Just like in most databases, in PostgreSQL a trigger is a way to automatically respond to events. Maybe you want to run a function if data is inserted into a table. Maybe you want to audit the deletion of data,
CREATEORREPLACEFUNCTIONinsert_into_t2()RETURNStriggerAS$$BEGININSERTINTOt2VALUES(NEW.a,NEW.b);RETURNNEW;END;$$languageplpgsql; Event Trigger 创建Event Trigger的语法如下,相比 Trigger 的语法要简单很多 CREATEEVENTTRIGGERnameONevent[WHENfilter_variableIN(filter_value[,...])[AND...]]EXECUTE{FUNCTION|...
ON table_name[--Triggerlogic goes here...]; 3. CREATE[OR REPLACE]FUNCTION function_name(arguments)RETURNS return_datatype AS $variable_name$ DECLARE declaration;[...]BEGIN<function_body>[...]RETURN{variable_name|value}END;LANGUAGE plpgsql;...
In the above syntax, the language used to create the trigger function is PL/pgSQL but we can create it using any of the languages supported by PostgreSQL. The trigger function gets the information about its calling event through TriggerData, which contains some set of local variables. For exa...
I will describe what the return value of the trigger function means and suggest a useful code simplification. Triggers in PostgreSQL A trigger in PostgreSQL consists of two parts: a trigger function the actual trigger, which invokes the trigger function This architecture has the advantage that ...
PostgreSQL-function、trigger 增加一个自动记录更新时间的触发器, 第一步,先写一个函数,返回触发器类型的 1 2 3 4 5 6 7 8 9 create function spam_keyword_update_trigger() returns trigger as $$ begin NEW.tm_update := current_timestamp(0);...
PostgreSQLtrigger（function）examples postgres=# \c warehouse_db You are now connected to database "warehouse_db" as user "postgres".warehouse_db=# set search_path ='record';SET warehouse_db=# show search_path ;search_path --- record (1 row)warehouse_db=# create table warehouse_tb1(wareh...
REFERENCINGis a new option since PostgreSQL 10. You can use it withAFTERtrigger to interact with the overall view of theOLDor theNEW TABLEchanged rows. Examples Create a trigger function that stores the run logic (this is the same as a SQL Server DML trigger). ...
postgresql--Aggregate, Function, Trigger 知乎用户QtzTpp 2 人赞同了该文章 由于知乎精英共和国的文章政治敏感问题,作者带着文章到简书政治避难了,此ID仅作为文章传送/论坛吹牛使用。 特此通知。 three in one. User-defined Aggregateswww.jianshu.com/p/8091e25dd065 Functions, John Shepherd 第一讲...
Event connectors can be combined for where you may invoke a function through Kafka for live notifications, but also invoke it via cron on a periodic basis to pick up any additional work that needs to be processed. The new Postgresql connector ...