插入后如何在 Firebird 触发器中 select 列名

Question

我正在使用 Firebird 触发器。我想在插入触发器后在 party_id 的基础上获取 party_name。并将 party_name 插入日志 table。这是我的代码。

SET TERM ^ ;
CREATE TRIGGER cash_after_insert CASH_FLOW 
AFTER INSERT 
POSITION 0 
AS
DECLARE getPartyName for
(select party_name from party where party_id=NEW.party_id);
BEGIN
insert into logs(date,username,logs)values('now',getPartyName,'added data');
END^
SET TERM ; ^

Answer 1

您正在声明 a cursor, which requires additional statements (OPEN, FETCH, and CLOSE) 以实际检索值。相反，您可以使用 select 表达式，这比使用显式游标要简单得多：

insert into logs(date,username,logs) values (
  'now', 
  (select party_name from party where party_id = NEW.party_id), 
  'added data');

顺便说一句，您在问题中使用的语法不正确（或至少不完整）。例如create trigger语句应该是CREATE TRIGGER cash_after_insert for CASH_FLOW，游标声明漏了CURSOR关键字（DECLARE getPartyName cursor for ...），而date是保留字，所以需要加引号("DATE").

换句话说，使用：

SET TERM ^ ;
CREATE TRIGGER cash_after_insert for CASH_FLOW 
AFTER INSERT 
POSITION 0 
AS
BEGIN
insert into logs ("DATE", username, logs) values (
  'now', 
  (select party_name from party where party_id = NEW.party_id),
  'added data');
END^
SET TERM ; ^

插入后如何在 Firebird 触发器中 select 列名

How to select column name in Firebird trigger after insert

sql

triggers

firebird