feat: add sqlx::Done and return from Executor::execute()

+ Done::rows_affected()

 + Done::last_insert_id()

sqlx-core/src/postgres/connection/executor.rs

@@ -12,7 +12,7 @@ use crate::postgres::message::{
     Query, RowDescription,
 };
 use crate::postgres::type_info::PgType;
-use crate::postgres::{PgArguments, PgConnection, PgRow, PgValueFormat, Postgres};
+use crate::postgres::{PgArguments, PgConnection, PgDone, PgRow, PgValueFormat, Postgres};
 use crate::statement::StatementInfo;
 
 async fn prepare(
@@ -142,7 +142,7 @@ impl PgConnection {
         query: &str,
         arguments: Option<PgArguments>,
         limit: u8,
-    ) -> Result<impl Stream<Item = Result<Either<u64, PgRow>, Error>> + '_, Error> {
+    ) -> Result<impl Stream<Item = Result<Either<PgDone, PgRow>, Error>> + '_, Error> {
         // before we continue, wait until we are "ready" to accept more queries
         self.wait_until_ready().await?;
 
@@ -219,7 +219,9 @@ impl PgConnection {
                         // a SQL command completed normally
                         let cc: CommandComplete = message.decode()?;
 
-                        r#yield!(Either::Left(cc.rows_affected()));
+                        r#yield!(Either::Left(PgDone {
+                            rows_affected: cc.rows_affected(),
+                        }));
                     }
 
                     MessageFormat::EmptyQueryResponse => {
@@ -272,7 +274,7 @@ impl<'c> Executor<'c> for &'c mut PgConnection {
     fn fetch_many<'e, 'q: 'e, E: 'q>(
         self,
         mut query: E,
-    ) -> BoxStream<'e, Result<Either<u64, PgRow>, Error>>
+    ) -> BoxStream<'e, Result<Either<PgDone, PgRow>, Error>>
     where
         'c: 'e,
         E: Execute<'q, Self::Database>,

sqlx-core/src/postgres/database.rs

@@ -2,7 +2,7 @@ use crate::database::{Database, HasArguments, HasStatementCache, HasValueRef};
 use crate::postgres::arguments::PgArgumentBuffer;
 use crate::postgres::value::{PgValue, PgValueRef};
 use crate::postgres::{
-    PgArguments, PgColumn, PgConnection, PgRow, PgTransactionManager, PgTypeInfo,
+    PgArguments, PgColumn, PgConnection, PgDone, PgRow, PgTransactionManager, PgTypeInfo,
 };
 
 /// PostgreSQL database driver.
@@ -16,6 +16,8 @@ impl Database for Postgres {
 
     type Row = PgRow;
 
+    type Done = PgDone;
+
     type Column = PgColumn;
 
     type TypeInfo = PgTypeInfo;

sqlx-core/src/postgres/done.rs

@@ -0,0 +1,24 @@
+use crate::done::Done;
+use crate::postgres::Postgres;
+use std::iter::{Extend, IntoIterator};
+
+#[derive(Debug, Default)]
+pub struct PgDone {
+    pub(super) rows_affected: u64,
+}
+
+impl Done for PgDone {
+    type Database = Postgres;
+
+    fn rows_affected(&self) -> u64 {
+        self.rows_affected
+    }
+}
+
+impl Extend<PgDone> for PgDone {
+    fn extend<T: IntoIterator<Item = PgDone>>(&mut self, iter: T) {
+        for elem in iter {
+            self.rows_affected += elem.rows_affected;
+        }
+    }
+}

sqlx-core/src/postgres/listener.rs

@@ -3,7 +3,7 @@ use crate::executor::{Execute, Executor};
 use crate::pool::PoolOptions;
 use crate::pool::{Pool, PoolConnection};
 use crate::postgres::message::{MessageFormat, Notification};
-use crate::postgres::{PgConnection, PgRow, Postgres};
+use crate::postgres::{PgConnection, PgDone, PgRow, Postgres};
 use crate::statement::StatementInfo;
 use either::Either;
 use futures_channel::mpsc;
@@ -197,7 +197,7 @@ impl<'c> Executor<'c> for &'c mut PgListener {
     fn fetch_many<'e, 'q: 'e, E: 'q>(
         self,
         query: E,
-    ) -> BoxStream<'e, Result<Either<u64, PgRow>, Error>>
+    ) -> BoxStream<'e, Result<Either<PgDone, PgRow>, Error>>
     where
         'c: 'e,
         E: Execute<'q, Self::Database>,

sqlx-core/src/postgres/mod.rs

@@ -4,6 +4,7 @@ mod arguments;
 mod column;
 mod connection;
 mod database;
+mod done;
 mod error;
 mod io;
 mod listener;
@@ -22,6 +23,7 @@ pub use arguments::{PgArgumentBuffer, PgArguments};
 pub use column::PgColumn;
 pub use connection::PgConnection;
 pub use database::Postgres;
+pub use done::PgDone;
 pub use error::{PgDatabaseError, PgErrorPosition};
 pub use listener::{PgListener, PgNotification};
 pub use message::PgSeverity;