import mariadb

db = mariadb.connect(host='10.4.0.8', user='Administrador', password='XXXXX', database='tmp')

qr = db.cursor(buffered=True)

qr.execute('drop table if exists aaa')

qr.execute("""

CREATE TABLE `aaa` (

  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,

  `some_field` varchar(10) DEFAULT '',

  PRIMARY KEY (`id`)

) ENGINE=InnoDB

""")

to_be_inserted = [(None, f'aaa_{i}') for i in range(10)]

qr.executemany('insert into aaa values (?, ?) returning id', to_be_inserted)

inserted = qr.fetchall()

print(f'Should be', len(to_be_inserted), 'got', len(inserted), '. What whas inserted:', inserted)

# ----------------------

qr.execute('drop table if exists aaa_spy')

qr.execute("""

CREATE TABLE `aaa_spy` (

  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,

  `aaa_id` int(10) unsigned NOT NULL,

  `aaa_some_field` varchar(10) DEFAULT '',

  PRIMARY KEY (`id`)

) ENGINE=MyISAM

""")

qr.execute('drop trigger if exists aaa_after_insert')

qr.execute("""

CREATE TRIGGER aaa_after_insert

AFTER INSERT

ON aaa FOR EACH ROW

   insert into aaa_spy values (null, new.id, new.some_field)

""")

to_be_inserted = [(None, f'aaa_{i}') for i in range(10, 20)]

qr.executemany('insert into aaa values (?, ?) returning id', to_be_inserted)

inserted = qr.fetchall()

print(f'Should be', len(to_be_inserted), 'got', len(inserted), '. What whas inserted:', inserted)  # Wrong!

# What was inserted?

qr.execute('select aaa_id, aaa_some_field from aaa_spy where aaa_id >= 11')

# always the same data...

for _id, f in qr:

    print(_id, f)

Should be 10 got 10 . What whas inserted: [(1,), (2,), (3,), (4,), (5,), (6,), (7,), (8,), (9,), (10,)]

Should be 10 got 1 . What whas inserted: [(16,)]

16 aaa_10

16 aaa_10

16 aaa_10

16 aaa_10

16 aaa_10

16 aaa_10

16 aaa_10

16 aaa_10

16 aaa_10