Struct diesel::pg::TransactionBuilder

#[must_use = "Transaction builder does nothing unless you call `run` on it"]
pub struct TransactionBuilder<'a> { /* fields omitted */ }

Used to build a transaction, specifying additional details.

This struct is returned by .build_transaction. See the documentation for methods on this struct for usage examples. See the PostgreSQL documentation for SET TRANSACTION for details on the behavior of each option.

Methods

impl<'a> TransactionBuilder<'a>

pub fn read_only(self) -> Self

Makes the transaction READ ONLY

Example

conn.build_transaction()
    .read_only()
    .run::<_, diesel::result::Error, _>(|| {
        let read_attempt = users.select(name).load::<String>(&conn);
        assert!(read_attempt.is_ok());

        let write_attempt = diesel::insert_into(users)
            .values(name.eq("Ruby"))
            .execute(&conn);
        assert!(write_attempt.is_err());

        Ok(())
    })?;

pub fn read_write(self) -> Self

Makes the transaction READ WRITE

This is the default, unless you've changed the default_transaction_read_only configuration parameter.

Example

conn.build_transaction()
    .read_write()
    .run(|| {
        let read_attempt = users.select(name).load::<String>(&conn);
        assert!(read_attempt.is_ok());

        let write_attempt = diesel::insert_into(users)
            .values(name.eq("Ruby"))
            .execute(&conn);
        assert!(write_attempt.is_ok());

        Ok(())
    })

pub fn deferrable(self) -> Self

Makes the transaction DEFERRABLE

Example

conn.build_transaction()
    .deferrable()
    .run(|| Ok(()))

pub fn not_deferrable(self) -> Self

Makes the transaction NOT DEFERRABLE

This is the default, unless you've changed the default_transaction_deferrable configuration parameter.

Example

conn.build_transaction()
    .not_deferrable()
    .run(|| Ok(()))

pub fn read_committed(self) -> Self

Makes the transaction ISOLATION LEVEL READ COMMITTED

This is the default, unless you've changed the default_transaction_isolation_level configuration parameter.

Example

conn.build_transaction()
    .read_committed()
    .run(|| Ok(()))

pub fn repeatable_read(self) -> Self

Makes the transaction ISOLATION LEVEL REPEATABLE READ

Example

conn.build_transaction()
    .repeatable_read()
    .run(|| Ok(()))

pub fn serializable(self) -> Self

Makes the transaction ISOLATION LEVEL SERIALIZABLE

Example

conn.build_transaction()
    .serializable()
    .run(|| Ok(()))

pub fn run<T, E, F>(&self, f: F) -> Result<T, E> where
    F: FnOnce() -> Result<T, E>,
    E: From<Error>, 

Runs the given function inside of the transaction with the parameters given to this builder.

Returns an error if the connection is already inside a transaction.

Trait Implementations

impl<'a> QueryFragment<Pg> for TransactionBuilder<'a>

fn walk_ast(&self, out: AstPass<Pg>) -> QueryResult<()>

Walk over this QueryFragment for all passes.

fn to_sql(&self, out: &mut DB::QueryBuilder) -> QueryResult<()>

Converts this QueryFragment to its SQL representation.

fn collect_binds(
    &self,
    out: &mut DB::BindCollector,
    metadata_lookup: &DB::MetadataLookup
) -> QueryResult<()>

Serializes all bind parameters in this query.

fn is_safe_to_cache_prepared(&self) -> QueryResult<bool>

Is this query safe to store in the prepared statement cache?

impl<'a> Clone for TransactionBuilder<'a>

fn clone(&self) -> TransactionBuilder<'a>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for TransactionBuilder<'a>