fix(core): Handle empty executions table in pruning in migrations (#8121

)

In case someone manually prunes their executions table before upgrading
to 1.x, `MigrateIntegerKeysToString` should gracefully handle that,
instead of crashing the application.

## Review / Merge checklist
- [x] PR title and summary are descriptive

packages/cli/src/databases/migrations/sqlite/1690000000002-MigrateIntegerKeysToString.ts

@@ -208,20 +208,24 @@ const pruneExecutionsData = async ({ queryRunner, tablePrefix, logger }: Migrati
 		}
 
 		console.time('pruningData');
-		const counting = (await queryRunner.query(
-			`select count(id) as rows from "${tablePrefix}execution_entity";`,
-		)) as Array<{ rows: number }>;
-
-		const averageExecutionSize = dbFileSize / counting[0].rows;
-		const numberOfExecutionsToKeep = Math.floor(DESIRED_DATABASE_FILE_SIZE / averageExecutionSize);
-
-		const query = `SELECT id FROM "${tablePrefix}execution_entity" ORDER BY id DESC limit ${numberOfExecutionsToKeep}, 1`;
-		const idToKeep = await queryRunner
-			.query(query)
-			.then((rows: Array<{ id: number }>) => rows[0].id);
-
-		const removalQuery = `DELETE FROM "${tablePrefix}execution_entity" WHERE id < ${idToKeep} and status IN ('success')`;
-		await queryRunner.query(removalQuery);
+		const [{ rowCount }] = (await queryRunner.query(
+			`select count(id) as rowCount from "${tablePrefix}execution_entity";`,
+		)) as Array<{ rowCount: number }>;
+
+		if (rowCount > 0) {
+			const averageExecutionSize = dbFileSize / rowCount;
+			const numberOfExecutionsToKeep = Math.floor(
+				DESIRED_DATABASE_FILE_SIZE / averageExecutionSize,
+			);
+
+			const query = `SELECT id FROM "${tablePrefix}execution_entity" ORDER BY id DESC limit ${numberOfExecutionsToKeep}, 1`;
+			const idToKeep = await queryRunner
+				.query(query)
+				.then((rows: Array<{ id: number }>) => rows[0].id);
+
+			const removalQuery = `DELETE FROM "${tablePrefix}execution_entity" WHERE id < ${idToKeep} and status IN ('success')`;
+			await queryRunner.query(removalQuery);
+		}
 		console.timeEnd('pruningData');
 	} else {
 		logger.debug('Pruning was requested, but was not enabled');