BEGIN;
BEGIN
SELECT * FROM non_existing_table;
ERROR:  relation "non_existing_table" does not exist
LINE 1: SELECT * FROM non_existing_table;
                      ^
SELECT 1;
ERROR:  current transaction is aborted, commands ignored until end of transaction block
DETAIL:  statement: SELECT 1;
END;
ROLLBACK
BEGIN;
BEGIN
aaa;
ERROR:  syntax error at or near "aaa"
LINE 1: aaa;
        ^
SELECT 1;
ERROR:  current transaction is aborted, commands ignored until end of transaction block
DETAIL:  statement: SELECT 1;
END;
ROLLBACK
SELECT 1;
 ?column? 
----------
        1
(1 row)

