Add support for MySQL savepoints

Author: JanJakes

tests/WP_SQLite_Driver_Tests.php

@@ -6294,4 +6294,38 @@ public function testLockTemporaryTables(): void {
 		$this->assertQuery( 'LOCK TABLES t1 READ, t2 READ, t3 WRITE' );
 		$this->assertQuery( 'UNLOCK TABLES' );
 	}
+
+	public function testTransactionSavepoints(): void {
+		$this->assertQuery( 'CREATE TABLE t (id INT)' );
+
+		$this->assertQuery( 'BEGIN' );
+		$this->assertQuery( 'INSERT INTO t (id) VALUES (1)' );
+		$result = $this->assertQuery( 'SELECT * FROM t' );
+		$this->assertSame( array( '1' ), (array) array_column( $result, 'id' ) );
+
+		$this->assertQuery( 'SAVEPOINT sp1' );
+		$this->assertQuery( 'INSERT INTO t (id) VALUES (2)' );
+		$result = $this->assertQuery( 'SELECT * FROM t' );
+		$this->assertSame( array( '1', '2' ), (array) array_column( $result, 'id' ) );
+
+		$this->assertQuery( 'SAVEPOINT sp2' );
+		$this->assertQuery( 'INSERT INTO t (id) VALUES (3)' );
+		$result = $this->assertQuery( 'SELECT * FROM t' );
+		$this->assertSame( array( '1', '2', '3' ), (array) array_column( $result, 'id' ) );
+
+		$this->assertQuery( 'ROLLBACK TO SAVEPOINT sp1' );
+		$result = $this->assertQuery( 'SELECT * FROM t' );
+		$this->assertSame( array( '1' ), (array) array_column( $result, 'id' ) );
+
+		$this->assertQuery( 'RELEASE SAVEPOINT sp1' );
+		$this->assertQuery( 'ROLLBACK' );
+		$result = $this->assertQuery( 'SELECT * FROM t' );
+		$this->assertSame( array(), (array) array_column( $result, 'id' ) );
+	}
+
+	public function testRollbackNonExistentTransactionSavepoint(): void {
+		$this->expectException( 'WP_SQLite_Driver_Exception' );
+		$this->expectExceptionMessage( 'no such savepoint: sp1' );
+		$this->assertQuery( 'ROLLBACK TO SAVEPOINT sp1' );
+	}
 }

wp-includes/sqlite-ast/class-wp-sqlite-driver.php

@@ -1033,9 +1033,27 @@ private function execute_transaction_or_locking_statement( WP_Parser_Node $node
 
 				// Unknown statement. Fall through to the default case.
 			case 'savepointStatement':
-				// ROLLBACK.
+				$savepoint_name = $this->translate( $subnode->get_first_child_node( 'identifier' ) );
+
+				// ROLLBACK/ROLLBACK TO SAVEPOINT <identifier>.
 				if ( WP_MySQL_Lexer::ROLLBACK_SYMBOL === $token->id ) {
-					$this->rollback();
+					if ( null === $savepoint_name ) {
+						$this->rollback();
+					} else {
+						$this->execute_sqlite_query( sprintf( 'ROLLBACK TO SAVEPOINT %s', $savepoint_name ) );
+					}
+					break;
+				}
+
+				// SAVEPOINT.
+				if ( WP_MySQL_Lexer::SAVEPOINT_SYMBOL === $token->id ) {
+					$this->execute_sqlite_query( sprintf( 'SAVEPOINT %s', $savepoint_name ) );
+					break;
+				}
+
+				// RELEASE SAVEPOINT.
+				if ( WP_MySQL_Lexer::RELEASE_SYMBOL === $token->id ) {
+					$this->execute_sqlite_query( sprintf( 'RELEASE SAVEPOINT %s', $savepoint_name ) );
 					break;
 				}