如何对OR逻辑进行条件验证,我们检查2个值中的1个是否存在或两个值都存在。
因此,例如,如果我想检查以确保email
或mobile
字段已填充......我希望能够将列表传递到fields
validate_required_inclusion
,以验证列表中至少有 1 个字段不为空。
def changeset(struct, params \ %{}) do
struct
|> cast(params, [:email, :first_name, :last_name, :password_hash, :role, :birthdate, :address1, :address2, :city, :state, :zip, :status, :mobile, :card, :sms_code, :status])
|> validate_required_inclusion([:email , :mobile])
end
def validate_required_inclusion(changeset, fields, options \ []) do
end
如何执行此条件 OR 验证?
这是一个简单的方法。您可以自定义它以支持更好的错误消息:
def validate_required_inclusion(changeset, fields) do
if Enum.any?(fields, &present?(changeset, &1)) do
changeset
else
# Add the error to the first field only since Ecto requires a field name for each error.
add_error(changeset, hd(fields), "One of these fields must be present: #{inspect fields}")
end
end
def present?(changeset, field) do
value = get_field(changeset, field)
value && value != ""
end
使用Post模型进行测试,|> validate_required_inclusion([:title , :content])
:
iex(1)> Post.changeset(%Post{}, %{})
#Ecto.Changeset<action: nil, changes: %{},
errors: [title: {"One of these fields must be present: [:title, :content]",
[]}], data: #MyApp.Post<>, valid?: false>
iex(2)> Post.changeset(%Post{}, %{title: ""})
#Ecto.Changeset<action: nil, changes: %{},
errors: [title: {"One of these fields must be present: [:title, :content]",
[]}], data: #MyApp.Post<>, valid?: false>
iex(3)> Post.changeset(%Post{}, %{title: "foo"})
#Ecto.Changeset<action: nil, changes: %{title: "foo"}, errors: [],
data: #MyApp.Post<>, valid?: true>
iex(4)> Post.changeset(%Post{}, %{content: ""})
#Ecto.Changeset<action: nil, changes: %{},
errors: [title: {"One of these fields must be present: [:title, :content]",
[]}], data: #MyApp.Post<>, valid?: false>
iex(5)> Post.changeset(%Post{}, %{content: "foo"})
#Ecto.Changeset<action: nil, changes: %{content: "foo"}, errors: [],
data: #MyApp.Post<>, valid?: true>
您还可以在数据库中创建约束,例如通过编写迁移:
create(
constraint(
:users,
:email_or_mobile,
check: "(email IS NOT NULL) OR (mobile IS NOT NULL)"
)
)
并使用 check_constraint
来验证变更集:
def changeset(struct, params \ %{}) do
struct
|> cast(params, [:email, :first_name, :last_name, :password_hash, :role, :birthdate, :address1, :address2, :city, :state, :zip, :status, :mobile, :card, :sms_code, :status])
|> check_constraint(
:users_table,
name: :email_or_mobile,
message: dgettext("errors", "can't be blank")
)
end
怎么样:
def validate_required_inclusion(changeset, fields, options \ []) do
if Enum.any?(fields, fn(field) -> get_field(changeset, field) end),
do: changeset,
else: add_error(changeset, hd(fields), "One of these fields must be present: #{inspect fields}")
end
get_field
为您提供更改集接受的字段,包括已更改(强制转换(和未更改的字段,以及 Enum.any? 将确保至少有一个字段位于其中。