Represents a live connection to a Postgres database. Operations provided here are safe to use
concurrently. Note that this is a lifetime-managed resource and as such is invalid outside the
scope of its owning Resource
, as are any streams constructed here. If you start
an operation
be sure to join
its Fiber
before releasing the resource.
See the companion object for information on obtaining a pooled or single-use instance.
Attributes
- Companion:
- object
- Source:
- Session.scala
- Graph
- Supertypes
- class Objecttrait Matchableclass Any
- Known subtypes
- class Impl[F]
Members list
Queries
A query is any SQL statement that returns rows; i.e., any SELECT
or
VALUES
query, or an INSERT
, UPDATE
, or DELETE
command that returns rows via RETURNING
.
Parameterized queries must first be prepared, then can be executed many times with different
arguments. Non-parameterized queries can be executed directly.
Execute a non-parameterized query and yield all results. If you have parameters or wish to limit
returned rows use prepare
instead.
Execute a non-parameterized query and yield all results. If you have parameters or wish to limit
returned rows use prepare
instead.
Attributes
- Source:
- Session.scala
Prepare if needed, then execute a parameterized query and yield all results. If you wish to limit
returned rows use prepare
instead.
Prepare if needed, then execute a parameterized query and yield all results. If you wish to limit
returned rows use prepare
instead.
Attributes
- Source:
- Session.scala
Execute a non-parameterized query and yield at most one row, raising an exception if there are
more. If you have parameters use prepare
instead.
Execute a non-parameterized query and yield at most one row, raising an exception if there are
more. If you have parameters use prepare
instead.
Attributes
- Source:
- Session.scala
Prepare if needed, then execute a parameterized query and yield at most one row, raising an exception if there are more.
Prepare if needed, then execute a parameterized query and yield at most one row, raising an exception if there are more.
Attributes
- Source:
- Session.scala
Prepares then caches a query, yielding a PreparedQuery
which can be executed multiple
times with different arguments.
Prepares then caches a query, yielding a PreparedQuery
which can be executed multiple
times with different arguments.
Attributes
- Source:
- Session.scala
Resource that prepares a query, yielding a PreparedQuery
which can be executed multiple
times with different arguments.
Resource that prepares a query, yielding a PreparedQuery
which can be executed multiple
times with different arguments.
Note: this method only exists to ease migration from Skunk 0.3 and prior. Use the non-resource variant instead.
Attributes
- Source:
- Session.scala
Execute a non-parameterized query and yield exactly one row, raising an exception if there are
more or fewer. If you have parameters use prepare
instead.
Execute a non-parameterized query and yield exactly one row, raising an exception if there are
more or fewer. If you have parameters use prepare
instead.
Attributes
- Source:
- Session.scala
Prepare if needed, then execute a parameterized query and yield exactly one row, raising an exception if there are more or fewer.
Prepare if needed, then execute a parameterized query and yield exactly one row, raising an exception if there are more or fewer.
Attributes
- Source:
- Session.scala
Commands
A command is any SQL statement that cannot return rows. Parameterized commands must first be prepared, then can be executed many times with different arguments. Commands without parameters can be executed directly.
Execute a non-parameterized command and yield a Completion
. If you have parameters use
prepare
instead.
Execute a non-parameterized command and yield a Completion
. If you have parameters use
prepare
instead.
Attributes
- Source:
- Session.scala
Prepare if needed, then execute a parameterized command and yield a Completion
.
Prepare if needed, then execute a parameterized command and yield a Completion
.
Attributes
- Source:
- Session.scala
Transform a Command
into a Pipe
from inputs to Completion
s.
Transform a Query
into a Pipe
from inputs to outputs.
Transform a Query
into a Pipe
from inputs to outputs.
Attributes
- chunkSize
how many rows must be fetched by page
- Source:
- Session.scala
Prepares then caches an INSERT
, UPDATE
, or DELETE
command that returns no rows. The resulting
PreparedCommand
can be executed multiple times with different arguments.
Prepares then caches an INSERT
, UPDATE
, or DELETE
command that returns no rows. The resulting
PreparedCommand
can be executed multiple times with different arguments.
Attributes
- Source:
- Session.scala
Prepare an INSERT
, UPDATE
, or DELETE
command that returns no rows. The resulting
PreparedCommand
can be executed multiple times with different arguments.
Prepare an INSERT
, UPDATE
, or DELETE
command that returns no rows. The resulting
PreparedCommand
can be executed multiple times with different arguments.
Note: this method only exists to ease migration from Skunk 0.3 and prior. Use the non-resource variant instead.
Attributes
- Source:
- Session.scala
Transactions
Users can manipulate transactions directly via commands like BEGIN
and
COMMIT
, but dealing with cancellation and error conditions can be complicated and repetitive.
Skunk provides managed transaction blocks to make this easier.
Resource that wraps a transaction block. A transaction is begun before entering the use
block, on success the block is executed, and on exit the following behavior holds.
Resource that wraps a transaction block. A transaction is begun before entering the use
block, on success the block is executed, and on exit the following behavior holds.
- If the block exits normally, and the session transaction status is
Active
, then the transaction will be committed.Idle
, then this means the user terminated the transaction explicitly inside the block and there is nothing to be done.Error
then this means the user encountered and handled an error but left the transaction in a failed state, and the transaction will be rolled back.
- If the block exits due to cancellation or an error and the session transaction status is
not
Idle
then the transaction will be rolled back and any error will be re-raised.
Attributes
- Source:
- Session.scala
Resource that wraps a transaction block. It has the ability to specify a non-default isolation level and access mode.
Resource that wraps a transaction block. It has the ability to specify a non-default isolation level and access mode.
Attributes
- See also:
Session#transaction for more information
- Source:
- Session.scala
Channels
A named asynchronous channel that can be used for inter-process communication.
A named asynchronous channel that can be used for inter-process communication.
Attributes
- Source:
- Session.scala
Session Environment
The Postgres session has a dynamic environment that includes a
configuration map with keys like TimeZone
and server_version
, as well as a current
TransactionStatus
. These can change asynchronously and are exposed as Signal
s. Note that
any Stream
based on these signals is only valid for the lifetime of the Session
.
Stream (possibly empty) of discrete values for the specified key, via parameters
.
Stream (possibly empty) of discrete values for the specified key, via parameters
.
Attributes
- Source:
- Session.scala
Signal representing the current state of all Postgres configuration variables announced to this session. These are sent after authentication and are updated asynchronously if the runtime environment changes. The current keys are as follows (with example values), but these may change with future releases so you should be prepared to handle unexpected ones.
Signal representing the current state of all Postgres configuration variables announced to this session. These are sent after authentication and are updated asynchronously if the runtime environment changes. The current keys are as follows (with example values), but these may change with future releases so you should be prepared to handle unexpected ones.
Map(
"application_name" -> "",
"client_encoding" -> "UTF8",
"DateStyle" -> "ISO, MDY",
"integer_datetimes" -> "on", // cannot change after startup
"IntervalStyle" -> "postgres",
"is_superuser" -> "on",
"server_encoding" -> "UTF8", // cannot change after startup
"server_version" -> "9.5.3", // cannot change after startup
"session_authorization" -> "postgres",
"standard_conforming_strings" -> "on",
"TimeZone" -> "US/Pacific",
)
Attributes
- Source:
- Session.scala
Signal representing the current transaction status.
Transformations
Transform this Session
by a given FunctionK
.
Value members
Abstract methods
Each session has access to the pool-wide cache of all statements that have been checked via the
Describe
protocol, which allows us to skip subsequent checks. Users can inspect and clear
the cache through this accessor.
Each session has access to the pool-wide cache of all statements that have been checked via the
Describe
protocol, which allows us to skip subsequent checks. Users can inspect and clear
the cache through this accessor.
Attributes
- Source:
- Session.scala
Each session has access to a cache of all statements that have been parsed by the
Parse
protocol, which allows us to skip a network round-trip. Users can inspect and clear
the cache through this accessor.
Each session has access to a cache of all statements that have been parsed by the
Parse
protocol, which allows us to skip a network round-trip. Users can inspect and clear
the cache through this accessor.
Attributes
- Source:
- Session.scala
Attributes
- Source:
- Session.scala