Advanced Usage
Transaction Options
Transactions can be customized with different options:
class
TransactionOptions
TransactionOptions(isolation = IsolationLevel.Serializable, readonly = False, deferrable = False)
Parameters
isolation
(IsolationLevel) – transaction isolation levelreadonly
(bool) – if true the transaction will be readonlydeferrable
(bool) – if true the transaction will be deferrable
classmethod
TransactionOptions.defaults()
Returns the default TransactionOptions.
class
IsolationLevel
Isolation level for transaction
attribute
IsolationLevel.Serializable
Serializable isolation level
TransactionOptions can be set on Client or AsyncIOClient using one of these methods:
These methods return a “shallow copy” of the current client object with modified transaction options. Both self
and the returned object can be used, but different transaction options will applied respectively.
Transaction options are used by the future calls to the method edgedb.Client.transaction() or edgedb.AsyncIOClient.transaction().
Retry Options
Individual EdgeQL commands or whole transaction blocks are automatically retried on retryable errors. By default, edgedb-python will try at most 3 times, with an exponential backoff time interval starting from 100ms, plus a random hash under 100ms.
Retry rules can be granularly customized with different retry options:
class
RetryOptions
RetryOptions(attempts, backoff = default_backoff)
Parameters
attempts
(int) – the default number of attemptsbackoff
(Callable
[
[
int]
**,
Union
**[
float,
int]
**]
) – the default backoff function
method
RetryOptions.with_rule()
RetryOptions.with_rule(condition, attempts = None, backoff = None)
Adds a backoff rule for a particular condition
Parameters
condition
(RetryCondition) – condition that will trigger this ruleattempts
(int) – number of times to retrybackoff
(Callable
[
[
int]
**,
Union
**[
float,
int]
**]
) – function taking the current attempt number and returning the number of seconds to wait before the next attempt
classmethod
RetryOptions.defaults()
Returns the default RetryOptions.
class
RetryCondition
Specific condition to retry on for fine-grained control
attribute
RetryCondition.TransactionConflict
Triggered when a TransactionConflictError occurs.
attribute
RetryCondition.NetworkError
Triggered when a ClientError occurs.
RetryOptions can be set on Client or AsyncIOClient using one of these methods:
These methods return a “shallow copy” of the current client object with modified retry options. Both self
and the returned object can be used, but different retry options will applied respectively.
State
State is an execution context that affects the execution of EdgeQL commands in different ways: default module, module aliases, session config and global values.
class
State
State(default_module = None, module_aliases = {}, config = {}, globals_ = {})
Parameters
default_module
(stror
None) – The default module that the future commands will be executed with.None
means the default default module on the server-side, which is usually justdefault
.module_aliases
(dict[
str,
str]
) – Module aliases mapping of alias -> target module.config
(dict[
str,
object]
) – Non system-level config settings mapping of config name -> config value.For available configuration parameters refer to the Config documentation.globals
(dict[
str,
object]
) – Global values mapping of global name -> global value.The global name can be either a qualified name like
my_mod::glob2
, or a simple name under the default module. Simple names will be prefixed with the default module, while module aliases in qualified names - if any - will be resolved into actual module names.
method
State.with_default_module()
State.with_default_module(module = None)
Returns a new State copy with adjusted default module.
This will not affect the globals that are already stored in this state using simple names, because their names were resolved before this call to with_default_module()
, which affects only the future calls to the with_globals() method.
This is equivalent to using the set module
command, or using the reset module
command when giving None
.
Parameters
module
(str or
None) – Adjust the default module. If module
is None
, the default module will be reset to default.
method
State.with_module_aliases()
State.with_module_aliases(aliases_dict = None, /, ** aliases)
Returns a new State copy with adjusted module aliases.
This will not affect the globals that are already stored in this state using module aliases, because their names were resolved before this call to with_module_aliases()
, which affects only the future calls to the with_globals() method.
This is equivalent to using the set alias
command.
Parameters
aliases_dict
(dict[
str,
str] or
None) – Adjust the module aliases by merging with the given alias -> target module mapping. This is an optional positional-only argument.aliases
(dict[
str,
str]
) – Adjust the module aliases by merging with the given alias -> target module mapping, after applyingaliases_dict
if set.
method
State.without_module_aliases()
State.without_module_aliases(* aliases)
Returns a new State copy without specified module aliases.
This will not affect the globals that are already stored in this state using module aliases, because their names were resolved before this call to without_module_aliases()
, which affects only the future calls to the with_globals() method.
This is equivalent to using the reset alias
command.
Parameters
aliases
(tuple[
str]
) – Adjust the module aliases by dropping the specified aliases if they were set, no errors will be raised if they weren’t.If no aliases were given, all module aliases will be dropped.
method
State.with_config()
State.with_config(config_dict = None, /, ** config)
Returns a new State copy with adjusted session config.
This is equivalent to using the configure session set
command.
Parameters
config_dict
(dict[
str,
object] or
None) – Adjust the config settings by merging with the given config name -> config value mapping. This is an optional positional-only argument.config
(dict[
str,
object]
) – Adjust the config settings by merging with the given config name -> config value mapping, after applyingconfig_dict
if set.
method
State.without_config()
State.without_config(* config_names)
Returns a new State copy without specified session config.
This is equivalent to using the configure session reset
command.
Parameters
config_names
(tuple[
str]
) – Adjust the config settings by resetting the specified config to default if they were set, no errors will be raised if they weren’t.If no names were given, all session config will be reset.
method
State.with_globals()
State.with_globals(globals_dict = None, /, ** globals_)
Returns a new State copy with adjusted global values.
The globals are stored with their names resolved into the actual fully-qualified names using the current default module and module aliases set on this state.
This is equivalent to using the set global
command.
Parameters
globals_dict
(dict[
str,
object] or
None) – Adjust the global values by merging with the given global name -> global value mapping. This is an optional positional-only argument.globals
(dict[
str,
object]
) – Adjust the global values by merging with the given global name -> global value mapping, after applyingglobals_dict
if set.
method
State.without_globals()
State.without_globals(* global_names)
Returns a new State copy without specified globals.
This is equivalent to using the reset global
command.
Parameters
global_names
(tuple[
str]
) – Adjust the globals by resetting the specified globals to default if they were set, no errors will be raised if they weren’t.If no names were given, all globals will be reset.
State can be set on Client or AsyncIOClient using one of these methods:
These methods return a “shallow copy” of the current client object with modified state, affecting all future commands executed using the returned copy. Both self
and the returned object can be used, but different state will applied respectively.
Alternatively, shortcuts are available on client objects:
They work the same way as with_state
, and adjusts the corresponding state values.