PostgreSQL根据条件触发添加/删除数据

我在看似简单的部分寻求帮助，例如根据某些条件将数据插入到另一个表中。所以问题是：有两个表：人：PostgreSQL根据条件触发添加/删除数据

CREATE TABLE "public"."persons" ( 
    "id" Integer DEFAULT nextval('person_id_seq'::regclass) NOT NULL, 
    "surname" Character Varying(100) NOT NULL, 
    "name" Character Varying(100) NOT NULL, 
    "patronymic" Character Varying(100), 
    "date_birth" Date NOT NULL, 
    "place_birth" Character Varying(1000) NOT NULL, 
    "parent_id" Integer, 
    "surnamepat" Character Varying, 
    "surnamepat_short" Character Varying, 
    PRIMARY KEY ("id"));

法定代表人的历史：

CREATE TABLE "public"."history_legal_representatives" ( 
    "id" Integer DEFAULT nextval('history_legal_representative_id_seq'::regclass) NOT NULL, 
    "person_id" Integer NOT NULL, 
    "person_parent_id" Integer NOT NULL, 
    "modified" Date DEFAULT ('now'::text)::date, 
    PRIMARY KEY ("id"));

在哪里：

"person_id" - persons (at table Persons is ID) 
"person_parent_id" - legal representative (at table Persons is parent_id)

什么我想做：

当将添加到表的人的记录中，未指定parent_id时，只需添加此条目，如果指定了parent_id，则添加history_legal_representatives记录： - person_id：= persons.id和person_parent_id：= persons.parent_id。

当在表人员编辑记录，如果PARENT_ID的值变为NULL，从history_legal_representatives删除这样的一对。（如果这样的逻辑不正确，请说明原因\作为更正确的）

代码：

添加

CREATE TRIGGER addrep BEFORE INSERT ON "public"."persons" FOR EACH ROW EXECUTE PROCEDURE addrepresentative()[/SRC] 

CREATE OR REPLACE FUNCTION public.addrepresentative() 
RETURNS trigger 
LANGUAGE plpgsql 
AS $function$ 
BEGIN 
    if NEW.parent_id != NULL then 
    insert into history_legal_representatives (person_id, person_parent_id) 
    values (NEW.id, NEW.parent_id); 
    end if; 
    RETURN NEW; 
END; 
$function$

删除

CREATE TRIGGER delrep BEFORE UPDATE ON "public"."persons" FOR EACH ROW EXECUTE PROCEDURE delrepresentative() 

CREATE OR REPLACE FUNCTION public.delrepresentative() 
RETURNS trigger 
LANGUAGE plpgsql 
AS $function$ 
BEGIN 
    if NEW.parend_id = null then 
    delete from history_legal_representatives where id = NEW.id; 
    end if; 
    RETURN NEW; 
END; 
$function$

来源

2017-07-31 Maxim Stogniy

需要什么要与代码做任何错误？ –

不工作因为SQL中的NULL比较具有不同的语法（+ delporepresentative中的拼写错误）和删除fu nction要通过person_id

固定码删除：

CREATE OR REPLACE FUNCTION public.addrepresentative() 
    RETURNS trigger 
LANGUAGE plpgsql 
AS $function$ 
BEGIN 
    if NEW.parent_id IS NOT NULL then 
    insert into history_legal_representatives (person_id, person_parent_id) 
    values (NEW.id, NEW.parent_id); 
    end if; 
    RETURN NEW; 
END; 
$function$ 

CREATE OR REPLACE FUNCTION public.delrepresentative() 
    RETURNS trigger 
LANGUAGE plpgsql 
AS $function$ 
BEGIN 
    if NEW.parent_id IS null then 
    delete from history_legal_representatives where person_id = NEW.id; 
    end if; 
    RETURN NEW; 
END; 
$function$

检查文档https://www.postgresql.org/docs/9.6/static/sql-createtrigger.html，我认为你需要AFTER触发在这种情况下

来源

2017-07-31 05:51:38 cske

是的......它是一个失败，IS NOT NULL或IS NULL是正确的，而AFTER也是。 –

所有是正确的.. –

PostgreSQL根据条件触发添加/删除数据

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