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CREATE TABLE test1 (a int, b text);
CREATE PROCEDURE transaction_test1()
LANGUAGE plpythonu
AS $$
for i in range(0, 10):
plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
if i % 2 == 0:
plpy.commit()
else:
plpy.rollback()
$$;
CALL transaction_test1();
SELECT * FROM test1;
a | b
---+---
0 |
2 |
4 |
6 |
8 |
(5 rows)
TRUNCATE test1;
DO
LANGUAGE plpythonu
$$
for i in range(0, 10):
plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
if i % 2 == 0:
plpy.commit()
else:
plpy.rollback()
$$;
SELECT * FROM test1;
a | b
---+---
0 |
2 |
4 |
6 |
8 |
(5 rows)
TRUNCATE test1;
-- not allowed in a function
CREATE FUNCTION transaction_test2() RETURNS int
LANGUAGE plpythonu
AS $$
for i in range(0, 10):
plpy.execute("INSERT INTO test1 (a) VALUES (%d)" % i)
if i % 2 == 0:
plpy.commit()
else:
plpy.rollback()
return 1
$$;
SELECT transaction_test2();
ERROR: invalid transaction termination
CONTEXT: PL/Python function "transaction_test2"
SELECT * FROM test1;
a | b
---+---
(0 rows)
-- also not allowed if procedure is called from a function
CREATE FUNCTION transaction_test3() RETURNS int
LANGUAGE plpythonu
AS $$
plpy.execute("CALL transaction_test1()")
return 1
$$;
SELECT transaction_test3();
ERROR: spiexceptions.InvalidTransactionTermination: invalid transaction termination
CONTEXT: Traceback (most recent call last):
PL/Python function "transaction_test3", line 2, in <module>
plpy.execute("CALL transaction_test1()")
PL/Python function "transaction_test3"
SELECT * FROM test1;
a | b
---+---
(0 rows)
-- DO block inside function
CREATE FUNCTION transaction_test4() RETURNS int
LANGUAGE plpythonu
AS $$
plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
return 1
$$;
SELECT transaction_test4();
ERROR: spiexceptions.InvalidTransactionTermination: invalid transaction termination
CONTEXT: Traceback (most recent call last):
PL/Python function "transaction_test4", line 2, in <module>
plpy.execute("DO LANGUAGE plpythonu $x$ plpy.commit() $x$")
PL/Python function "transaction_test4"
-- commit inside subtransaction (prohibited)
DO LANGUAGE plpythonu $$
with plpy.subtransaction():
plpy.commit()
$$;
WARNING: forcibly aborting a subtransaction that has not been exited
ERROR: cannot commit while a subtransaction is active
CONTEXT: PL/Python anonymous code block
-- commit inside cursor loop
CREATE TABLE test2 (x int);
INSERT INTO test2 VALUES (0), (1), (2), (3), (4);
TRUNCATE test1;
DO LANGUAGE plpythonu $$
for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
plpy.commit()
$$;
ERROR: cannot commit transaction while a cursor is open
CONTEXT: PL/Python anonymous code block
SELECT * FROM test1;
a | b
---+---
(0 rows)
-- rollback inside cursor loop
TRUNCATE test1;
DO LANGUAGE plpythonu $$
for row in plpy.cursor("SELECT * FROM test2 ORDER BY x"):
plpy.execute("INSERT INTO test1 (a) VALUES (%s)" % row['x'])
plpy.rollback()
$$;
ERROR: cannot abort transaction while a cursor is open
CONTEXT: PL/Python anonymous code block
SELECT * FROM test1;
a | b
---+---
(0 rows)
DROP TABLE test1;
DROP TABLE test2;
|
