New Type
You can define a New Type (T
) and use it as model field. The following traits have to be implemented.
- Implement
From<T>
forsea_query::Value
- Implement
sea_orm::TryGetable
forT
- Implement
sea_query::ValueType
forT
- Implement
sea_query::Nullable
forT
Wrapper Type
You can create new types wrapping any type supported by SeaORM.
use sea_orm::entity::prelude::*;
#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
#[sea_orm(table_name = "custom_value_type")]
pub struct Model {
#[sea_orm(primary_key)]
pub id: i32,
pub number: Integer,
}
#[derive(Clone, Debug, PartialEq, Eq, DeriveValueType)]
pub struct Integer(i32);
Which Integer
expands to:
#[automatically_derived]
impl std::convert::From<Integer> for sea_orm::Value {
fn from(source: Integer) -> Self {
source.0.into()
}
}
#[automatically_derived]
impl sea_orm::TryGetable for Integer {
fn try_get_by<I: sea_orm::ColIdx>(res: &sea_orm::QueryResult, idx: I)
-> std::result::Result<Self, sea_orm::TryGetError> {
<i32 as sea_orm::TryGetable>::try_get_by(res, idx).map(|v| Integer(v))
}
}
#[automatically_derived]
impl sea_orm::sea_query::ValueType for Integer {
fn try_from(v: sea_orm::Value) -> std::result::Result<Self, sea_orm::sea_query::ValueTypeErr> {
<i32 as sea_orm::sea_query::ValueType>::try_from(v).map(|v| Integer(v))
}
fn type_name() -> std::string::String {
stringify!(Integer).to_owned()
}
fn array_type() -> sea_orm::sea_query::ArrayType {
sea_orm::sea_query::ArrayType::Int
}
fn column_type() -> sea_orm::sea_query::ColumnType {
sea_orm::sea_query::ColumnType::Integer
}
}
#[automatically_derived]
impl sea_orm::sea_query::Nullable for Integer {
fn null() -> sea_orm::Value {
<i32 as sea_orm::sea_query::Nullable>::null()
}
}
Wrapping Vec<T>
(Postgres only)
use sea_orm::entity::prelude::*;
#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
#[sea_orm(table_name = "custom_vec_type")]
pub struct Model {
#[sea_orm(primary_key)]
pub id: i32,
pub str_vec: StringVec,
}
#[derive(Clone, Debug, PartialEq, Eq, DeriveValueType)]
pub struct StringVec(pub Vec<String>);
Which StringVec
expands to:
#[automatically_derived]
impl std::convert::From<StringVec> for Value {
fn from(source: StringVec) -> Self {
source.0.into()
}
}
#[automatically_derived]
impl sea_orm::TryGetable for StringVec {
fn try_get_by<I: sea_orm::ColIdx>(res: &QueryResult, idx: I) -> Result<Self, sea_orm::TryGetError> {
<Vec<String> as sea_orm::TryGetable>::try_get_by(res, idx).map(|v| StringVec(v))
}
}
#[automatically_derived]
impl sea_orm::sea_query::ValueType for StringVec {
fn try_from(v: Value) -> Result<Self, sea_orm::sea_query::ValueTypeErr> {
<Vec<String> as sea_orm::sea_query::ValueType>::try_from(v).map(|v| StringVec(v))
}
fn type_name() -> String {
stringify!(StringVec).to_owned()
}
fn array_type() -> sea_orm::sea_query::ArrayType {
sea_orm::sea_query::ArrayType::String
}
fn column_type() -> sea_orm::sea_query::ColumnType {
sea_orm::sea_query::ColumnType::String(StringLen::None)
}
}
#[automatically_derived]
impl sea_orm::sea_query::Nullable for Integer {
fn null() -> sea_orm::Value {
<Vec<String> as sea_orm::sea_query::Nullable>::null()
}
}
Wrapping Vec<T>
(backend generic)
You can also define a backend-generic Vec<T>
field by serialize / deserialize the object to / from JSON:
use sea_orm::entity::prelude::*;
use serde::{Deserialize, Serialize};
#[derive(Clone, Debug, PartialEq, Eq, DeriveEntityModel)]
#[sea_orm(table_name = "json_vec_type")]
pub struct Model {
#[sea_orm(primary_key)]
pub id: i32,
pub json_vec: ObjectVec,
}
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, FromJsonQueryResult)]
pub struct ObjectVec(pub Vec<MyObject>);
#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
pub struct MyObject {
..
}
Which ObjectVec
expands to:
impl sea_orm::TryGetableFromJson for ObjectVec {}
impl std::convert::From<ObjectVec> for sea_orm::Value {
fn from(source: ObjectVec) -> Self {
sea_orm::Value::Json(serde_json::to_value(&source).ok().map(|s| std::boxed::Box::new(s)))
}
}
impl sea_orm::sea_query::ValueType for ObjectVec {
fn try_from(v: sea_orm::Value) -> Result<Self, sea_orm::sea_query::ValueTypeErr> {
match v {
sea_orm::Value::Json(Some(json)) => Ok(
serde_json::from_value(*json).map_err(|_| sea_orm::sea_query::ValueTypeErr)?,
),
_ => Err(sea_orm::sea_query::ValueTypeErr),
}
}
fn type_name() -> String {
stringify!(ObjectVec).to_owned()
}
fn array_type() -> sea_orm::sea_query::ArrayType {
sea_orm::sea_query::ArrayType::Json
}
fn column_type() -> sea_orm::sea_query::ColumnType {
sea_orm::sea_query::ColumnType::Json
}
}
impl sea_orm::sea_query::Nullable for ObjectVec {
fn null() -> sea_orm::Value {
sea_orm::Value::Json(None)
}
}
Enum String
Since 1.1.8
, DeriveValueType
also supports enum
types. It offers a simpler alternative to DeriveActiveEnum
for client-side enums backed by string database types.
#[derive(DeriveValueType)]
#[sea_orm(value_type = "String")]
pub enum Tag {
Hard,
Soft,
}
// `from_str` defaults to `std::str::FromStr::from_str`
impl std::str::FromStr for Tag {
type Err = sea_orm::sea_query::ValueTypeErr;
fn from_str(s: &str) -> Result<Self, Self::Err> { .. }
}
// `to_str` defaults to `std::string::ToString::to_string`.
impl std::fmt::Display for Tag {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { .. }
}
Which Tag
expands to:
#[automatically_derived]
impl std::convert::From<Tag> for sea_orm::Value {
fn from(source: Tag) -> Self {
std::string::ToString::to_string(&source).into()
}
}
#[automatically_derived]
impl sea_orm::TryGetable for Tag {
fn try_get_by<I: sea_orm::ColIdx>(res: &sea_orm::QueryResult, idx: I)
-> std::result::Result<Self, sea_orm::TryGetError> {
let string = String::try_get_by(res, idx)?;
std::str::FromStr::from_str(&string).map_err(|err| sea_orm::TryGetError::DbErr(sea_orm::DbErr::Type(format!("{err:?}"))))
}
}
#[automatically_derived]
impl sea_orm::sea_query::ValueType for Tag {
fn try_from(v: sea_orm::Value) -> std::result::Result<Self, sea_orm::sea_query::ValueTypeErr> {
let string = <String as sea_orm::sea_query::ValueType>::try_from(v)?;
std::str::FromStr::from_str(&string).map_err(|_| sea_orm::sea_query::ValueTypeErr)
}
fn type_name() -> std::string::String {
stringify!(Tag).to_owned()
}
fn array_type() -> sea_orm::sea_query::ArrayType {
sea_orm::sea_query::ArrayType::String
}
fn column_type() -> sea_orm::sea_query::ColumnType {
sea_orm::sea_query::ColumnType::String(sea_orm::sea_query::StringLen::None)
}
}
#[automatically_derived]
impl sea_orm::sea_query::Nullable for Tag {
fn null() -> sea_orm::Value {
sea_orm::Value::String(None)
}
}
You can override from_str
and to_str
with custom functions, which is especially useful if you're using strum::Display
and strum::EnumString
, or manually implemented methods:
#[derive(DeriveValueType)]
#[sea_orm(value_type = "String", from_str = "Tag::from_str", to_str = "Tag::to_str")]
pub enum Tag {
Color,
Grey,
}
impl Tag {
fn from_str(s: &str) -> Result<Self, ValueTypeErr> { .. }
fn to_str(&self) -> &'static str { .. }
}