All the operations performed after the BEGIN command will be committed to the postgreSQL database only you execute the commit command. Use rollback command to undo all the transactions before it is committed. #
The point of this example is to demonstrate the need for StartTransactionCommand and CommitTransactionCommand to be state smart – they should call CommandCounterIncrement between the calls to BeginTransactionBlock and EndTransactionBlock and outside these calls they need to do normal start, commit o...
declare begin OLD.id := OLD.id+1; raise notice '%, id:%', TG_NAME, OLD.id; return OLD; end; language plpgsql; CREATE FUNCTION postgres=# create trigger tg3 before DELETE ON t_ret for each row execute procedure tg_t_ret(); CREATE TRIGGER postgres=# delete from t_ret where id=1...
cp-r/usr/local/pgsql/data/media/ 但需要注意的是,此种方式由于比较直接,不管是否数据库有无IO情况,因此,备份的时候需要先停止数据库,恢复的时候要删除原数据库文件,重新覆盖回去后,才可以在启动数据库,如果在数据库启动的时候备份,那么,可能会造成数据备份不全,也可以理解为冷备方式。 物理备份的恢复 代码语言...
Here is an example of a function using RETURN NEXT: CREATETABLEfoo (fooidINT, foosubidINT, fooname TEXT);INSERTINTOfooVALUES(1,2,'three');INSERTINTOfooVALUES(4,5,'six');CREATEORREPLACEFUNCTIONget_all_foo()RETURNSSETOF fooAS$BODY$DECLAREr foo%rowtype;BEGINFORrINSELECT*FROMfooWHEREfooid>...
-- an example function which updates a hypothetical -- event_responses table which itself is distributed by event_id CREATE OR REPLACE FUNCTION register_for_event(p_event_id int, p_user_id int) RETURNS void LANGUAGE plpgsql AS $fn$ BEGIN INSERT INTO event_responses VALUES ($1, $2, 'yes...
END IF; Example #1: How to Use IF-THEN-ELSIF Statement in Postgres? Let’s create two variables and assign them some random values: DO $$ DECLARE first_val INT := 72; second_val INT := 50; BEGIN IF first_val < second_val THEN ...
LOOP -- some computations IF count > 0 THEN EXIT; -- exit loop END IF; END LOOP; LOOP -- some computations EXIT WHEN count > 0; -- same result as previous example END LOOP; <> BEGIN -- some computations IF stocks > 100000 THEN EXIT ablock; -- causes exit from the BEGIN block...
通过本文,你将会了解交互式问答系统的原理,学习 PostgreSQL 的向量化存储和检索技术,以及大语言模型交互技术等。 本文就如何利用火山引擎云数据库 PostgreSQL 版和大语言模型技术(Large Language Model,简称 LLM),实现企业级智能交互式问答系统进行介绍。 背景
vitest.sql## Test data example#'Q'"SELECT * FROM aaa"'Y''P'"S1""BEGIN"0'B'"""S1"000'E'""0'C''S'"S1"'P'"foo""SELECT 1"0'B'"myportal""foo"000'E'"myportal"0'P'"S2""COMMIT"0'B'"""S2"000'E'""0'C''S'"S2"'S''Y''X' ...