各位用户为了找寻关于在postgresql中结束掉正在执行的SQL语句操作的资料费劲了很多周折。这里教程网为您整理了关于在postgresql中结束掉正在执行的SQL语句操作的相关资料,仅供查阅,以下为您介绍关于在postgresql中结束掉正在执行的SQL语句操作的详细内容
结束进程两种方式:
? 1SELECT
pg_cancel_backend(PID)
取消后台操作,回滚未提交事物 (select);
? 1SELECT
pg_terminate_backend(PID)
中断session,回滚未提交事物(select、update、delete、drop);
? 1SELECT
*
FROM
pg_stat_activity;
根据datid=10841
? 1SELECT
pg_terminate_backend (10841);
补充:PostgreSQL无法在PL / pgSQL中开始/结束事务
我正在寻求澄清如何确保plpgsql函数中的原子事务,以及为数据库进行此特定更改设置了隔离级别.
在下面显示的plpgsql函数中,我想确保BOTH的删除和插入成功.当我尝试将它们包装在一个事务中时,我收到一个错误:
错误:无法在PL / pgSQL中开始/结束事务.
如果另一个用户在此功能已删除自定义记录之后,但在此函数有机会插入自定义记录之前,为情况(RAIN,NIGHT,45MPH)添加了默认行为,下面的函数执行过程中会发生什么?是否有一个隐式事务包装插入和删除,以便如果另一个用户已经更改了此函数引用的任何一个行,两者都将回滚?我可以设置此功能的隔离级别吗?
? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24create
function
foo(v_weather
varchar
(10), v_timeofday
varchar
(10), v_speed
varchar
(10),
v_behavior
varchar
(10))
returns
setof CUSTOMBEHAVIOR
as
$body$
begin
-- run-time error if either of these lines is un-commented
-- start transaction ISOLATION LEVEL READ COMMITTED;
-- or, alternatively, set transaction ISOLATION LEVEL READ COMMITTED;
delete
from
CUSTOMBEHAVIOR
where
weather =
'RAIN'
and
timeofday =
'NIGHT'
and
speed=
'45MPH'
;
-- if there is no default behavior insert a custom behavior
if
not
exists
(
select
id
from
DEFAULTBEHAVIOR
where
a =
'RAIN'
and
b =
'NIGHT'
and
c=
'45MPH'
)
then
insert
into
CUSTOMBEHAVIOR
(weather, timeofday, speed, behavior)
values
(v_weather, v_timeofday, v_speed, v_behavior);
end
if;
return
QUERY
select
*
from
CUSTOMBEHAVIOR
where
... ;
-- commit;
end
$body$
LANGUAGE plpgsql
一个plpgsql函数在事务中自动运行.这一切都成功了,一切都失败了.
我引用the manual on plpgsql functions:
Functions and trigger procedures are always executed within a transaction established by an outer query — they cannot start or commit that transaction, since there would be no context for them to execute in. However, a block containing an EXCEPTION clause effectively forms a subtransaction that can be rolled back without affecting the outer transaction.
所以,如果你需要,你可以捕获理论上可能发生的异常(但是不大可能).
Details on trapping errors in the manual.
您的功能审查和简化:
? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23CREATE
FUNCTION
foo(v_weather text
, v_timeofday text
, v_speed text
, v_behavior text)
RETURNS
SETOF custombehavior
AS
$body$
BEGIN
DELETE
FROM
custombehavior
WHERE
weather =
'RAIN'
AND
timeofday =
'NIGHT'
AND
speed =
'45MPH'
;
INSERT
INTO
custombehavior (weather, timeofday, speed, behavior)
SELECT
v_weather, v_timeofday, v_speed, v_behavior
WHERE
NOT
EXISTS (
SELECT
1
FROM
defaultbehavior
WHERE
a =
'RAIN'
AND
b =
'NIGHT'
AND
c =
'45MPH'
);
RETURN
QUERY
SELECT
*
FROM
custombehavior
WHERE
... ;
END
$body$LANGUAGE plpgsql
以上为个人经验,希望能给大家一个参考,也希望大家多多支持。如有错误或未考虑完全的地方,望不吝赐教。
原文链接:https://blog.csdn.net/weixin_44087826/article/details/85625244