--- title: "15: Viewing the schema | SurrealDB University" description: "Follow along with interactive SurrealDB lessons featuring hands-on exercises, code examples, and step-by-step instructions." url: https://surrealdb.com/learn/tour/page-15 --- ![Course content preview](https://surrealdb.com/assets/static/town.D95IYf2V.avif) [Back to Courses](https://surrealdb.com/learn) Course chapters [Welcome to the Tour of SurrealDB!](https://surrealdb.com/learn/tour) [1: Connecting to a database](https://surrealdb.com/learn/tour/page-01) [2: Creating records](https://surrealdb.com/learn/tour/page-02) [3: Using the ONLY keyword](https://surrealdb.com/learn/tour/page-03) [4: Non-ASCII record IDs](https://surrealdb.com/learn/tour/page-04) [5: Parentheses, indexing, and accessing fields](https://surrealdb.com/learn/tour/page-05) [6: Deleting records](https://surrealdb.com/learn/tour/page-06) [7: Field order in objects](https://surrealdb.com/learn/tour/page-07) [8: Tips when selecting records](https://surrealdb.com/learn/tour/page-08) [9: Casting and aliases](https://surrealdb.com/learn/tour/page-09) [10: Affixes](https://surrealdb.com/learn/tour/page-10) [11: Updating records](https://surrealdb.com/learn/tour/page-11) [12: Linking records](https://surrealdb.com/learn/tour/page-12) [13: Viewing the database as a whole](https://surrealdb.com/learn/tour/page-13) [14: Schemafull and schemaless](https://surrealdb.com/learn/tour/page-14) [15: Viewing the schema](https://surrealdb.com/learn/tour/page-15) [16: Literal types and assertions](https://surrealdb.com/learn/tour/page-16) [17: INSERT and using JSON](https://surrealdb.com/learn/tour/page-17) [18: FOR loops](https://surrealdb.com/learn/tour/page-18) [19: Basic graph relations](https://surrealdb.com/learn/tour/page-19) [20: Creating graph edges](https://surrealdb.com/learn/tour/page-20) [21: Querying graph relations](https://surrealdb.com/learn/tour/page-21) [22: Graph relations at greater depth](https://surrealdb.com/learn/tour/page-22) [23: Adding and improving data](https://surrealdb.com/learn/tour/page-23) [24: Defining events](https://surrealdb.com/learn/tour/page-24) [25: Defining indexes](https://surrealdb.com/learn/tour/page-25) [26: Improving the schema](https://surrealdb.com/learn/tour/page-26) [27: Visualising graph paths](https://surrealdb.com/learn/tour/page-27) [28: Recursive queries: setup](https://surrealdb.com/learn/tour/page-28) [29: Recursive queries](https://surrealdb.com/learn/tour/page-29) [30: More on recursive queries](https://surrealdb.com/learn/tour/page-30) [31: AI vector search](https://surrealdb.com/learn/tour/page-31) [Done the tour!](https://surrealdb.com/learn/tour/page-32) # 15: Viewing the schema Another advantage to having a schema is that the [Designer view](https://surrealdb.com/docs/surrealist/concepts/designing-the-database-schema) inside SurrealDB Studio can use it to show a graphical overview of the types used in the database. Without a schema, it isn't able to show much of anything. At the moment, all that it knows is that the database has two tables. But it has no idea whether `name` will always be a string, or whether `libraries` will always be an array that holds `place` records. ![A database schema containing two table names, place and town, and nothing else](https://surrealdb.com/assets/static/schema1.BoEH1u2Z.avif) The whole table doesn't need to be made `SCHEMAFULL` though. Instead, `DEFINE FIELD` can be used to define just one field at a time. This lets the table stay flexible for the most part, except for certain fields that we want to behave in a certain way. Here is the [`DEFINE FIELD`](https://surrealdb.com/docs/reference/query-language/statements/define/field) statement we used for practice on the last page. ```surql /** [test] [[test.results]] value = "NONE" */ DEFINE FIELD population ON schemafull_town TYPE number; ``` Following this format, we can define five fields to ensure that the fields for the `place` and `town` records can only be of a certain type. ``` -- Statements for the 'place' tableDEFINE FIELD address ON place TYPE string;DEFINE FIELD name ON place TYPE string;-- Statements for the 'town' tableDEFINE FIELD name ON town TYPE string;DEFINE FIELD population ON town TYPE int;DEFINE FIELD libraries ON town TYPE option>>;INFO FOR TABLE place;INFO FOR TABLE town; ``` ![Surrealist Icon](https://surrealdb.com/assets/static/fdfe2c20f5941d5e.D0guSOhZ.webp) Run Query The `INFO FOR TABLE` statements are no longer empty, showing the definitions for each field. Response ```surql -------- Query -------- { events: {}, fields: { address: 'DEFINE FIELD address ON place TYPE string PERMISSIONS FULL', name: 'DEFINE FIELD name ON place TYPE string PERMISSIONS FULL' }, indexes: {}, lives: {}, tables: {} } -------- Query -------- { events: {}, fields: { libraries: 'DEFINE FIELD libraries ON town TYPE option>> PERMISSIONS FULL', "libraries.*": 'DEFINE FIELD libraries.* ON town TYPE record PERMISSIONS FULL', name: 'DEFINE FIELD name ON town TYPE string PERMISSIONS FULL', population: 'DEFINE FIELD population ON town TYPE int PERMISSIONS FULL' }, indexes: {}, lives: {}, tables: {} } ``` The type of the last `DEFINE FIELD` statement above is a bit long: `option>>`. That is because: - Records are always of type `record`, so places are `record` and towns are `record`. - The `libraries` field should be able to hold more than one record, which gives us `array>`. - Not all towns have libraries, so we don't want to return an error if a `town` doesn't have this field. By wrapping it in an `option`, the `libraries` field doesn't need to be set in order to create a `town`. Once these statements are executed, SurrealDB Studio will be able to make a much more informative graphical schema for us. ![A database schema containing the same town and place tables, but with their fields now indicated along with a record link between the two](https://surrealdb.com/assets/static/schema2.BPjoHVE2.avif) Previous 14: Schemafull and schemaless [Previous](https://surrealdb.com/learn/tour/page-14) Next lesson 16: Literal types and assertions [Next lesson](https://surrealdb.com/learn/tour/page-16) ```json {"@context":"https://schema.org","@type":"Course","name":"Welcome to the Tour of SurrealDB!","description":"Welcome to the Tour of SurrealDB!","url":"https://surrealdb.com/learn/tour","inLanguage":"en","isAccessibleForFree":true,"provider":{"@type":"Organization","name":"SurrealDB","url":"https://surrealdb.com"},"hasPart":[{"@type":"LearningResource","name":"Welcome to the Tour of SurrealDB!","url":"https://surrealdb.com/learn/tour"},{"@type":"LearningResource","name":"1: 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