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use crate::{
find_linked_recursive, ActiveModelBehavior, ActiveModelTrait, ConnectionTrait, DbErr,
DeleteResult, EntityTrait, IntoActiveModel, Linked, QueryFilter, QueryResult, Related, Select,
SelectModel, SelectorRaw, Statement, TryGetError,
};
use async_trait::async_trait;
pub use sea_query::Value;
use std::fmt::Debug;
/// The interface for Model, implemented by data structs
#[async_trait]
pub trait ModelTrait: Clone + Send + Debug {
#[allow(missing_docs)]
type Entity: EntityTrait;
/// Get the [Value] of a column from an Entity
fn get(&self, c: <Self::Entity as EntityTrait>::Column) -> Value;
/// Set the [Value] of a column in an Entity
fn set(&mut self, c: <Self::Entity as EntityTrait>::Column, v: Value);
/// Find related Models
fn find_related<R>(&self, _: R) -> Select<R>
where
R: EntityTrait,
Self::Entity: Related<R>,
{
<Self::Entity as Related<R>>::find_related().belongs_to(self)
}
/// Find linked Models
fn find_linked<L>(&self, l: L) -> Select<L::ToEntity>
where
L: Linked<FromEntity = Self::Entity>,
{
let tbl_alias = &format!("r{}", l.link().len() - 1);
l.find_linked().belongs_to_tbl_alias(self, tbl_alias)
}
#[doc(hidden)]
/// Find linked Models with a recursive CTE for self-referencing relation chains
fn find_linked_recursive<L>(&self, l: L) -> Select<L::ToEntity>
where
L: Linked<FromEntity = Self::Entity, ToEntity = Self::Entity>,
{
// Have to do this because L is not Clone
let link = l.link();
let initial_query = self.find_linked(l);
find_linked_recursive(initial_query, link)
}
/// Delete a model
async fn delete<'a, A, C>(self, db: &'a C) -> Result<DeleteResult, DbErr>
where
Self: IntoActiveModel<A>,
C: ConnectionTrait,
A: ActiveModelTrait<Entity = Self::Entity> + ActiveModelBehavior + Send + 'a,
{
self.into_active_model().delete(db).await
}
}
/// A Trait for implementing a [QueryResult]
pub trait FromQueryResult: Sized {
/// Instantiate a Model from a [QueryResult]
///
/// NOTE: Please also override `from_query_result_nullable` when manually implementing.
/// The future default implementation will be along the lines of:
///
/// ```rust,ignore
/// fn from_query_result(res: &QueryResult, pre: &str) -> Result<Self, DbErr> {
/// (Self::from_query_result_nullable(res, pre)?)
/// }
/// ```
fn from_query_result(res: &QueryResult, pre: &str) -> Result<Self, DbErr>;
/// Transform the error from instantiating a Model from a [QueryResult]
/// and converting it to an [Option]
fn from_query_result_optional(res: &QueryResult, pre: &str) -> Result<Option<Self>, DbErr> {
Ok(Self::from_query_result(res, pre).ok())
// would really like to do the following, but can't without version bump:
// match Self::from_query_result_nullable(res, pre) {
// Ok(v) => Ok(Some(v)),
// Err(TryGetError::Null(_)) => Ok(None),
// Err(TryGetError::DbErr(err)) => Err(err),
// }
}
/// Transform the error from instantiating a Model from a [QueryResult]
/// and converting it to an [Option]
///
/// NOTE: This will most likely stop being a provided method in the next major version!
fn from_query_result_nullable(res: &QueryResult, pre: &str) -> Result<Self, TryGetError> {
Self::from_query_result(res, pre).map_err(TryGetError::DbErr)
}
/// ```
/// # use sea_orm::{error::*, tests_cfg::*, *};
/// #
/// # #[smol_potat::main]
/// # #[cfg(feature = "mock")]
/// # pub async fn main() -> Result<(), DbErr> {
/// #
/// # let db = MockDatabase::new(DbBackend::Postgres)
/// # .append_query_results([[
/// # maplit::btreemap! {
/// # "name" => Into::<Value>::into("Chocolate Forest"),
/// # "num_of_cakes" => Into::<Value>::into(2),
/// # },
/// # ]])
/// # .into_connection();
/// #
/// use sea_orm::{query::*, FromQueryResult};
///
/// #[derive(Debug, PartialEq, FromQueryResult)]
/// struct SelectResult {
/// name: String,
/// num_of_cakes: i32,
/// }
///
/// let res: Vec<SelectResult> = SelectResult::find_by_statement(Statement::from_sql_and_values(
/// DbBackend::Postgres,
/// r#"SELECT "name", COUNT(*) AS "num_of_cakes" FROM "cake" GROUP BY("name")"#,
/// [],
/// ))
/// .all(&db)
/// .await?;
///
/// assert_eq!(
/// res,
/// [SelectResult {
/// name: "Chocolate Forest".to_owned(),
/// num_of_cakes: 2,
/// },]
/// );
/// #
/// # assert_eq!(
/// # db.into_transaction_log(),
/// # [Transaction::from_sql_and_values(
/// # DbBackend::Postgres,
/// # r#"SELECT "name", COUNT(*) AS "num_of_cakes" FROM "cake" GROUP BY("name")"#,
/// # []
/// # ),]
/// # );
/// #
/// # Ok(())
/// # }
/// ```
fn find_by_statement(stmt: Statement) -> SelectorRaw<SelectModel<Self>> {
SelectorRaw::<SelectModel<Self>>::from_statement(stmt)
}
}
impl<T: FromQueryResult> FromQueryResult for Option<T> {
fn from_query_result(res: &QueryResult, pre: &str) -> Result<Self, DbErr> {
Ok(Self::from_query_result_nullable(res, pre)?)
}
fn from_query_result_optional(res: &QueryResult, pre: &str) -> Result<Option<Self>, DbErr> {
match Self::from_query_result_nullable(res, pre) {
Ok(v) => Ok(Some(v)),
Err(TryGetError::Null(_)) => Ok(None),
Err(TryGetError::DbErr(err)) => Err(err),
}
}
fn from_query_result_nullable(res: &QueryResult, pre: &str) -> Result<Self, TryGetError> {
match T::from_query_result_nullable(res, pre) {
Ok(v) => Ok(Some(v)),
Err(TryGetError::Null(_)) => Ok(None),
Err(err @ TryGetError::DbErr(_)) => Err(err),
}
}
}
/// A Trait for any type that can be converted into an Model
pub trait TryIntoModel<M>
where
M: ModelTrait,
{
/// Method to call to perform the conversion
fn try_into_model(self) -> Result<M, DbErr>;
}
impl<M> TryIntoModel<M> for M
where
M: ModelTrait,
{
fn try_into_model(self) -> Result<M, DbErr> {
Ok(self)
}
}