Improve API

examples/bakery.sql

@@ -6,11 +6,20 @@ CREATE TABLE `cake` (
   PRIMARY KEY (`id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
 
+INSERT INTO `cake` (`id`, `name`) VALUES
+	(1, 'New York Cheese'),
+	(2, 'Chocolate Fudge');
+
 DROP TABLE IF EXISTS `fruit`;
 
 CREATE TABLE `fruit` (
   `id` int NOT NULL AUTO_INCREMENT,
   `name` varchar(255) DEFAULT NULL,
-  `cake_id` int,
+  `cake_id` int DEFAULT NULL,
   PRIMARY KEY (`id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+
+INSERT INTO `fruit` (`id`, `name`, `cake_id`) VALUES
+	(1, 'Blueberry', 1),
+	(2, 'Rasberry', 1),
+	(3, 'Strawberry', 2);

examples/sqlx-mysql/src/example_fruit.rs

@@ -117,7 +117,6 @@ impl IdenStatic for Column {
     }
 }
 
-
 // TODO: implement with derive macro
 impl Iden for PrimaryKey {
     fn unquoted(&self, s: &mut dyn std::fmt::Write) {

examples/sqlx-mysql/src/main.rs

@@ -15,7 +15,7 @@ async fn main() {
     println!("{:?}", db);
     println!();
 
-    println!("find all");
+    print!("find all: ");
 
     let cakes = cake::Entity::find().all(&db).await.unwrap();
 
@@ -25,15 +25,23 @@ async fn main() {
         println!();
     }
 
-    println!("find one by primary key");
+    let fruits = fruit::Entity::find().all(&db).await.unwrap();
 
-    let cheese = cake::Entity::find_one(&db, 1).await.unwrap();
+    println!();
+    for cc in fruits.iter() {
+        println!("{:?}", cc);
+        println!();
+    }
+
+    print!("find one by primary key: ");
+
+    let cheese = cake::Entity::find_by(1).one(&db).await.unwrap();
 
     println!();
     println!("{:?}", cheese);
     println!();
 
-    println!("find models belongs to");
+    print!("find models belong to: ");
 
     let fruits = cheese.find_fruit().all(&db).await.unwrap();
 

src/connector/select.rs

@@ -4,8 +4,9 @@ impl<E: 'static> Select<E>
 where
     E: EntityTrait,
 {
-    pub async fn one(self, db: &Database) -> Result<E::Model, QueryErr> {
+    pub async fn one(mut self, db: &Database) -> Result<E::Model, QueryErr> {
         let builder = db.get_query_builder_backend();
+        self.query().limit(1);
         let row = db.get_connection().query_one(self.build(builder)).await?;
         Ok(<E as EntityTrait>::Model::from_query_result(row)?)
     }

src/entity/base.rs

@@ -1,6 +1,5 @@
 use crate::{
-    ColumnTrait, Connection, Database, ModelTrait, PrimaryKeyTrait, QueryErr, RelationBuilder,
-    RelationTrait, RelationType, Select,
+    ColumnTrait, ModelTrait, PrimaryKeyTrait, RelationBuilder, RelationTrait, RelationType, Select,
 };
 use async_trait::async_trait;
 use sea_query::{Expr, Iden, IntoIden, Value};
@@ -41,13 +40,6 @@ pub trait EntityTrait: EntityName {
         RelationBuilder::new(RelationType::HasMany, Self::default(), entity)
     }
 
-    fn belongs_to<E>(entity: E) -> RelationBuilder
-    where
-        E: IntoIden,
-    {
-        RelationBuilder::new(RelationType::BelongsTo, Self::default(), entity)
-    }
-
     /// ```
     /// use sea_orm::{ColumnTrait, EntityTrait, tests_cfg::cake, sea_query::MysqlQueryBuilder};
     ///
@@ -62,12 +54,21 @@ pub trait EntityTrait: EntityName {
         Select::<Self>::new()
     }
 
-    async fn find_one<V>(db: &Database, v: V) -> Result<Self::Model, QueryErr>
+    /// Find a model by primary key
+    /// ```
+    /// use sea_orm::{ColumnTrait, EntityTrait, tests_cfg::cake, sea_query::MysqlQueryBuilder};
+    ///
+    /// assert_eq!(
+    ///     cake::Entity::find_by(11)
+    ///         .build(MysqlQueryBuilder)
+    ///         .to_string(),
+    ///     "SELECT `cake`.`id`, `cake`.`name` FROM `cake` WHERE `cake`.`id` = 11"
+    /// );
+    /// ```
+    fn find_by<V>(v: V) -> Select<Self>
     where
-        V: Into<Value> + Send,
+        V: Into<Value>,
     {
-        let builder = db.get_query_builder_backend();
-        let stmt = {
         let mut select = Self::find();
         if let Some(key) = Self::PrimaryKey::iter().next() {
             // TODO: supporting composite primary key
@@ -75,9 +76,6 @@ pub trait EntityTrait: EntityName {
         } else {
             panic!("undefined primary key");
         }
-            select.build(builder)
-        };
-        let row = db.get_connection().query_one(stmt).await?;
-        Ok(Self::Model::from_query_result(row)?)
+        select
     }
 }

src/entity/column.rs

@@ -31,6 +31,17 @@ pub trait ColumnTrait: IdenStatic {
     bind_oper!(lt);
     bind_oper!(lte);
 
+    /// ```
+    /// use sea_orm::{ColumnTrait, EntityTrait, tests_cfg::cake, sea_query::MysqlQueryBuilder};
+    ///
+    /// assert_eq!(
+    ///     cake::Entity::find()
+    ///         .filter(cake::Column::Id.between(2,3))
+    ///         .build(MysqlQueryBuilder)
+    ///         .to_string(),
+    ///     "SELECT `cake`.`id`, `cake`.`name` FROM `cake` WHERE `cake`.`id` BETWEEN 2 AND 3"
+    /// );
+    /// ```
     fn between<V>(&self, a: V, b: V) -> SimpleExpr
     where
         V: Into<Value>,
@@ -38,6 +49,17 @@ pub trait ColumnTrait: IdenStatic {
         Expr::tbl(self.as_iden(), *self).between(a, b)
     }
 
+    /// ```
+    /// use sea_orm::{ColumnTrait, EntityTrait, tests_cfg::cake, sea_query::MysqlQueryBuilder};
+    ///
+    /// assert_eq!(
+    ///     cake::Entity::find()
+    ///         .filter(cake::Column::Id.not_between(2,3))
+    ///         .build(MysqlQueryBuilder)
+    ///         .to_string(),
+    ///     "SELECT `cake`.`id`, `cake`.`name` FROM `cake` WHERE `cake`.`id` NOT BETWEEN 2 AND 3"
+    /// );
+    /// ```
     fn not_between<V>(&self, a: V, b: V) -> SimpleExpr
     where
         V: Into<Value>,

src/entity/relation.rs

@@ -7,7 +7,6 @@ use std::rc::Rc;
 pub enum RelationType {
     HasOne,
     HasMany,
-    BelongsTo,
 }
 
 pub trait RelationTrait: Debug + 'static {

src/query/select.rs

@@ -8,7 +8,7 @@ pub use sea_query::JoinType;
 use sea_query::{Expr, Iden, IntoIden, Order, QueryBuilder, SelectStatement, SimpleExpr};
 use std::rc::Rc;
 
-#[derive(Debug)]
+#[derive(Clone, Debug)]
 pub struct Select<E: 'static>
 where
     E: EntityTrait,

src/tests_cfg/fruit.rs

@@ -117,7 +117,6 @@ impl IdenStatic for Column {
     }
 }
 
-
 // TODO: implement with derive macro
 impl Iden for PrimaryKey {
     fn unquoted(&self, s: &mut dyn std::fmt::Write) {