feat(postgres): allow running multiple statements in no tx migrations

sqlx-postgres/src/migrate.rs

@@ -276,10 +276,19 @@ async fn execute_migration(
     conn: &mut PgConnection,
     migration: &Migration,
 ) -> Result<(), MigrateError> {
-    let _ = conn
-        .execute(&*migration.sql)
-        .await
-        .map_err(|e| MigrateError::ExecuteMigration(e, migration.version))?;
+    let sql = migration.sql.trim();
+    // note: this would _not_ match the split if the file starts with `-- split-migration`
+    // because it requires a new line prefix, but that doesn't really make sense anyway so it's fine
+    let split_migrations = sql.split("\n-- split-migration\n");
+    for part in split_migrations {
+        if part.trim().is_empty() {
+            continue;
+        }
+        let _ = conn
+            .execute(&*part.trim())
+            .await
+            .map_err(|e| MigrateError::ExecuteMigration(e, migration.version))?;
+    }
 
     // language=SQL
     let _ = query(

tests/postgres/migrate.rs

@@ -85,6 +85,26 @@ async fn no_tx(mut conn: PoolConnection<Postgres>) -> anyhow::Result<()> {
     Ok(())
 }
 
+
+#[sqlx::test(migrations = false)]
+async fn split(mut conn: PoolConnection<Postgres>) -> anyhow::Result<()> {
+    clean_up(&mut conn).await?;
+    let migrator = Migrator::new(Path::new("tests/postgres/migrations_split")).await?;
+
+    // run migration
+    migrator.run(&mut conn).await?;
+
+    // check outcome
+    let res: i32 = conn
+        .fetch_one("SELECT * FROM test_table")
+        .await?
+        .get(0);
+
+    assert_eq!(res, 1);
+
+    Ok(())
+}
+
 /// Ensure that we have a clean initial state.
 async fn clean_up(conn: &mut PgConnection) -> anyhow::Result<()> {
     conn.execute("DROP DATABASE IF EXISTS test_db").await.ok();

tests/postgres/migrations_split/0_create_index.sql

@@ -0,0 +1,8 @@
+-- no-transaction
+
+CREATE TABLE test_table (x int);
+-- split-migration
+CREATE INDEX CONCURRENTLY test_table_x_idx ON test_table (x);
+-- split-migration
+INSERT INTO test_table (x) VALUES (1);
+-- prove that you can have a comment that won't split -- split-migration DROP TABLE does_not_exist;