Packages
ash
3.0.0-rc.45
3.29.3
3.29.2
3.29.1
3.29.0
3.28.0
3.27.8
3.27.7
3.27.6
3.27.5
3.27.4
3.27.3
3.27.2
3.27.1
3.27.0
3.26.0
3.25.2
3.25.1
3.25.0
retired
3.24.7
3.24.6
3.24.5
3.24.4
3.24.3
3.24.2
3.24.1
3.24.0
3.23.1
3.23.0
3.22.2
3.22.1
3.22.0
3.21.3
3.21.2
3.21.1
3.21.0
3.20.0
3.19.3
3.19.2
3.19.1
3.19.0
3.18.0
3.17.1
3.17.0
3.16.0
3.15.0
3.14.1
3.14.0
retired
3.13.2
3.13.1
3.13.0
3.12.0
3.11.3
3.11.2
3.11.1
3.11.0
3.10.1
3.10.0
3.9.0
3.8.0
3.7.6
3.7.5
3.7.4
3.7.3
3.7.2
3.7.1
3.7.0
retired
3.6.3
retired
3.6.2
3.6.1
3.6.0
3.5.43
3.5.42
3.5.41
3.5.40
3.5.39
3.5.38
3.5.37
3.5.36
3.5.35
3.5.34
3.5.33
3.5.32
3.5.31
3.5.30
3.5.29
3.5.28
3.5.27
3.5.26
3.5.25
3.5.24
3.5.23
3.5.22
3.5.21
3.5.20
3.5.19
3.5.18
3.5.17
3.5.16
3.5.15
3.5.14
3.5.13
3.5.12
3.5.11
3.5.10
3.5.9
3.5.8
3.5.7
3.5.6
3.5.5
3.5.4
3.5.3
3.5.2
3.5.1
3.5.0
3.4.74
retired
3.4.73
3.4.72
3.4.71
3.4.70
3.4.69
3.4.68
3.4.67
3.4.66
3.4.65
3.4.64
3.4.63
3.4.62
3.4.61
3.4.60
3.4.59
3.4.58
3.4.57
3.4.56
3.4.55
3.4.54
3.4.53
3.4.52
3.4.51
3.4.50
3.4.49
3.4.48
3.4.47
3.4.46
3.4.45
3.4.44
3.4.43
3.4.42
3.4.41
3.4.40
3.4.39
3.4.38
3.4.37
3.4.36
3.4.35
3.4.34
3.4.33
3.4.32
3.4.31
3.4.30
3.4.29
3.4.28
3.4.27
3.4.26
3.4.25
3.4.24
3.4.23
3.4.22
3.4.21
3.4.20
3.4.19
3.4.18
3.4.17
3.4.16
3.4.15
3.4.14
3.4.13
3.4.12
3.4.11
3.4.10
3.4.9
3.4.8
3.4.7
3.4.6
3.4.5
3.4.4
3.4.3
3.4.2
3.4.1
3.4.0
3.3.3
3.3.2
3.3.1
3.3.0
3.2.6
3.2.5
3.2.4
3.2.3
3.2.2
3.2.1
3.2.0
3.1.8
3.1.7
3.1.6
3.1.5
3.1.4
3.1.3
3.1.2
3.1.1
3.1.0
3.0.16
3.0.15
3.0.14
3.0.13
3.0.12
3.0.11
3.0.10
3.0.9
3.0.8
3.0.7
3.0.6
3.0.5
3.0.4
3.0.3
3.0.2
3.0.1
3.0.0
3.0.0-rc.46
3.0.0-rc.45
3.0.0-rc.44
3.0.0-rc.43
3.0.0-rc.42
3.0.0-rc.41
3.0.0-rc.40
3.0.0-rc.39
3.0.0-rc.38
3.0.0-rc.37
3.0.0-rc.36
3.0.0-rc.35
3.0.0-rc.34
3.0.0-rc.33
3.0.0-rc.32
3.0.0-rc.31
3.0.0-rc.29
3.0.0-rc.28
3.0.0-rc.27
3.0.0-rc.26
3.0.0-rc.25
3.0.0-rc.24
3.0.0-rc.23
3.0.0-rc.22
3.0.0-rc.21
3.0.0-rc.20
3.0.0-rc.19
3.0.0-rc.18
3.0.0-rc.17
3.0.0-rc.16
3.0.0-rc.15
3.0.0-rc.14
3.0.0-rc.13
3.0.0-rc.12
3.0.0-rc.11
3.0.0-rc.10
3.0.0-rc.9
3.0.0-rc.8
3.0.0-rc.7
3.0.0-rc.6
3.0.0-rc.5
3.0.0-rc.4
3.0.0-rc.3
3.0.0-rc.1
3.0.0-rc.0
2.21.15
2.21.14
2.21.13
2.21.12
2.21.11
2.21.10
2.21.9
2.21.8
2.21.7
2.21.6
2.21.5
2.21.4
2.21.3
2.21.2
2.21.1
2.21.0
2.20.3
2.20.2
2.20.1
2.20.0
2.19.14
2.19.13
2.19.12
2.19.11
2.19.10
2.19.9
2.19.8
2.19.7
2.19.6
2.19.5
2.19.4
2.19.3
retired
2.19.2
retired
2.19.1
retired
2.19.0
retired
2.18.2
2.18.1
2.18.0
2.17.24
2.17.23
2.17.22
2.17.21
2.17.20
2.17.19
2.17.18
2.17.17
2.17.16
2.17.15
2.17.14
2.17.13
2.17.12
2.17.11
2.17.10
2.17.9
2.17.8
2.17.7
2.17.6
2.17.5
2.17.4
2.17.3
2.17.2
2.17.1
2.17.0
2.16.1
2.16.0
2.15.20
2.15.19
2.15.18
2.15.17
2.15.16
2.15.15
2.15.14
2.15.13
2.15.12
2.15.11
2.15.10
2.15.9
2.15.8
2.15.7
2.15.6
2.15.5
2.15.4
2.15.2
2.15.1
2.15.0
2.14.21
2.14.20
2.14.19
2.14.18
2.14.17
2.14.16
2.14.15
2.14.14
2.14.13
2.14.12
2.14.11
2.14.10
2.14.9
2.14.8
2.14.7
2.14.6
2.14.5
2.14.4
2.14.3
2.14.2
2.14.1
2.14.0
2.13.4
retired
2.13.3
2.13.2
2.13.1
2.13.0
2.12.1
2.12.0
2.11.11
2.11.10
2.11.9
2.11.8
2.11.7
2.11.6
2.11.5
2.11.4
2.11.3
2.11.2
2.11.1
2.11.0
2.11.0-rc.3
2.11.0-rc.2
2.11.0-rc.1
2.11.0-rc.0
2.10.2
2.10.1
2.10.0
2.9.29
2.9.28
2.9.27
2.9.26
2.9.25
2.9.24
2.9.23
2.9.22
2.9.21
2.9.20
2.9.19
2.9.18
2.9.17
2.9.16
2.9.15
2.9.14
2.9.13
2.9.12
2.9.11
2.9.10
2.9.9
2.9.8
2.9.7
2.9.6
2.9.5
2.9.4
2.9.3
2.9.2
2.9.1
2.9.0
2.8.1
2.8.0
2.7.1
2.7.0
2.6.31
2.6.30
2.6.29
2.6.28
2.6.27
2.6.26
2.6.25
2.6.24
2.6.23
2.6.22
2.6.21
2.6.20
2.6.19
2.6.18
2.6.17
2.6.16
2.6.15
2.6.14
2.6.13
2.6.11
2.6.10
2.6.9
2.6.8
2.6.7
2.6.6
2.6.5
2.6.4
2.6.3
2.6.2
2.6.1
2.6.0
2.5.16
2.5.15
2.5.14
2.5.13
2.5.12
2.5.11
2.5.10
2.5.9
2.5.8
2.5.7
2.5.6
2.5.5
2.5.4
2.5.3
2.5.2
2.5.1
2.5.0
2.5.0-rc.6
2.5.0-rc.5
2.5.0-rc.4
2.5.0-rc.3
2.5.0-rc.2
2.5.0-rc.1
2.5.0-rc.0
2.4.30
2.4.29
2.4.28
2.4.27
2.4.26
2.4.25
2.4.24
2.4.23
2.4.22
2.4.21
2.4.20
2.4.19
2.4.18
2.4.17
2.4.16
2.4.15
2.4.14
2.4.13
2.4.12
2.4.11
2.4.10
2.4.9
2.4.8
2.4.7
2.4.6
2.4.5
2.4.4
2.4.3
2.4.2
2.4.1
2.4.0
2.3.0
2.2.0
2.1.0
2.0.0
2.0.0-rc.15
2.0.0-rc.14
2.0.0-rc.13
2.0.0-rc.12
2.0.0-rc.11
2.0.0-rc.10
2.0.0-rc.9
2.0.0-rc.8
2.0.0-rc.7
2.0.0-rc.6
2.0.0-rc.5
2.0.0-rc.4
2.0.0-rc.3
2.0.0-rc.2
2.0.0-rc.1
2.0.0-rc.0
2.0.0-pre.8
2.0.0-pre.7
2.0.0-pre.6
2.0.0-pre.5
2.0.0-pre.4
2.0.0-pre.3
2.0.0-pre.2
2.0.0-pre.1
2.0.0-pre.0
1.53.3
1.53.2
1.53.0
1.52.0-rc.22
1.52.0-rc.21
1.52.0-rc.20
1.52.0-rc.19
1.52.0-rc.18
1.52.0-rc.17
1.52.0-rc.16
1.52.0-rc.15
1.52.0-rc.14
1.52.0-rc.13
1.52.0-rc.12
1.52.0-rc.11
1.52.0-rc.10
1.52.0-rc.9
1.52.0-rc.8
1.52.0-rc.7
1.52.0-rc.6
1.52.0-rc.5
1.52.0-rc.4
1.52.0-rc.3
1.52.0-rc.2
1.52.0-rc.1
1.52.0-rc.0
1.51.2
1.51.1
retired
1.51.0
1.50.21
1.50.20
1.50.19
1.50.18
1.50.17
1.50.16
1.50.15
1.50.14
1.50.13
1.50.12
1.50.11
1.50.10
1.50.9
1.50.8
1.50.7
1.50.6
1.50.5
1.50.4
1.50.3
1.50.2
1.50.1
1.50.0
1.49.0
1.48.0-rc.30
1.48.0-rc.29
1.48.0-rc.28
1.48.0-rc.27
1.48.0-rc.26
1.48.0-rc.25
1.48.0-rc.24
1.48.0-rc.23
1.48.0-rc.22
1.48.0-rc.21
1.48.0-rc.20
1.48.0-rc.19
1.48.0-rc.18
1.48.0-rc.17
1.48.0-rc.16
1.48.0-rc.15
1.48.0-rc.14
1.48.0-rc.13
1.48.0-rc.12
1.48.0-rc.11
1.48.0-rc.10
1.48.0-rc.9
1.48.0-rc.8
1.48.0-rc.7
1.48.0-rc.6
1.48.0-rc.5
1.48.0-rc.4
1.48.0-rc.3
1.48.0-rc.2
1.48.0-rc.1
1.48.0-rc.0
1.47.12
1.47.11
1.47.10
1.47.9
1.47.8
1.47.7
1.47.6
1.47.5
1.47.4
1.47.3
1.47.2
1.47.1
1.47.0
1.46.13
1.46.12
1.46.11
1.46.10
1.46.9
1.46.8
1.46.7
1.46.6
1.46.5
1.46.4
1.46.3
1.46.2
1.46.1
1.46.0
1.45.0-rc9
1.45.0-rc8
1.45.0-rc7
1.45.0-rc6
1.45.0-rc5
1.45.0-rc4
1.45.0-rc3
1.45.0-rc20
1.45.0-rc2
1.45.0-rc19
1.45.0-rc18
1.45.0-rc17
1.45.0-rc16
1.45.0-rc15
1.45.0-rc14
1.45.0-rc13
1.45.0-rc12
1.45.0-rc11
1.45.0-rc10
1.45.0-rc1
1.45.0-rc0
1.44.13
1.44.12
1.44.11
1.44.10
1.44.9
1.44.8
1.44.7
1.44.6
1.44.5
1.44.4
1.44.3
1.44.2
1.44.1
1.44.0
1.43.12
1.43.11
1.43.10
1.43.9
1.43.8
1.43.7
1.43.6
1.43.5
1.43.4
1.43.3
1.43.2
1.43.1
1.43.0
1.42.0
1.41.12
1.41.11
1.41.10
1.41.9
1.41.8
1.41.7
1.41.6
1.41.5
1.41.4
1.41.3
1.41.2
1.41.1
1.41.0
1.40.0
1.39.7
1.39.6
1.39.5
1.39.4
1.39.3
1.39.2
1.39.1
1.39.0
1.38.0
1.37.2
1.37.1
1.37.0
1.36.22
1.36.21
1.36.19
1.36.18
1.36.17
1.36.16
1.36.15
1.36.14
1.36.13
1.36.12
1.36.11
1.36.10
1.36.9
1.36.8
1.36.7
1.36.6
1.36.5
1.36.4
1.36.3
1.36.2
1.36.0
1.35.1
1.35.0
1.34.9
1.34.8
1.34.7
1.34.6
1.34.5
1.34.4
1.34.3
1.34.2
1.34.1
1.34.0
1.33.0
1.32.2
1.32.1
1.32.0
1.31.1
1.31.0
1.30.2
1.30.1
1.29.0-rc1
1.29.0-rc0
1.28.1
1.28.0
1.27.1
1.27.0
1.26.13
1.26.12
1.26.11
1.26.10
1.26.9
1.26.8
1.26.7
1.26.6
1.26.5
1.26.4
1.26.2
1.26.1
1.26.0
1.25.8
1.25.7
1.25.6
1.25.5
1.25.4
1.25.3
1.25.2
1.25.1
1.25.0
1.24.2
1.24.1
1.24.0
1.23.3
1.23.2
1.23.1
1.23.0
1.22.1
1.22.0
1.20.1
1.20.0
1.19.1
1.19.0
1.18.1
1.18.0
1.17.1
1.17.0
1.16.2
1.15.1
1.15.0
1.14.0
1.13.4
1.13.3
1.13.2
1.13.1
1.13.0
1.12.0
1.11.1
1.11.0
1.10.0
1.9.0
1.8.0
1.7.0
1.6.8
1.6.7
1.6.6
1.6.5
1.6.4
1.6.3
1.6.2
1.6.1
1.6.0
1.5.1
1.5.0
1.4.1
1.4.0
1.3.1
1.3.0
1.2.1
1.2.0
1.1.3
1.1.2
1.1.0
1.0.3
1.0.2
1.0.1
1.0.0
0.13.1
0.13.0
0.12.0
0.10.0
0.9.1
0.9.0
0.8.0
0.7.0
0.6.5
0.6.4
0.6.3
0.6.2
0.6.1
0.6.0
0.5.2
0.5.1
0.5.0
0.4.0
0.3.0
0.2.0
0.1.9
0.1.8
0.1.3
0.1.1
0.1.0
A declarative, extensible framework for building Elixir applications.
Security advisory:
This version has known vulnerabilities.
View advisories
Current section
Files
Jump to
Current section
Files
documentation/how-to/cook-book/optimistic-locking.livemd
<!-- livebook:{"persist_outputs":true} -->
# Optimistic Locking
```elixir
Mix.install([{:ash, "~> 3.0.0-rc"}], consolidate_protocols: false)
Logger.configure(level: :debug)
```
## What is optimistic locking?
Optimistic Locking is the process of only allowing an update to occur if the version of a record that you have in memory is the same as the version in the database. Otherwise, an error is returned.
Optimistic locking may used for two primary purposes:
### User Experience
For example, if a user is editing a form that contains `State` and `County` fields, and they change the `County`, while another user has used the form to change the `State`, you could end up with a mismatch between `State` and `County`.
With optimistic locking, the user will instead get an error message that the record has been changed since they last looked.
### Concurrency Safety
Optimistic locking can make actions safe to run concurrently even if they can't be performed in a single query(atomically), by returning an error if the resource in the data layer does not have the same version as the one being edited.
This tells the user that they need to reload and try again.
### Want to see how it works
Modify the setup block and configure the log level to debug to see logs from the ETS data layer.
<!-- livebook:{"force_markdown":true} -->
```elixir
Logger.configure(level: :debug)
```
## Define a resource with a version attribute
```elixir
defmodule Address do
use Ash.Resource,
domain: Domain,
data_layer: Ash.DataLayer.Ets
attributes do
uuid_primary_key(:id)
attribute(:version, :integer, allow_nil?: false, default: 1)
attribute(:state, :string, allow_nil?: false)
attribute(:county, :string, allow_nil?: false)
end
actions do
defaults([:read, create: [:state, :county]])
update :update do
accept([:state, :county])
change(optimistic_lock(:version))
end
end
end
defmodule Domain do
use Ash.Domain,
validate_config_inclusion?: false
resources do
resource Address do
define(:get_address, action: :read, get_by: [:id])
define(:create_address, action: :create, args: [:state, :county])
define(:update_address, action: :update)
end
end
end
```
<!-- livebook:{"output":true} -->
```
{:module, Domain, <<70, 79, 82, 49, 0, 1, 254, ...>>,
[
Ash.Domain.Dsl.Resources.Resource,
Ash.Domain.Dsl.Resources.Options,
Ash.Domain.Dsl,
%{opts: [], entities: [...]},
Ash.Domain.Dsl,
Ash.Domain.Dsl.Resources.Options,
...
]}
```
## Trigger a StaleRecord error
```elixir
address = Domain.create_address!("FL", "Pinellas")
Domain.update_address!(address, %{state: "NC", county: "Guilford"})
# `address` still has a version of `1`, so our optimistic lock should catch it!
Domain.update_address(address, %{county: "Miami-Dade"})
```
<!-- livebook:{"output":true} -->
```
06:59:29.507 [debug] Creating Address:
%{
id: "8b79d3c4-807d-4756-a46e-eae7da020122",
version: 1,
state: "FL",
county: "Pinellas"
}
:error
{:ok,
%{
extra: %{},
name: :if,
arguments: [
%{
left: %{
attribute: %{
default: 1,
name: :version,
type: Ash.Type.Integer,
description: nil,
source: :version,
__struct__: Ash.Resource.Attribute,
constraints: [],
primary_key?: false,
public?: false,
sensitive?: false,
allow_nil?: false,
update_default: nil,
writable?: true,
generated?: false,
always_select?: false,
match_other_defaults?: false,
filterable?: true,
sortable?: true
},
resource: Address,
__struct__: Ash.Query.Ref,
simple_equality?: nil,
relationship_path: [],
input?: false,
bare?: nil
},
right: 1,
operator: :==,
__struct__: Ash.Query.Operator.Eq,
embedded?: false,
__predicate__?: true,
__operator__?: true
},
%{
left: %{
attribute: %{
default: 1,
name: :version,
type: Ash.Type.Integer,
description: nil,
source: :version,
__struct__: Ash.Resource.Attribute,
constraints: [],
primary_key?: false,
public?: false,
sensitive?: false,
allow_nil?: false,
update_default: nil,
writable?: true,
generated?: false,
always_select?: false,
match_other_defaults?: false,
filterable?: true,
sortable?: true
},
resource: Address,
__struct__: Ash.Query.Ref,
simple_equality?: nil,
relationship_path: [],
input?: false,
bare?: nil
},
right: 1,
operator: :+,
__struct__: Ash.Query.Operator.Basic.Plus,
embedded?: false,
__predicate__?: false,
__operator__?: true
},
%{
extra: %{},
name: :error,
arguments: [
Ash.Error.Changes.StaleRecord,
%{filter: %{version: 1}, resource: "Address"}
],
__struct__: Ash.Query.Function.Error,
embedded?: false,
__predicate__?: false,
__function__?: true
}
],
__struct__: Ash.Query.Function.If,
embedded?: false,
__predicate__?: false,
__function__?: true
}}
%{
extra: %{},
name: :if,
arguments: [
%{
left: %{
attribute: %{
default: 1,
name: :version,
type: Ash.Type.Integer,
description: nil,
source: :version,
__struct__: Ash.Resource.Attribute,
constraints: [],
primary_key?: false,
public?: false,
sensitive?: false,
allow_nil?: false,
update_default: nil,
writable?: true,
generated?: false,
always_select?: false,
match_other_defaults?: false,
filterable?: true,
sortable?: true
},
resource: Address,
__struct__: Ash.Query.Ref,
simple_equality?: nil,
relationship_path: [],
input?: false,
bare?: nil
},
right: 1,
operator: :==,
__struct__: Ash.Query.Operator.Eq,
embedded?: false,
__predicate__?: true,
__operator__?: true
},
%{
left: %{
attribute: %{
default: 1,
name: :version,
type: Ash.Type.Integer,
description: nil,
source: :version,
__struct__: Ash.Resource.Attribute,
constraints: [],
primary_key?: false,
public?: false,
sensitive?: false,
allow_nil?: false,
update_default: nil,
writable?: true,
generated?: false,
always_select?: false,
match_other_defaults?: false,
filterable?: true,
sortable?: true
},
resource: Address,
__struct__: Ash.Query.Ref,
simple_equality?: nil,
relationship_path: [],
input?: false,
bare?: nil
},
right: 1,
operator: :+,
__struct__: Ash.Query.Operator.Basic.Plus,
embedded?: false,
__predicate__?: false,
__operator__?: true
},
%{
extra: %{},
name: :error,
arguments: [
Ash.Error.Changes.StaleRecord,
%{filter: %{version: 1}, resource: "Address"}
],
__struct__: Ash.Query.Function.Error,
embedded?: false,
__predicate__?: false,
__function__?: true
}
],
__struct__: Ash.Query.Function.If,
embedded?: false,
__predicate__?: false,
__function__?: true
}
true
:error
06:59:29.515 [debug] ETS: Updating Address matching filter `id == "8b79d3c4-807d-4756-a46e-eae7da020122"`:
%{
version: required!(if version == 1 do
version + 1
else
error(
Ash.Error.Changes.StaleRecord,
%{filter: %{version: 1}, resource: "Address"}
)
end),
state: "NC",
county: "Guilford"
}
:error
{:ok,
%{
extra: %{},
name: :if,
arguments: [
%{
left: %{
attribute: %{
default: 1,
name: :version,
type: Ash.Type.Integer,
description: nil,
source: :version,
__struct__: Ash.Resource.Attribute,
constraints: [],
primary_key?: false,
public?: false,
sensitive?: false,
allow_nil?: false,
update_default: nil,
writable?: true,
generated?: false,
always_select?: false,
match_other_defaults?: false,
filterable?: true,
sortable?: true
},
resource: Address,
__struct__: Ash.Query.Ref,
simple_equality?: nil,
relationship_path: [],
input?: false,
bare?: nil
},
right: 1,
operator: :==,
__struct__: Ash.Query.Operator.Eq,
embedded?: false,
__predicate__?: true,
__operator__?: true
},
%{
left: %{
attribute: %{
default: 1,
name: :version,
type: Ash.Type.Integer,
description: nil,
source: :version,
__struct__: Ash.Resource.Attribute,
constraints: [],
primary_key?: false,
public?: false,
sensitive?: false,
allow_nil?: false,
update_default: nil,
writable?: true,
generated?: false,
always_select?: false,
match_other_defaults?: false,
filterable?: true,
sortable?: true
},
resource: Address,
__struct__: Ash.Query.Ref,
simple_equality?: nil,
relationship_path: [],
input?: false,
bare?: nil
},
right: 1,
operator: :+,
__struct__: Ash.Query.Operator.Basic.Plus,
embedded?: false,
__predicate__?: false,
__operator__?: true
},
%{
extra: %{},
name: :error,
arguments: [
Ash.Error.Changes.StaleRecord,
%{filter: %{version: 1}, resource: "Address"}
],
__struct__: Ash.Query.Function.Error,
embedded?: false,
__predicate__?: false,
__function__?: true
}
],
__struct__: Ash.Query.Function.If,
embedded?: false,
__predicate__?: false,
__function__?: true
}}
%{
extra: %{},
name: :if,
arguments: [
%{
left: %{
attribute: %{
default: 1,
name: :version,
type: Ash.Type.Integer,
description: nil,
source: :version,
__struct__: Ash.Resource.Attribute,
constraints: [],
primary_key?: false,
public?: false,
sensitive?: false,
allow_nil?: false,
update_default: nil,
writable?: true,
generated?: false,
always_select?: false,
match_other_defaults?: false,
filterable?: true,
sortable?: true
},
resource: Address,
__struct__: Ash.Query.Ref,
simple_equality?: nil,
relationship_path: [],
input?: false,
bare?: nil
},
right: 1,
operator: :==,
__struct__: Ash.Query.Operator.Eq,
embedded?: false,
__predicate__?: true,
__operator__?: true
},
%{
left: %{
attribute: %{
default: 1,
name: :version,
type: Ash.Type.Integer,
description: nil,
source: :version,
__struct__: Ash.Resource.Attribute,
constraints: [],
primary_key?: false,
public?: false,
sensitive?: false,
allow_nil?: false,
update_default: nil,
writable?: true,
generated?: false,
always_select?: false,
match_other_defaults?: false,
filterable?: true,
sortable?: true
},
resource: Address,
__struct__: Ash.Query.Ref,
simple_equality?: nil,
relationship_path: [],
input?: false,
bare?: nil
},
right: 1,
operator: :+,
__struct__: Ash.Query.Operator.Basic.Plus,
embedded?: false,
__predicate__?: false,
__operator__?: true
},
%{
extra: %{},
name: :error,
arguments: [
Ash.Error.Changes.StaleRecord,
%{filter: %{version: 1}, resource: "Address"}
],
__struct__: Ash.Query.Function.Error,
embedded?: false,
__predicate__?: false,
__function__?: true
}
],
__struct__: Ash.Query.Function.If,
embedded?: false,
__predicate__?: false,
__function__?: true
}
true
:error
06:59:29.527 [debug] ETS: Updating Address matching filter `id == "8b79d3c4-807d-4756-a46e-eae7da020122"`:
%{
version: required!(if version == 1 do
version + 1
else
error(
Ash.Error.Changes.StaleRecord,
%{filter: %{version: 1}, resource: "Address"}
)
end),
county: "Miami-Dade"
}
```
<!-- livebook:{"output":true} -->
```
{:error,
%Ash.Error.Invalid{
changeset: nil,
query: nil,
action_input: nil,
errors: [
%Ash.Error.Changes.StaleRecord{
resource: "Address",
filter: %{"version" => 1},
splode: Ash.Error,
bread_crumbs: [],
vars: [],
path: [],
stacktrace: #Splode.Stacktrace<>,
class: :invalid
}
],
splode: Ash.Error,
bread_crumbs: [],
vars: [],
path: [],
stacktrace: #Splode.Stacktrace<>,
class: :invalid
}}
```
## Refetching a record to get the latest version
```elixir
address = Domain.create_address!("FL", "Pinellas")
Domain.update_address!(address, %{state: "NC", county: "Guilford"})
case Domain.update_address(address, %{county: "Miami-Dade"}) do
{:error, %Ash.Error.Invalid{errors: [%Ash.Error.Changes.StaleRecord{}]}} ->
# In a liveview, you wouldn't jsut refetch and resubmit
# you would show the user an error and have them submit the form again
address = Domain.get_address!(address.id)
Domain.update_address!(address, %{county: "Miami-Dade"})
{:ok, domain} ->
domain
end
```
<!-- livebook:{"output":true} -->
```
#Address<
__meta__: #Ecto.Schema.Metadata<:loaded>,
id: "f2bdbd9e-4946-4df5-8608-0777900e1b47",
version: 3,
state: "NC",
county: "Miami-Dade",
aggregates: %{},
calculations: %{},
...
>
```