com/assets/static/adidas.DdTC5qhk.svg) 9. ![Tencent](https://surrealdb.com/assets/static/tencent.paQmLxyy.svg) 10. ![Alibaba](https://surrealdb.com/assets/static/alibaba.B16idgfM.svg) 11. ![PolyAI](https://surrealdb.com/assets/static/poly-ai.c3w_fAg6.svg) 12. ![Later](https://surrealdb.com/assets/static/later.Ds736jFO.svg) 13. ![Verizon](https://surrealdb.com/assets/static/verizon.BI7CajdX.svg) 14. ![Liberty Mutual](https://surrealdb.com/assets/static/liberty-mutual.B7qOU1pd.svg) 15. ![Walmart](https://surrealdb.com/assets/static/walmart.BjDg_Sr8.svg) 16. ![Carrier](https://surrealdb.com/assets/static/carrier.D21gC6NX.svg) 17. ![Saks Fifth Avenue](https://surrealdb.com/assets/static/saks-fifth-avenue.COIDpLSb.svg) 18. ![San Francisco Compute Company](https://surrealdb.com/assets/static/sfcc.B7jlImq4.svg) 19. ![Shield AI](https://surrealdb.com/assets/static/shield-ai.pINZ0KJr.svg) 20. ![Wix](https://surrealdb.com/assets/static/wix.DvHhmoBi.svg) 01 |IN-DATABASE LOGIC ## From one-liners to compiled extensions Custom functions, embedded JavaScript, and WebAssembly modules give you a ladder from a quick helper to native-speed compute, all callable directly from SurrealQL. CUSTOM FUNCTIONS ## Reusable logic, defined once DEFINE FUNCTION stores named, typed procedures in the database. Call them from any query the way you call built-ins. ``` DEFINE FUNCTION fn::get::person( $first: string, $last: string, $birthday: string) { LET $person = SELECT * FROM person WHERE first = $first AND last = $last AND birthday = $birthday; RETURN IF $person[0].id { $person[0] } ELSE { CREATE person SET first = $first, last = $last, birthday = $birthday };};LET $person = fn::get::person('Tobie', 'Morgan Hitchcock', '2007-06-22'); ``` WEBASSEMBLY EXTENSIONS ## Native-speed logic, sandboxed Write an extension in Rust, compile it to a WebAssembly module, and load it into a running database. Its functions become callable from SurrealQL, sandboxed and inside the transaction. ``` DEFINE MODULE mod::sentiment FROM f"modules:/sentiment.surli" UNSIGNED;UPDATE article SET sentiment = mod::sentiment::analyze(content), keywords = mod::sentiment::extract(content)WHERE created_at > time::now() - 1h; ``` ## A full compute surface, next to your data Built-in function families, custom procedures, scripting, and compiled extensions - every layer runs in the engine, in the transaction. ### [Custom functions](https://surrealdb.com/docs/reference/query-language/statements/define/function) Typed, reusable SurrealQL procedures stored in the database and callable from any query. Learn more ### [Built-in functions](https://surrealdb.com/surrealdb/features#functions-and-extensibility) Array, string, math, time, vector, geo, search, and more - hundreds of functions ready in the query language. Learn more ### [JavaScript scripting](https://surrealdb.com/surrealdb/features#functions-and-extensibility) Drop into embedded JavaScript with the current record as context when SurrealQL is not enough. Learn more ### [WebAssembly extensions](https://surrealdb.com/surrealdb/extensions) Write extensions in Rust, compile to WASM, and run them at near-native speed inside a sandbox. Learn more ### [AI-ready by design](https://surrealdb.com/surrealdb/extensions) Call models and inference next to the data and write results back in a single statement. Learn more ### [Hot-load, no downtime](https://surrealdb.com/surrealdb/extensions) Load and upgrade extension modules on a running instance without restarting the database. Learn more 02 |ONE ENGINE ## Move the compute to the data Pulling rows into an application server, transforming them, and writing them back costs a round trip and breaks atomicity. Running the logic in the database removes both problems. ### No round trips Logic executes beside the data, so there is no fetch-transform-write hop across the network for every operation. ### One transaction Functions and extensions participate in the same ACID transaction as the query that calls them - results commit together or not at all. ### One deployment No function-as-a-service to provision, secure, and scale separately. The compute ships with the database. ## Keep exploring ### [Extensions](https://surrealdb.com/surrealdb/extensions) The WebAssembly extension system in depth. Explore ### [Functions documentation](https://surrealdb.com/docs/reference/query-language/functions/database-functions) Every built-in family and how to define your own. Explore ### [All features](https://surrealdb.com/surrealdb/features#functions-and-extensibility) The complete functions and extensibility set. Explore GET STARTED ## Run your logic where your data lives Define functions, script in JavaScript, and load WebAssembly extensions - all inside SurrealDB. ![Samsung](https://surrealdb.com/assets/static/4c58b81e7b3c9466.C_Hv0eml.svg)![NVIDIA](https://surrealdb.com/assets/static/nvidia.DaIEuMil.svg)![Apple](https://surrealdb.com/assets/static/f7dc2519e0d212bc.Cn8MYAK7.svg)![Verizon](https://surrealdb.com/assets/static/18b99996c689000f.B5PQ-nI9.svg)![Tencent](https://surrealdb.com/assets/static/401d8346058682c8.DqM87mst.svg) SOC 2 Type 2 GDPR Cyber Essentials Plus ISO 27001 [Read the docs](https://surrealdb.com/docs/reference/query-language/statements/define/function) [Start free with SurrealDB](https://studio.surrealdb.com/current/instances/deploy) ```json {"@context":"https://schema.org","@type":"Organization","name":"SurrealDB","url":"https://surrealdb.com","logo":"https://surrealdb.com/assets/static/logo.BG7_TG2b.svg","description":"SurrealDB is the unified data layer for AI. 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