CREATE OR REPLACE FUNCTION get_issue_status_user_role() RETURNS TRIGGER AS
$issue_user_role$
DECLARE missue_id integer;
mstatus integer;
mcurr_user integer;
mrole_descrp varchar;
mcan_edit_tkts boolean;
mqueue_id integer;
BEGIN
raise notice 'howdya';
mcan_edit_tkts := False;
-- Check roles for the logged in user 'before update' event
-- get the queue id of the issue being edited. If user present
-- in user_group_id for the queue id in the q_users_roles
-- check the role(s) with status role of the current user
--IF (TG_OP = 'UPDATE') THEN
-- if OLD.description != NEW.description then
missue_id := OLD.id;
mcurr_user := NEW.updated_by;
mqueue_id := NEW.queue_id;
mstatus := OLD.status;
mrole_descrp := (
SELECT roles.description AS mrole_desc FROM rt_issues
LEFT OUTER JOIN queues ON rt_issues.queue_id = queues.id
LEFT OUTER JOIN rt_status ON rt_issues.status = rt_status.id
LEFT OUTER JOIN q_users_roles ON queues.id = q_users_roles.queue_id
LEFT OUTER JOIN roles ON q_users_roles.role_id = roles.id
LEFT OUTER JOIN users_groups ON q_users_roles.user_group_id = users_groups.id
LEFT OUTER JOIN users ON users_groups."user" = users.id
WHERE rt_issues.id = missue_id AND
rt_issues.status = mstatus AND
users_groups."user" = mcurr_user);
--end if;
if mrole_descrp != 'can_change_status' then
mcan_edit_tkts := False;
else
mcan_edit_tkts := True;
end if;
--END IF;
if mcan_edit_tkts then
raise notice 'Edit permitted';
RETURN NEW;
else
raise notice 'No permission to edit this ticket';
RETURN Null; -- result is ignored since this is an AFTER trigger
end if;
END;
$issue_user_role$ LANGUAGE plpgsql;
drop trigger if exists issue_user_role on rt_issues;
CREATE TRIGGER issue_user_role BEFORE UPDATE OR INSERT ON rt_issues FOR EACH ROW EXECUTE PROCEDURE get_issue_status_user_role();
select语句从角色主服务器返回一个匹配的角色描述，用于与属于users_groups的q_users_roles表中与当前用户的角色相关联的，正在更新的队列的发布状态。在python api调用中使用sqlalchemy-core执行时，sql给出正确的输出（角色描述）。这是我的第一个触发条件。语法错误在哪里
db1=# select id, first_name from users;
id | first_name
----+------------
1 | ytxz
2 | abcd
(2 rows)
db1=# select * from users_groups;
id | user | group |
----+------+-------+
2 | 2 | 1 |
1 | 1 | 2 |
(2 rows)
db1=# select id, cc_user_ids, status, queue_id, updated_by from rt_issues where id=10;
id | cc_user_ids | status | queue_id | updated_by
----+-------------+--------------+--------+----------+---
10 | not@quack.om | 2 | 1 | 2
(1 row)
db1=# select * from rt_status;
id | description | role_id | queue_id |
----+---------------------+---------+----------+
2 | Initial check | 1 | 1 |
3 | Awaiting assignment | 1 | 1 |
1 | New Issue | 1 | 1 |
(3 rows)
db1=# select * from q_users_roles;
id | queue_id | user_group_id | role_id |
----+----------+---------------+---------+
9 | 16 | 1 | 2 |
25 | 21 | 1 | 2 |
26 | 24 | 1 | 2 |
16 | 1 | 1 | 1 |
(4 rows)
db1=# select * from roles;
id | description | xdata
----+----------------------+-------
1 | can_change_status |
2 | can_create_tkts |
(2 rows)
db1=# SELECT roles.description AS mrole_desc FROM rt_issues LEFT OUTER JOIN queues ON rt_issues.queue_id = queues.id LEFT OUTER JOIN rt_status ON rt_issues.status = rt_status.id LEFT OUTER JOIN q_users_roles ON queues.id = q_users_roles.queue_id LEFT OUTER JOIN roles ON q_users_roles.role_id = roles.id LEFT OUTER JOIN users_groups ON q_users_roles.user_group_id = users_groups.id LEFT OUTER JOIN users ON users_groups."user" = users.id WHERE rt_issues.id = 10 AND rt_issues.status = 2 AND users_groups."user" = 1;
mrole_desc
-------------------
can_change_status
(1 row)
db1=# SELECT roles.description AS mrole_desc FROM rt_issues LEFT OUTER JOIN queues ON rt_issues.queue_id = queues.id LEFT OUTER JOIN rt_status ON rt_issues.status = rt_status.id LEFT OUTER JOIN q_users_roles ON queues.id = q_users_roles.queue_id LEFT OUTER JOIN roles ON q_users_roles.role_id = roles.id LEFT OUTER JOIN users_groups ON q_users_roles.user_group_id = users_groups.id LEFT OUTER JOIN users ON users_groups."user" = users.id WHERE rt_issues.id = 10 AND rt_issues.status = 2 AND users_groups."user" = 2;
mrole_desc
------------
(0 rows)
答案 0 :(得分：1)
您如何立即创建触发器，这是关键问题之一
drop trigger if exists issue_user_role on rt_issues;
因此，此后将不会执行触发器。
另一个问题是，鉴于您要强制执行的约束，您可能还希望触发器在插入上触发。
我很难弄清楚您的代码打算做什么。因此，这里不是直接回答您的问题，而是提供了一个基本架构的示例触发器以及其触发方式和触发时间的示例。有一个表值test_table，其中存储一个操作数（value），一元运算（op_code）和result。触发器试图确保存储的result对于给定的value和op_code总是正确的。
DROP TABLE IF EXISTS test_table;
DROP TABLE IF EXISTS test_operations;
CREATE TABLE test_operations (
op_code TEXT PRIMARY KEY
);
INSERT INTO test_operations (op_code) VALUES
('double'),
('triple'),
('negative')
;
CREATE TABLE test_table (
id bigserial PRIMARY KEY,
op_code TEXT REFERENCES test_operations(op_code),
value INTEGER NOT NULL,
result INTEGER NOT NULL
)
;
CREATE OR REPLACE FUNCTION test_table_update_trigger()
RETURNS TRIGGER AS $$
DECLARE
expected_result INTEGER;
BEGIN
expected_result := (
SELECT CASE NEW.op_code
WHEN 'double' THEN NEW.value * 2
WHEN 'triple' THEN NEW.value * 3
WHEN 'negative' THEN -NEW.value
END
);
IF NEW.result != expected_result
THEN
IF NEW.value BETWEEN -10 AND 10
THEN
-- silently ignore the update or insert
RETURN NULL;
ELSIF NEW.value >= 100
THEN
-- modify the update
NEW.result = expected_result;
ELSE
-- abort the transaction
RAISE EXCEPTION
'bad result (%) -- expected % for % %',
NEW.result, expected_result, NEW.op_code, NEW.value;
END IF;
END IF;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
-- remove old trigger if it exists
DROP TRIGGER IF EXISTS my_trigger ON test_table;
-- best practice to create triggers after the function they use
CREATE TRIGGER my_trigger
BEFORE UPDATE OR INSERT
ON test_table
FOR EACH ROW
EXECUTE PROCEDURE test_table_update_trigger();
INSERT INTO test_table (op_code, value, result) VALUES
('double', 2, 4),
('double', 3, 6),
('double', 14, 28),
('triple', 2, 2), -- this insert is ignored
-- ('triple', 14, 14), -- this would be an error
('triple', 120, 0), -- this insert is corrected to have result of 360
('negative', 8, -8)
;
-- this updates targets the first two 'double' rows, but only one row
-- is updated as the trigger returns NULL in one instance
UPDATE test_table
SET
op_code = 'triple',
result = 6
WHERE
op_code = 'double'
AND value < 10 -- remove this clause to see an exception
;
如果您需要更多信息，PostgreSQL docs通常会非常详细。