Struct elephantry::Connection

pub struct Connection { /* fields omitted */ }

A connection to a database.

Implementations

impl Connection

pub fn new(dsn: &str) -> Result<Self>

pub fn async(&self) -> Async<'_>

pub fn transaction(&self) -> Transaction<'_>

pub fn from_config(config: &Config) -> Result<Self>

Creates a new connection from Config.

pub fn model<'a, M>(&'a self) -> M where
    M: Model<'a>, 

pub fn execute(&self, query: &str) -> Result<Result>

Executes a simple text query, without parameter.

pub fn query<E: Entity>(
    &self,
    query: &str,
    params: &[&dyn ToSql]
) -> Result<Rows<E>>

Executes a simple query, can have parameters.

pub fn query_one<E: Entity>(
    &self,
    query: &str,
    params: &[&dyn ToSql]
) -> Result<E>

Likes query but peaks only the first result.

pub fn find_by_pk<'a, M>(
    &self,
    pk: &HashMap<&str, &dyn ToSql>
) -> Result<Option<M::Entity>> where
    M: Model<'a>, 

Return an entity upon its primary key. If no entities are found, None is returned.

pub fn find_all<'a, M>(&self, suffix: Option<&str>) -> Result<Rows<M::Entity>> where
    M: Model<'a>, 

Return all elements from a relation. If a suffix is given, it is append to the query. This is mainly useful for “order by” statements.

NOTE: suffix is inserted as is with NO ESCAPING. DO NOT use it to place “where” condition nor any untrusted params.

pub fn find_where<'a, M>(
    &self,
    clause: &str,
    params: &[&dyn ToSql],
    suffix: Option<&str>
) -> Result<Rows<M::Entity>> where
    M: Model<'a>, 

Perform a simple select on a given condition

NOTE: suffix is inserted as is with NO ESCAPING. DO NOT use it to place “where” condition nor any untrusted params.

pub fn paginate_find_where<'a, M>(
    &self,
    clause: &str,
    params: &[&dyn ToSql],
    max_per_page: usize,
    page: usize,
    suffix: Option<&str>
) -> Result<Pager<M::Entity>> where
    M: Model<'a>, 

Paginate a query.

This is done with limit/offset, read why it’s probably not a good idea to use it: https://use-the-index-luke.com/no-offset.

pub fn count_where<'a, M>(
    &self,
    clause: &str,
    params: &[&dyn ToSql]
) -> Result<usize> where
    M: Model<'a>, 

Return the number of records matching a condition.

pub fn exist_where<'a, M>(
    &self,
    clause: &str,
    params: &[&dyn ToSql]
) -> Result<bool> where
    M: Model<'a>, 

Check if rows matching the given condition do exist or not.

pub fn insert_one<'a, M>(&self, entity: &M::Entity) -> Result<M::Entity> where
    M: Model<'a>, 

Insert a new entity in the database.

Returns the entity with values from database (ie: default values).

pub fn upsert_one<'a, M>(
    &self,
    entity: &M::Entity,
    target: &str,
    action: &str
) -> Result<Option<M::Entity>> where
    M: Model<'a>, 

Try to insert a new entity in the database. On constraint violation error on target you can do an alternative action action.

See ON CONFLICT clause.

Returns the entity with values from database (ie: default values).

pub fn update_one<'a, M>(
    &self,
    pk: &HashMap<&str, &dyn ToSql>,
    entity: &M::Entity
) -> Result<Option<M::Entity>> where
    M: Model<'a>, 

Update the entity.

Returns the entity with values from database.

pub fn update_by_pk<'a, M>(
    &self,
    pk: &HashMap<&str, &dyn ToSql>,
    data: &HashMap<String, &dyn ToSql>
) -> Result<Option<M::Entity>> where
    M: Model<'a>, 

Update a record and fetch it with its new values. If no records match the given key, None is returned.

pub fn delete_one<'a, M>(&self, entity: &M::Entity) -> Result<Option<M::Entity>> where
    M: Model<'a>, 

Delete an entity from a table.

Returns the entity fetched from the deleted record.

pub fn delete_by_pk<'a, M>(
    &self,
    pk: &HashMap<&str, &dyn ToSql>
) -> Result<Option<M::Entity>> where
    M: Model<'a>, 

Delete a record from its primary key. The deleted entity is returned or None if not found.

pub fn delete_where<'a, M>(
    &self,
    clause: &str,
    params: &[&dyn ToSql]
) -> Result<Rows<M::Entity>> where
    M: Model<'a>, 

Delete records by a given condition. A collection of all deleted entries is returned.

pub fn has_broken(&self) -> Result<bool>

Determines if the connection is no longer usable.

pub fn notify(&self, channel: &str, data: Option<&str>) -> Result

Send a NOTIFY event to the database server. An optional data can be sent with the notification.

pub fn listen(&self, channel: &str) -> Result

Start to listen on the given channel.

Note: when listen is issued in a transaction it is unlisten when the transaction is committed or rollback.

pub fn unlisten(&self, channel: &str) -> Result

Stop to listen on the given channel.

pub fn notifies(&self) -> Result<Option<Notify>>

Check if a notification is pending. If so, the payload is returned. Otherwise, None is returned.

pub fn ping(&self) -> Result<()>

Reports the status of the server.

pub fn config(&self) -> Result<Config>

Retreives connection configuration.

Trait Implementations

impl Clone for Connection

fn clone(&self) -> Connection

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Connection

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.