Enum sea_orm::DatabaseBackend

pub enum DatabaseBackend {
    MySql,
    Postgres,
    Sqlite,
}

The type of database backend for real world databases. This is enabled by feature flags as specified in the crate documentation

Variants

MySql

A MySQL backend

Postgres

A PostgreSQL backend

Sqlite

A SQLite backend

Implementations

impl DatabaseBackend

pub fn is_prefix_of(self, base_url: &str) -> bool

Check if the URI is the same as the specified database backend. Returns true if they match.

Examples found in repository

src/driver/mock.rs (line 57)

    pub fn accepts(string: &str) -> bool {
        #[cfg(feature = "sqlx-mysql")]
        if DbBackend::MySql.is_prefix_of(string) {
            return true;
        }
        #[cfg(feature = "sqlx-postgres")]
        if DbBackend::Postgres.is_prefix_of(string) {
            return true;
        }
        #[cfg(feature = "sqlx-sqlite")]
        if DbBackend::Sqlite.is_prefix_of(string) {
            return true;
        }
        false
    }

pub fn build<S>(&self, statement: &S) -> Statementwhere
    S: StatementBuilder,

Build an SQL Statement

Examples found in repository

src/executor/delete.rs (line 60)

    pub fn exec<C>(self, db: &C) -> impl Future<Output = Result<DeleteResult, DbErr>> + '_
    where
        C: ConnectionTrait,
    {
        let builder = db.get_database_backend();
        exec_delete(builder.build(&self.query), db)
    }

src/executor/update.rs (line 72)

    pub fn exec<C>(self, db: &C) -> impl Future<Output = Result<UpdateResult, DbErr>> + '_
    where
        C: ConnectionTrait,
    {
        let builder = db.get_database_backend();
        exec_update(builder.build(&self.query), db, self.check_record_exists)
    }
}

async fn exec_update_only<C>(query: UpdateStatement, db: &C) -> Result<UpdateResult, DbErr>
where
    C: ConnectionTrait,
{
    Updater::new(query).exec(db).await
}

async fn exec_update_and_return_updated<A, C>(
    mut query: UpdateStatement,
    model: A,
    db: &C,
) -> Result<<A::Entity as EntityTrait>::Model, DbErr>
where
    A: ActiveModelTrait,
    C: ConnectionTrait,
{
    match db.support_returning() {
        true => {
            let returning = Query::returning().exprs(
                <A::Entity as EntityTrait>::Column::iter()
                    .map(|c| cast_enum_as_text(Expr::col(c), &c)),
            );
            query.returning(returning);
            let db_backend = db.get_database_backend();
            let found: Option<<A::Entity as EntityTrait>::Model> =
                SelectorRaw::<SelectModel<<A::Entity as EntityTrait>::Model>>::from_statement(
                    db_backend.build(&query),
                )
                .one(db)
                .await?;
            // If we got `None` then we are updating a row that does not exist.
            match found {
                Some(model) => Ok(model),
                None => Err(DbErr::RecordNotFound(
                    "None of the database rows are affected".to_owned(),
                )),
            }
        }
        false => {
            // If we updating a row that does not exist then an error will be thrown here.
            Updater::new(query).check_record_exists().exec(db).await?;
            let primary_key_value = match model.get_primary_key_value() {
                Some(val) => FromValueTuple::from_value_tuple(val),
                None => return Err(DbErr::UpdateGetPrimaryKey),
            };
            let found = <A::Entity as EntityTrait>::find_by_id(primary_key_value)
                .one(db)
                .await?;
            // If we cannot select the updated row from db by the cached primary key
            match found {
                Some(model) => Ok(model),
                None => Err(DbErr::RecordNotFound(
                    "Failed to find updated item".to_owned(),
                )),
            }
        }
    }
}

src/executor/insert.rs (line 99)

    pub fn exec<'a, C>(self, db: &'a C) -> impl Future<Output = Result<InsertResult<A>, DbErr>> + '_
    where
        C: ConnectionTrait,
        A: 'a,
    {
        let builder = db.get_database_backend();
        exec_insert(self.primary_key, builder.build(&self.query), db)
    }

    /// Execute an insert operation
    pub fn exec_without_returning<'a, C>(
        self,
        db: &'a C,
    ) -> impl Future<Output = Result<u64, DbErr>> + '_
    where
        C: ConnectionTrait,
        A: 'a,
    {
        exec_insert_without_returning(self.query, db)
    }

    /// Execute an insert operation and return the inserted model (use `RETURNING` syntax if database supported)
    pub fn exec_with_returning<'a, C>(
        self,
        db: &'a C,
    ) -> impl Future<Output = Result<<A::Entity as EntityTrait>::Model, DbErr>> + '_
    where
        <A::Entity as EntityTrait>::Model: IntoActiveModel<A>,
        C: ConnectionTrait,
        A: 'a,
    {
        exec_insert_with_returning::<A, _>(self.primary_key, self.query, db)
    }
}

#[allow(unused_variables, unreachable_code)]
async fn exec_insert<A, C>(
    primary_key: Option<ValueTuple>,
    statement: Statement,
    db: &C,
) -> Result<InsertResult<A>, DbErr>
where
    C: ConnectionTrait,
    A: ActiveModelTrait,
{
    type PrimaryKey<A> = <<A as ActiveModelTrait>::Entity as EntityTrait>::PrimaryKey;
    type ValueTypeOf<A> = <PrimaryKey<A> as PrimaryKeyTrait>::ValueType;
    let last_insert_id_opt = match db.support_returning() {
        true => {
            let cols = PrimaryKey::<A>::iter()
                .map(|col| col.to_string())
                .collect::<Vec<_>>();
            let res = db.query_one(statement).await?.unwrap();
            res.try_get_many("", cols.as_ref()).ok()
        }
        false => {
            let last_insert_id = db.execute(statement).await?.last_insert_id();
            ValueTypeOf::<A>::try_from_u64(last_insert_id).ok()
        }
    };
    let last_insert_id = match primary_key {
        Some(value_tuple) => FromValueTuple::from_value_tuple(value_tuple),
        None => match last_insert_id_opt {
            Some(last_insert_id) => last_insert_id,
            None => return Err(DbErr::UnpackInsertId),
        },
    };
    Ok(InsertResult { last_insert_id })
}

async fn exec_insert_without_returning<C>(
    insert_statement: InsertStatement,
    db: &C,
) -> Result<u64, DbErr>
where
    C: ConnectionTrait,
{
    let db_backend = db.get_database_backend();
    let exec_result = db.execute(db_backend.build(&insert_statement)).await?;
    Ok(exec_result.rows_affected())
}

async fn exec_insert_with_returning<A, C>(
    primary_key: Option<ValueTuple>,
    mut insert_statement: InsertStatement,
    db: &C,
) -> Result<<A::Entity as EntityTrait>::Model, DbErr>
where
    <A::Entity as EntityTrait>::Model: IntoActiveModel<A>,
    C: ConnectionTrait,
    A: ActiveModelTrait,
{
    let db_backend = db.get_database_backend();
    let found = match db.support_returning() {
        true => {
            let returning = Query::returning().exprs(
                <A::Entity as EntityTrait>::Column::iter()
                    .map(|c| cast_enum_as_text(Expr::col(c), &c)),
            );
            insert_statement.returning(returning);
            SelectorRaw::<SelectModel<<A::Entity as EntityTrait>::Model>>::from_statement(
                db_backend.build(&insert_statement),
            )
            .one(db)
            .await?
        }
        false => {
            let insert_res =
                exec_insert::<A, _>(primary_key, db_backend.build(&insert_statement), db).await?;
            <A::Entity as EntityTrait>::find_by_id(insert_res.last_insert_id)
                .one(db)
                .await?
        }
    };
    match found {
        Some(model) => Ok(model),
        None => Err(DbErr::RecordNotFound(
            "Failed to find inserted item".to_owned(),
        )),
    }
}

src/executor/select.rs (line 426)

    fn into_selector_raw<C>(self, db: &C) -> SelectorRaw<S>
    where
        C: ConnectionTrait,
    {
        let builder = db.get_database_backend();
        let stmt = builder.build(&self.query);
        SelectorRaw {
            stmt,
            selector: self.selector,
        }
    }

src/executor/cursor.rs (line 148)

    pub async fn all<C>(&mut self, db: &C) -> Result<Vec<S::Item>, DbErr>
    where
        C: ConnectionTrait,
    {
        let stmt = db.get_database_backend().build(&self.query);
        let rows = db.query_all(stmt).await?;
        let mut buffer = Vec::with_capacity(rows.len());
        for row in rows.into_iter() {
            buffer.push(S::from_raw_query_result(row)?);
        }
        if self.last {
            buffer.reverse()
        }
        Ok(buffer)
    }

src/executor/paginator.rs (line 52)

    pub async fn fetch_page(&self, page: u64) -> Result<Vec<S::Item>, DbErr> {
        let query = self
            .query
            .clone()
            .limit(self.page_size)
            .offset(self.page_size * page)
            .to_owned();
        let builder = self.db.get_database_backend();
        let stmt = builder.build(&query);
        let rows = self.db.query_all(stmt).await?;
        let mut buffer = Vec::with_capacity(rows.len());
        for row in rows.into_iter() {
            // TODO: Error handling
            buffer.push(S::from_raw_query_result(row)?);
        }
        Ok(buffer)
    }

    /// Fetch the current page
    pub async fn fetch(&self) -> Result<Vec<S::Item>, DbErr> {
        self.fetch_page(self.page).await
    }

    /// Get the total number of items
    pub async fn num_items(&self) -> Result<u64, DbErr> {
        let builder = self.db.get_database_backend();
        let stmt = builder.build(
            SelectStatement::new()
                .expr(Expr::cust("COUNT(*) AS num_items"))
                .from_subquery(
                    self.query.clone().reset_limit().reset_offset().to_owned(),
                    Alias::new("sub_query"),
                ),
        );
        let result = match self.db.query_one(stmt).await? {
            Some(res) => res,
            None => return Ok(0),
        };
        let num_items = match builder {
            DbBackend::Postgres => result.try_get::<i64>("", "num_items")? as u64,
            _ => result.try_get::<i32>("", "num_items")? as u64,
        };
        Ok(num_items)
    }

pub fn get_query_builder(&self) -> Box<dyn QueryBuilder>

A helper for building SQL queries

Examples found in repository

src/query/traits.rs (line 20)

    fn build(&self, db_backend: DbBackend) -> Statement {
        let query_builder = db_backend.get_query_builder();
        Statement::from_string_values_tuple(
            db_backend,
            self.as_query().build_any(query_builder.as_ref()),
        )
    }

src/database/statement.rs (line 65)

    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match &self.values {
            Some(values) => {
                let string = inject_parameters(
                    &self.sql,
                    values.0.clone(),
                    self.db_backend.get_query_builder().as_ref(),
                );
                write!(f, "{}", &string)
            }
            None => {
                write!(f, "{}", &self.sql)
            }
        }
    }

pub fn support_returning(&self) -> bool

Check if the database supports RETURNING syntax on insert and update

Examples found in repository

src/database/connection.rs (line 27)

    fn support_returning(&self) -> bool {
        let db_backend = self.get_database_backend();
        db_backend.support_returning()
    }

Trait Implementations

impl Clone for DatabaseBackend

fn clone(&self) -> DatabaseBackend

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for DatabaseBackend

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

Formats the value using the given formatter.

impl PartialEq<DatabaseBackend> for DatabaseBackend

fn eq(&self, other: &DatabaseBackend) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for DatabaseBackend

impl Eq for DatabaseBackend

impl StructuralEq for DatabaseBackend

impl StructuralPartialEq for DatabaseBackend