Returning support for SQLite

src/database/db_connection.rs

@@ -228,9 +228,9 @@ impl<'a> ConnectionTrait<'a> for DatabaseConnection {
                 true
             }
             #[cfg(feature = "sqlx-sqlite")]
-            DatabaseConnection::SqlxSqlitePoolConnection(_) => {
+            DatabaseConnection::SqlxSqlitePoolConnection(conn) => {
                 // Supported by SQLite on or after version 3.35.0 (2021-03-12)
-                false
+                conn.support_returning
             }
             #[cfg(feature = "mock")]
             DatabaseConnection::MockDatabaseConnection(conn) => match conn.get_database_backend() {
@@ -255,9 +255,9 @@ impl<'a> ConnectionTrait<'a> for DatabaseConnection {
                 true
             }
             #[cfg(feature = "sqlx-sqlite")]
-            DatabaseConnection::SqlxSqlitePoolConnection(_) => {
+            DatabaseConnection::SqlxSqlitePoolConnection(conn) => {
                 // Supported by SQLite on or after version 3.35.0 (2021-03-12)
-                false
+                conn.support_returning
             }
             #[cfg(feature = "mock")]
             DatabaseConnection::MockDatabaseConnection(conn) => match conn.get_database_backend() {
@@ -301,7 +301,7 @@ impl DatabaseConnection {
             #[cfg(feature = "sqlx-postgres")]
             DatabaseConnection::SqlxPostgresPoolConnection(_) => "".to_string(),
             #[cfg(feature = "sqlx-sqlite")]
-            DatabaseConnection::SqlxSqlitePoolConnection(_) => "".to_string(),
+            DatabaseConnection::SqlxSqlitePoolConnection(conn) => conn.version.to_string(),
             DatabaseConnection::Disconnected => panic!("Disconnected"),
             _ => unimplemented!(),
         }

src/database/transaction.rs

@@ -54,11 +54,12 @@ impl DatabaseTransaction {
     #[cfg(feature = "sqlx-sqlite")]
     pub(crate) async fn new_sqlite(
         inner: PoolConnection<sqlx::Sqlite>,
+        support_returning: bool,
     ) -> Result<DatabaseTransaction, DbErr> {
         Self::begin(
             Arc::new(Mutex::new(InnerConnection::Sqlite(inner))),
             DbBackend::Sqlite,
-            false,
+            support_returning,
         )
         .await
     }
@@ -378,7 +379,7 @@ impl<'a> ConnectionTrait<'a> for DatabaseTransaction {
             }
             DbBackend::Sqlite => {
                 // Supported by SQLite on or after version 3.35.0 (2021-03-12)
-                false
+                self.support_returning
             }
         }
     }
@@ -395,7 +396,7 @@ impl<'a> ConnectionTrait<'a> for DatabaseTransaction {
             }
             DbBackend::Sqlite => {
                 // Supported by SQLite on or after version 3.35.0 (2021-03-12)
-                false
+                self.support_returning
             }
         }
     }

src/driver/sqlx_sqlite.rs

@@ -1,8 +1,9 @@
+use regex::Regex;
 use std::{future::Future, pin::Pin};
 
 use sqlx::{
     sqlite::{SqliteArguments, SqliteConnectOptions, SqliteQueryResult, SqliteRow},
-    Sqlite, SqlitePool,
+    Row, Sqlite, SqlitePool,
 };
 
 sea_query::sea_query_driver_sqlite!();
@@ -10,7 +11,7 @@ use sea_query_driver_sqlite::bind_query;
 
 use crate::{
     debug_print, error::*, executor::*, ConnectOptions, DatabaseConnection, DatabaseTransaction,
-    QueryStream, Statement, TransactionError,
+    DbBackend, QueryStream, Statement, TransactionError,
 };
 
 use super::sqlx_common::*;
@@ -23,6 +24,8 @@ pub struct SqlxSqliteConnector;
 #[derive(Debug, Clone)]
 pub struct SqlxSqlitePoolConnection {
     pool: SqlitePool,
+    pub(crate) version: String,
+    pub(crate) support_returning: bool,
 }
 
 impl SqlxSqliteConnector {
@@ -46,9 +49,7 @@ impl SqlxSqliteConnector {
             options.max_connections(1);
         }
         if let Ok(pool) = options.pool_options().connect_with(opt).await {
-            Ok(DatabaseConnection::SqlxSqlitePoolConnection(
-                SqlxSqlitePoolConnection { pool },
-            ))
+            into_db_connection(pool).await
         } else {
             Err(DbErr::Conn("Failed to connect.".to_owned()))
         }
@@ -57,8 +58,8 @@ impl SqlxSqliteConnector {
 
 impl SqlxSqliteConnector {
     /// Instantiate a sqlx pool connection to a [DatabaseConnection]
-    pub fn from_sqlx_sqlite_pool(pool: SqlitePool) -> DatabaseConnection {
-        DatabaseConnection::SqlxSqlitePoolConnection(SqlxSqlitePoolConnection { pool })
+    pub async fn from_sqlx_sqlite_pool(pool: SqlitePool) -> Result<DatabaseConnection, DbErr> {
+        into_db_connection(pool).await
     }
 }
 
@@ -133,7 +134,7 @@ impl SqlxSqlitePoolConnection {
     /// Bundle a set of SQL statements that execute together.
     pub async fn begin(&self) -> Result<DatabaseTransaction, DbErr> {
         if let Ok(conn) = self.pool.acquire().await {
-            DatabaseTransaction::new_sqlite(conn).await
+            DatabaseTransaction::new_sqlite(conn, self.support_returning).await
         } else {
             Err(DbErr::Query(
                 "Failed to acquire connection from pool.".to_owned(),
@@ -152,7 +153,7 @@ impl SqlxSqlitePoolConnection {
         E: std::error::Error + Send,
     {
         if let Ok(conn) = self.pool.acquire().await {
-            let transaction = DatabaseTransaction::new_sqlite(conn)
+            let transaction = DatabaseTransaction::new_sqlite(conn, self.support_returning)
                 .await
                 .map_err(|e| TransactionError::Connection(e))?;
             transaction.run(callback).await
@@ -187,3 +188,44 @@ pub(crate) fn sqlx_query(stmt: &Statement) -> sqlx::query::Query<'_, Sqlite, Sql
     }
     query
 }
+
+async fn into_db_connection(pool: SqlitePool) -> Result<DatabaseConnection, DbErr> {
+    let (version, support_returning) = parse_support_returning(&pool).await?;
+    Ok(DatabaseConnection::SqlxSqlitePoolConnection(
+        SqlxSqlitePoolConnection {
+            pool,
+            version,
+            support_returning,
+        },
+    ))
+}
+
+async fn parse_support_returning(pool: &SqlitePool) -> Result<(String, bool), DbErr> {
+    let stmt = Statement::from_string(
+        DbBackend::Sqlite,
+        r#"SELECT sqlite_version() AS version"#.to_owned(),
+    );
+    let query = sqlx_query(&stmt);
+    let row = query
+        .fetch_one(pool)
+        .await
+        .map_err(sqlx_error_to_query_err)?;
+    let version: String = row.try_get("version").map_err(sqlx_error_to_query_err)?;
+    let regex = Regex::new(r"^(\d+)?.(\d+)?.(\*|\d+)").unwrap();
+    let captures = regex.captures(&version).unwrap();
+    macro_rules! parse_captures {
+        ( $idx: expr ) => {
+            captures.get($idx).map_or(0, |m| {
+                m.as_str()
+                    .parse::<usize>()
+                    .map_err(|e| DbErr::Conn(e.to_string()))
+                    .unwrap()
+            })
+        };
+    }
+    let ver_major = parse_captures!(1);
+    let ver_minor = parse_captures!(2);
+    // Supported if it's version 3.35.0 (2021-03-12) or after
+    let support_returning = ver_major >= 3 && ver_minor >= 35;
+    Ok((version, support_returning))
+}

tests/returning_tests.rs

@@ -34,17 +34,12 @@ async fn main() -> Result<(), DbErr> {
 
     let mut returning = Query::select();
     returning.columns(vec![Column::Id, Column::Name, Column::ProfitMargin]);
-    if db.returning_on_insert() {
-        insert.returning(returning.clone());
-    }
-    if db.returning_on_update() {
-        update.returning(returning.clone());
-    }
 
     create_tables(db).await?;
     println!("db_version: {:#?}", db.version());
 
     if db.returning_on_insert() {
+        insert.returning(returning.clone());
         let insert_res = db
             .query_one(builder.build(&insert))
             .await?
@@ -57,6 +52,7 @@ async fn main() -> Result<(), DbErr> {
         assert!(insert_res.rows_affected() > 0);
     }
     if db.returning_on_update() {
+        update.returning(returning.clone());
         let update_res = db
             .query_one(builder.build(&update))
             .await?