Trait FromQueryResult

pub trait FromQueryResult: Sized {
    // Required method
    fn from_query_result(res: &QueryResult, pre: &str) -> Result<Self, DbErr>;

    // Provided methods
    fn from_query_result_optional(
        res: &QueryResult,
        pre: &str,
    ) -> Result<Option<Self>, DbErr> { ... }
    fn from_query_result_nullable(
        res: &QueryResult,
        pre: &str,
    ) -> Result<Self, TryGetError> { ... }
    fn find_by_statement(stmt: Statement) -> SelectorRaw<SelectModel<Self>> { ... }
}

A Trait for implementing a QueryResult

Required Methods

fn from_query_result(res: &QueryResult, pre: &str) -> Result<Self, DbErr>

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:

fn from_query_result(res: &QueryResult, pre: &str) -> Result<Self, DbErr> {
    (Self::from_query_result_nullable(res, pre)?)
}

Provided Methods

fn from_query_result_optional( res: &QueryResult, pre: &str, ) -> Result<Option<Self>, DbErr>

Transform the error from instantiating a Model from a QueryResult and converting it to an Option

fn from_query_result_nullable( res: &QueryResult, pre: &str, ) -> Result<Self, TryGetError>

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 find_by_statement(stmt: Statement) -> SelectorRaw<SelectModel<Self>>

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,
    },]
);

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl FromQueryResult for Model

fn from_query_result(row: &QueryResult, pre: &str) -> Result<Model, DbErr>

impl<T> FromQueryResult for Option<T>

where T: FromQueryResult,

fn from_query_result(res: &QueryResult, pre: &str) -> Result<Option<T>, DbErr>

fn from_query_result_optional( res: &QueryResult, pre: &str, ) -> Result<Option<Option<T>>, DbErr>

fn from_query_result_nullable( res: &QueryResult, pre: &str, ) -> Result<Option<T>, TryGetError>

Implementors

impl FromQueryResult for Value