我查看了this类似的问题,但我认为我的问题可能有所不同。如果我正确理解他们的问题,问题是由上游语法错误引起的。
在我的例子中,语法错误非常接近程序的开头,它让我有一个狭窄的窗口可以看到可能出错的地方,但在我看来一切正常。
代码:
DO $$
DECLARE topic_cursor CURSOR FOR SELECT * FROM "socialMediaModel_topic" WHERE "active_search"=True;
BEGIN
OPEN topic_cursor;
FETCH FIRST FROM topic_cursor;
LOOP
SELECT "topic" FROM topic_cursor AS "c_topic";
SELECT "topic_id" FROM topic_cursor AS "c_id";
SELECT "active_search" FROM topic_cursor AS "c_active";
INSERT INTO "socialMediaModel_datacollection" ("name", "active")
VALUES (c_topic, c_active);
INSERT INTO "socialMediaModel_datacollectiontopic" ("data_collection_id_id", "topic_id_id")
VALUES ((SELECT "data_collection_id" FROM "DataCollection" where name=c_topic), c_id);
FETCH NEXT FROM topic_cursor;
END LOOP;
CLOSE topic_cursor;
UPDATE "socialMediaModel_topic" SET "active_search" = False WHERE "active_search"=True;
COMMIT;
END$$;
错误:
ERROR: syntax error at or near ";"
LINE 9: FETCH FIRST FROM topic_cursor;
^
********** Error **********
ERROR: syntax error at or near ";"
SQL state: 42601
Character: 247
我在编写此脚本时几乎完全遵循了这些资源:
数据库:PostgreSQL 9.1
编辑:pgAdmin III 查询工具
如果我遗漏了一些非常明显的东西,我提前道歉。我整天都在盯着这个脚本,所以我的大脑可能有点困惑。
最佳答案
程序解决方案
你的代码中有很多问题。
这应该可以工作,而且速度更快:
DO
$do$
DECLARE
rec record;
BEGIN
FOR rec IN
SELECT s.*, d.data_collection_id
FROM "socialMediaModel_topic" s
LEFT JOIN "DataCollection" d ON d.name = s.topic
WHERE active_search
LOOP
INSERT INTO "socialMediaModel_datacollection" (name, active)
VALUES (rec.topic, rec.active_search);
INSERT INTO "socialMediaModel_datacollectiontopic"
(data_collection_id_id, topic_id_id)
VALUES (rec.data_collection_id, rec.topic_id);
END LOOP;
UPDATE "socialMediaModel_topic"
SET active_search = FALSE
WHERE active_search;
END
$do$;
要点
FETCH
syntax不正确。DO
语句中没有COMMIT
。整个事情在单个事务中自动运行,就像一个函数。您没有条件终止循环。
几乎不需要显式游标。使用
FOR
loop 的更方便(通常更快)的隐式游标.我建议不要在 Postgres 中使用 CaMeL 大小写标识符。仅使用合法的小写标识符。
基于集合的解决方案
整个程序方法不如 data-modifying CTEs 的基于集合的方法:
WITH ins1 AS (
INSERT INTO "socialMediaModel_datacollection" (name, active)
SELECT topic, active_search
FROM "socialMediaModel_topic"
WHERE active_search
)
, ins2 AS (
INSERT INTO "socialMediaModel_datacollectiontopic"
(data_collection_id_id, topic_id_id)
SELECT d.data_collection_id, s.topic_id
FROM "socialMediaModel_topic" s
LEFT JOIN "DataCollection" d ON d.name = s.topic
WHERE s.active_search
)
UPDATE "socialMediaModel_topic"
SET active_search = FALSE
WHERE active_search;
或者,如果您有并发写入负载,请使用FOR UPDATE
来避免竞争条件:
WITH sel AS (
SELECT s.topic_id, s.topic, s.active_search, d.data_collection_id
FROM "socialMediaModel_topic" s
LEFT JOIN "DataCollection" d ON d.name = s.topic
WHERE s.active_search
FOR UPDATE
)
, ins1 AS (
INSERT INTO "socialMediaModel_datacollection" (name, active)
SELECT topic, active_search FROM sel
)
, ins2 AS (
INSERT INTO "socialMediaModel_datacollectiontopic"
(data_collection_id_id, topic_id_id)
SELECT d.data_collection_id, s.topic_id FROM sel
)
UPDATE "socialMediaModel_topic"
SET active_search = FALSE
WHERE active_search;
有关 CTE 中的 SELECT ... FOR UPDATE
的更多信息:
Should I include SELECTs in a transaction?
类似问题/答案:
How to improve performance of a function with cursors in PostgreSQL?
关于sql - ";"处或附近的 plpgsql 语法错误,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24619913/