Struct reindeer::QueryBuilder

pub struct QueryBuilder<'a> { /* private fields */ }

QueryBuilder is a convenient way to build query to target several conditions without the need to immediately serialize/deserialize data from disk. For simplicity’s sake, ids are expressed as &[u8]. To get the key of an entity using this type, just use &entity.get_key().as_bytes().

Execute the query with get or get_single, providing the Db instance to run it on.

Implementations

impl<'a> QueryBuilder<'a>

pub fn new() -> QueryBuilder<'a>

Creates a new Query Builder.

pub fn with_ids(&mut self, ids: &mut Vec<&impl AsBytes>) -> &mut QueryBuilder<'a>

Specifies an array of ids to consider in this query. This can be used multiple times.

pub fn with_id(&mut self, id: &impl AsBytes) -> &mut QueryBuilder<'a>

Specifies an single id to consider in this query. This can be used multiple times to specify several ids.

pub fn with_parent(&mut self, id: &impl AsBytes) -> &mut QueryBuilder<'a>

Specifies that this entity is the child of a given parent. This implies that the queried store is marked as a child of another entity type.

pub fn with_named_relation_to<OT: Entity>( &mut self, id: &impl AsBytes, name: &'a str ) -> &mut QueryBuilder<'a>

Specifies that a named relation to another entity has to exist. This can be used multiple times to specify several conditions.

pub fn with_relation_to<OT: Entity>( &mut self, id: &impl AsBytes ) -> &mut QueryBuilder<'a>

Specifies that an unnamed relation to another entity has to exist. This can be used multiple times to specify several conditions.

pub fn get<T: Entity>(&self, db: &Db) -> Result<Vec<T>>

Executes the query and returns the result as a Vec of the chosen entity.

pub fn get_single<T: Entity>(&self, db: &Db) -> Result<Option<T>>

Executes the query and returns the first entity matching the query.