Schema objects

In this guide, you’ll see how to use driver API methods and stateful objects to programmatically manipulate types and rules in a database schema using one of the TypeDB drivers. This page assumes you’ve already followed instructions from the Define query page.

Understanding schema objects

Schema objects represent types and rules in the schema of a TypeDB database. Driver APIs provide a set of methods to programmatically manipulate these objects.

Type objects

A type object has many useful methods to traverse the type hierarchy, find related types, and manipulate types definitions/properties. To manipulate a type with driver API methods, you need to get a stateful object that represents the type in the database.

Get type objects

To get a type object from a TypeDB database, you can use a TypeQL Get query or one of the driver API methods.

Get a type object by its label

Use type’s label to retrieve the type object. For example, to get a stateful object of the user entity type, use:

Example

let user_type = tx.concept().get_entity_type("user".to_owned()).resolve()?.unwrap();

rust

For more information, see the ConceptManager class methods.

Example

user_type = tx.concepts.get_entity_type("user").resolve()

python

For more information, see the ConceptManager class methods.

Example

let userType = await tx.concepts.getEntityType("user");

For more information, see the ConceptManager class methods.

Example

EntityType userType = tx.concepts().getEntityType("user").resolve();

java

For more information, see the ConceptManager class methods.

Example

IEntityType userType = tx.Concepts.GetEntityType("user").Resolve()!;

csharp

For more information, see the IConceptManager class methods.

Example

std::unique_ptr<TypeDB::EntityType> userType = tx.concepts.getEntityType("user").get();

cpp

For more information, see the ConceptManager class methods.

Example

Concept* userType = concept_promise_resolve(concepts_get_entity_type(tx, "user"));

For more information, see the Concept struct functions.

Query for types

Send a Get query with a pattern to retrieve types and process the response to get type objects. For example, to get all entity types, send the following Get query:

Example of a Get query for entity types

match
$x sub entity;
get $x;

typeql

Create type objects

To add a new type into the schema of a database, use a TypeQL Define query or one of the put type methods. For example, to add an entity type with the label admin by using put type method, use the following code:

Example

admin_type = tx.concepts.put_entity_type("admin").resolve()

rust

For more information, see the ConceptManager class methods.

Example

admin_type = tx.concepts.put_entity_type("admin").resolve()

python

For more information, see the ConceptManager class methods.

Example

let adminType = await tx.concepts.putEntityType("admin");

For more information, see the ConceptManager class methods.

Example

EntityType adminType = tx.concepts().putEntityType("admin").resolve();

java

For more information, see the ConceptManager class methods.

Example

IEntityType adminType = tx.Concepts.PutEntityType("admin").Resolve()!;

csharp

For more information, see the IConceptManager class methods.

Example

std::unique_ptr<TypeDB::EntityType> adminType = tx.concepts.putEntityType("admin").get();

cpp

For more information, see the ConceptManager class methods.

Example

Concept* adminType = concept_promise_resolve(concepts_put_entity_type(tx, "admin"));

For more information, see the Concept struct functions.

Type manipulation

A stateful type object has many useful methods to manipulate the type or traverse the type hierarchy of a schema:

get/set label,
get/set supertype,
get subtypes,
get ownerships,
get roles played,
etc.

For example, see how to change a supertype for the admin type we added previously:

Example

drop(admin_type.set_supertype(&tx, user_type.clone()).resolve());

rust

For more information on methods, available for manipulating Type objects, see the Schema class methods.

Example

admin_type.set_supertype(tx, user_type)

python

For more information on methods, available for manipulating Type objects, see the Schema class methods.

Example

await adminType.setSupertype(tx, userType);

For more information on methods, available for manipulating Type objects, see the Schema class methods.

Example

adminType.setSupertype(tx, userType).resolve();

java

For more information on methods, available for manipulating Type objects, see the Schema class methods.

Example

adminType.SetSupertype(tx, userType);

csharp

For more information on methods, available for manipulating Type objects, see the Schema class methods.

Example

adminType.get()->setSupertype(tx, userType.get()).wait();

cpp

For more information on methods, available for manipulating Type objects, see the Schema class methods.

Example

entity_type_set_supertype(tx, adminType, userType);

For more information on methods, available for manipulating Type objects, see the Schema section functions.

Full example

See below a more comprehensive example of type objects manipulation. In this example we retrieve the user type object, create the admin type and set user as a supertype for admin. Then we retrieve all subtypes of the entity root types (effectively all entity types) and print their labels.

let databases = DatabaseManager::new(driver);
let db = databases.get(DB_NAME)?;
{
    let session = Session::new(db, SessionType::Schema)?;
    {
        let tx = session.transaction(TransactionType::Write)?;
        let user_type = tx.concept().get_entity_type("user".to_owned()).resolve()?.ok_or("No root entity")?;
        let mut admin_type = tx.concept().put_entity_type("admin".to_owned()).resolve()?;
        drop(admin_type.set_supertype(&tx, user_type).resolve());
        let entities = tx
            .concept()
            .get_entity_type("entity".to_owned())
            .resolve()?
            .ok_or("No root entity")?
            .get_subtypes(&tx, Transitivity::Transitive)?;
        for subtype in entities {
            println!("{}", subtype?.label);
        }
        let _ = tx.commit().resolve();
    }
}

rust

with driver.session(DB_NAME, SessionType.SCHEMA) as session:
    with session.transaction(TransactionType.WRITE) as tx:
        user_type = tx.concepts.get_entity_type("user").resolve()
        admin_type = tx.concepts.put_entity_type("admin").resolve()
        admin_type.set_supertype(tx, user_type)
        root_entity = tx.concepts.get_root_entity_type()
        subtypes = list(root_entity.get_subtypes(tx, Transitivity.TRANSITIVE))
        for subtype in subtypes:
            print(subtype.get_label().name)
        tx.commit()

python

try {
    session = await driver.session(DB_NAME, SessionType.SCHEMA);
    try {
        tx = await session.transaction(TransactionType.WRITE);
        let user = await tx.concepts.getEntityType("user");
        let admin = await tx.concepts.putEntityType("admin");
        await admin.setSupertype(tx, user);
        let rootEntity = await tx.concepts.getRootEntityType();
        let subtypes = await rootEntity.getSubtypes(tx, Concept.Transitivity.TRANSITIVE);
        await subtypes.forEach(subtype => console.log(subtype.label.toString()));
        await tx.commit();
    }
    finally {if (tx.isOpen()) {await tx.close()};}
}
finally {await session?.close();}

try (TypeDBSession session = driver.session(DB_NAME, TypeDBSession.Type.SCHEMA)) {
    try (TypeDBTransaction tx = session.transaction(TypeDBTransaction.Type.WRITE)) {
        EntityType userType = tx.concepts().getEntityType("user").resolve();
        EntityType adminType = tx.concepts().putEntityType("admin").resolve();
        adminType.setSupertype(tx, userType).resolve();
        EntityType root_entity = tx.concepts().getRootEntityType();
        root_entity.getSubtypes(tx, Concept.Transitivity.TRANSITIVE).forEach(result -> System.out.println(result.getLabel().name()));
        tx.commit();
    }
}

java

using (ITypeDBSession session = driver.Session(DB_NAME, SessionType.Schema)) {
    using (ITypeDBTransaction tx = session.Transaction(TransactionType.Write)) {
        IEntityType userType = tx.Concepts.GetEntityType("user").Resolve()!;
        IEntityType adminType = tx.Concepts.PutEntityType("admin").Resolve()!;
        adminType.SetSupertype(tx, userType);
        IEnumerable<IType> entities = tx.Concepts.RootEntityType.GetSubtypes(tx, IConcept.Transitivity.Transitive);
        foreach (IType entity in entities) {
            Console.WriteLine(entity.Label);
        }
        tx.Commit();
    }
}

csharp

TypeDB::Options options;
TypeDB::Session session = driver.session(DB_NAME, TypeDB::SessionType::SCHEMA, options);
{
    TypeDB::Transaction tx = session.transaction(TypeDB::TransactionType::WRITE, options);
    std::unique_ptr<TypeDB::EntityType> userType = tx.concepts.getEntityType("user").get();
    std::unique_ptr<TypeDB::EntityType> adminType = tx.concepts.putEntityType("admin").get();
    adminType.get()->setSupertype(tx, userType.get()).wait();
    TypeDB::ConceptIterable<TypeDB::EntityType> entities = tx.concepts.getRootEntityType().get()->getSubtypes(tx, TypeDB::Transitivity::TRANSITIVE);
    for (std::unique_ptr<TypeDB::EntityType>& entity : entities) {
        std::cout << entity.get()->getLabel() << std::endl;
    }
    tx.commit();
}

cpp

Options* opts = options_new();
session = session_new(databaseManager, DB_NAME, Schema, opts);
tx = transaction_new(session, Write, opts);
if ((tx == NULL) || FAILED()) {
    handle_error("Transaction failed to start.");
    goto cleanup;
}
Concept* userType = concept_promise_resolve(concepts_get_entity_type(tx, "user"));
Concept* adminType = concept_promise_resolve(concepts_put_entity_type(tx, "admin"));
entity_type_set_supertype(tx, adminType, userType);
ConceptIterator* entities = entity_type_get_subtypes(tx, concepts_get_root_entity_type(), Transitive);
Concept* entity;
while ((entity = concept_iterator_next(entities)) != NULL) {
    printf("%s\n", thing_type_get_label(entity));
}
void_promise_resolve(transaction_commit(tx));
if (FAILED()) {
    handle_error("Transaction commit failed.");
    goto cleanup;
}
session_close(session);

For an additional example of programmatic type manipulations, see the Schema editing page.

Rule objects

A rule object has label, when, and then properties and just a few methods.

To manipulate a rule with driver API methods, you need to get a stateful object that represents the rule in the database.

Get a rule

Rules can be defined with a TypeQL query (see Define query), but they can’t be retrieved with one. To get a rule object from a TypeDB database, you need to use the Logic class methods of a driver API.

Get a rule object by its label

Use rule’s label to retrieve the rule object. For example, to get a stateful object of the rule with the label Employee, use:

Example

let old_rule = tx.logic().get_rule("users".to_owned()).resolve()?.ok_or("Rule not found.")?;

rust

For more information, see the get_rule() method in driver API reference.

Example

old_rule = tx.logic.get_rule("users").resolve()

python

For more information, see the get_rule() method in driver API reference.

Example

let oldRule = (await tx.logic.getRule("users")).label;

For more information, see the get_rule() method in driver API reference.

Example

Rule oldRule = tx.logic().getRule("users").resolve();

java

For more information, see the getRule() method in driver API reference.

Example

IRule oldRule = tx.Logic.GetRule("users").Resolve()!;

csharp

For more information, see the GetRule() method in driver API reference.

Example

TypeDB::Rule oldRule = tx.logic.getRule("users").get().value();

cpp

For more information, see the getRule() method in driver API reference.

Example

Rule* oldRule = rule_promise_resolve(logic_manager_get_rule(tx, "users"));

For more information, see the get_rule() function in driver API reference.

Get all rules

Use get rules method to retrieve all rules in a schema:

Example

let rules = tx.logic().get_rules()?;
for rule in rules {
    println!("{}", rule.clone()?.label);
    println!("{}", rule.clone()?.when.to_string());
    println!("{}", rule.clone()?.then.to_string());
}

rust

For more information, see the get_rules() method in driver API reference.

Example

rules = tx.logic.get_rules()
for rule in rules:
    print(rule.label)
    print(rule.when)
    print(rule.then)

python

For more information, see the get_rules() method in driver API reference.

Example

let rules = await tx.logic.getRules();
for await (const rule of rules) {
    console.log(rule.label);
    console.log(rule.when);
    console.log(rule.then);
}

For more information, see the getRules() method in driver API reference.

Example

tx.logic().getRules().forEach(result -> {
    System.out.println(result.getLabel());
    System.out.println(result.getWhen().toString());
    System.out.println(result.getThen().toString());
});

java

For more information, see the getRules() method in driver API reference.

Example

IEnumerable<IRule> rules = tx.Logic.GetRules();
foreach (IRule rule in rules) {
    Console.WriteLine(rule.Label);
    Console.WriteLine(rule.When);
    Console.WriteLine(rule.Then);
}

csharp

For more information, see the GetRules() method in driver API reference.

Example

TypeDB::RuleIterable rules = tx.logic.getRules();
for (TypeDB::Rule& rule : rules) {
    std::cout << rule.label() << std::endl;
    std::cout << rule.when() << std::endl;
    std::cout << rule.then() << std::endl;
}

cpp

For more information, see the getRules() method in driver API reference.

Example

RuleIterator* rules = logic_manager_get_rules(tx);
Rule* rule;
while ((rule = rule_iterator_next(rules)) != NULL) {
    printf("%s\n%s\n%s\n", rule_get_label(rule), rule_get_when(rule), rule_get_then(rule));
}

For more information, see the get_rules() function in driver API reference.

Add a rule

Use the following methods to add a rule to the schema of a database:

Example

let condition = typeql::parse_pattern("{$u isa user, has email $e; $e contains '@typedb.com';}")?
    .into_conjunction();
let conclusion = typeql::parse_pattern("$u has name 'Employee'")?.into_statement();
let mut new_rule = tx.logic().put_rule("Employee".to_string(), condition, conclusion).resolve()?;

rust

For more information, see the put_rule() method in driver API reference.

Example

new_rule = tx.logic.put_rule("Employee",
                             "{$u isa user, has email $e; $e contains '@typedb.com';}",
                             "$u has name 'Employee'").resolve()

python

For more information, see the put_rule() method in driver API reference.

Example

let newRule = await tx.logic.putRule("Employee","{$u isa user, has email $e; $e contains '@typedb.com';}","$u has name 'Employee'");

For more information, see the putRule() method in driver API reference.

Example

Pattern condition = TypeQL.parsePattern("{$u isa user, has email $e; $e contains '@typedb.com';}");
Pattern conclusion = TypeQL.parsePattern("$u has name 'Employee'");
Rule newRule = tx.logic().putRule("Employee", condition, conclusion).resolve();

java

For more information, see the putRule() method in driver API reference.

Example

IRule newRule = tx.Logic.PutRule("Employee", "{$u isa user, has email $e; $e contains '@typedb.com';}","$u has name 'Employee'").Resolve()!;

csharp

For more information, see the PutRule() method in driver API reference.

Example

TypeDB::Rule newRule = tx.logic.putRule("Employee", "{$u isa user, has email $e; $e contains '@typedb.com';}","$u has name 'Employee'").get();

cpp

For more information, see the putRule() method in driver API reference.

Example

Rule* newRule = rule_promise_resolve(logic_manager_put_rule(tx, "Employee", "{$u isa user, has email $e; $e contains '@typedb.com';}", "$u has name 'Employee'"));

For more information, see the put_rule() function in driver API reference.

Rule manipulation

A stateful rule object has just a few methods: get/set label, delete, and is_deleted.

Example

let _ = new_rule.delete(&tx).resolve();

rust