Trait FromQueryResult

Source

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>> { ... }
}

Expand description

A Trait for implementing a QueryResult

Required Methods§

Source

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§

Source

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

Source

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!

Source

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

use sea_orm::{FromQueryResult, query::*};

#[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)
?;

assert_eq!(
    res,
    [SelectResult {
        name: "Chocolate Forest".to_owned(),
        num_of_cakes: 2,
    },]
);