Refactor and add stream() to SelectorRaw

src/executor/select.rs

@@ -416,18 +416,25 @@ where
         }
     }
 
+    fn into_selector_raw<'a, C>(self, db: &C) -> SelectorRaw<S>
+    where
+        C: ConnectionTrait<'a>,
+    {
+        let builder = db.get_database_backend();
+        let stmt = builder.build(&self.query);
+        SelectorRaw {
+            stmt,
+            selector: self.selector,
+        }
+    }
+
     /// Get a Model from a Select operation
     pub async fn one<'a, C>(mut self, db: &C) -> Result<Option<S::Item>, DbErr>
     where
         C: ConnectionTrait<'a>,
     {
-        let builder = db.get_database_backend();
         self.query.limit(1);
-        let row = db.query_one(builder.build(&self.query)).await?;
+        self.into_selector_raw(db).one(db).await
-        match row {
-            Some(row) => Ok(Some(S::from_raw_query_result(row)?)),
-            None => Ok(None),
-        }
     }
 
     /// Get all results from a Select operation
@@ -435,16 +442,10 @@ where
     where
         C: ConnectionTrait<'a>,
     {
-        let builder = db.get_database_backend();
+        self.into_selector_raw(db).all(db).await
-        let rows = db.query_all(builder.build(&self.query)).await?;
-        let mut models = Vec::new();
-        for row in rows.into_iter() {
-            models.push(S::from_raw_query_result(row)?);
-        }
-        Ok(models)
     }
 
-    /// Stream the results of the operation
+    /// Stream the results of the Select operation
     pub async fn stream<'a: 'b, 'b, C>(
         self,
         db: &'a C,
@@ -453,11 +454,7 @@ where
         C: ConnectionTrait<'a>,
         S: 'b,
     {
-        let builder = db.get_database_backend();
+        self.into_selector_raw(db).stream(db).await
-        let stream = db.stream(builder.build(&self.query)).await?;
-        Ok(Box::pin(stream.and_then(|row| {
-            futures::future::ready(S::from_raw_query_result(row))
-        })))
     }
 }
 
@@ -465,8 +462,7 @@ impl<S> SelectorRaw<S>
 where
     S: SelectorTrait,
 {
-    /// Create `SelectorRaw` from Statment. Executing this `SelectorRaw` will
+    /// Select a custom Model from a raw SQL [Statement].
-    /// return a type `M` which implement `FromQueryResult`.
     pub fn from_statement<M>(stmt: Statement) -> SelectorRaw<SelectModel<M>>
     where
         M: FromQueryResult,
@@ -629,6 +625,7 @@ where
         }
     }
 
+    /// Get a Model from a Select operation
     /// ```
     /// # #[cfg(feature = "mock")]
     /// # use sea_orm::{error::*, tests_cfg::*, MockDatabase, Transaction, DbBackend};
@@ -671,6 +668,7 @@ where
         }
     }
 
+    /// Get all results from a Select operation
     /// ```
     /// # #[cfg(feature = "mock")]
     /// # use sea_orm::{error::*, tests_cfg::*, MockDatabase, Transaction, DbBackend};
@@ -713,6 +711,21 @@ where
         }
         Ok(models)
     }
+
+    /// Stream the results of the Select operation
+    pub async fn stream<'a: 'b, 'b, C>(
+        self,
+        db: &'a C,
+    ) -> Result<Pin<Box<dyn Stream<Item = Result<S::Item, DbErr>> + 'b>>, DbErr>
+    where
+        C: ConnectionTrait<'a>,
+        S: 'b,
+    {
+        let stream = db.stream(self.stmt).await?;
+        Ok(Box::pin(stream.and_then(|row| {
+            futures::future::ready(S::from_raw_query_result(row))
+        })))
+    }
 }
 
 fn consolidate_query_result<L, R>(