triggers

问题 I am trying to create a trigger which will update the grades of all the friends of a student whose grade is updated. create trigger upgrade after update on Highschooler when new.grade=old.grade+1 and trigger_nestlevel() < 2 begin update Highschooler set grade=new.grade where ID in ( select ID2 from Friend where ID1=old.ID ) ; end friends of friends (of friends...) of the person whose grade is increased are also being 'upgraded' how can i stop this? 回答1: As you can read in Limits In SQLite you

问题 I am trying to find an example of how to update a view on multiple tables using an instead of trigger. That is I want update more than one table that this view selects from. I cant find any examples. If someone can show me how to this that would be great. 回答1: Assuming that you're using SQLServer here is one oversimplified example CREATE TABLE persons (personid int, firstname varchar(32), lastname varchar(32)); CREATE TABLE employees (employeeid int, personid int, title varchar(32)); CREATE

问题 I am trying to find an example of how to update a view on multiple tables using an instead of trigger. That is I want update more than one table that this view selects from. I cant find any examples. If someone can show me how to this that would be great. 回答1: Assuming that you're using SQLServer here is one oversimplified example CREATE TABLE persons (personid int, firstname varchar(32), lastname varchar(32)); CREATE TABLE employees (employeeid int, personid int, title varchar(32)); CREATE

问题 I have a table which contains a tree like structure It takes the form of: -nodeID,fkID,parentNode (parentNode is NULL if it is the root and the nodeID of its parent if it is a child) (fkID is NULL if it is not the root) the fkID is a FK which when deleted in another table cascades its delete to this table. This cascading delete only however references the root node. There is another constraint put on the database in which a root node cannot be deleted unless its children are deleted first.

问题 I want to know if we can create a trigger in MS SQL server which triggers a php script on each insertion of record 回答1: Not sure why you want it, but try something in the line of: DELIMITER @@ CREATE TRIGGER SomeTrigger AFTER INSERT ON SomeTable FOR EACH ROW BEGIN DECLARE cmd CHAR(255); DECLARE result int(10); SET cmd=CONCAT('sudo /path/to/php -f file.php'); SET result = sys_exec(cmd); END; @@ DELIMITER ; 回答2: I feel it break multilevel architecture and bad idea If it local php script, must

问题 In answering Will I miss any changes if I replace an oracle trigger while my application is running?, I went looking to see if the trigger was locked by an INSERT statement. It wasn't and I can't find anything on the internet to suggest that a trigger can be locked. If I run the following in one session: create table test_trigger (id number); create table test_trigger_h (id number); create or replace trigger test_trigger_t after insert on test_trigger for each row begin insert into test

问题 In answering Will I miss any changes if I replace an oracle trigger while my application is running?, I went looking to see if the trigger was locked by an INSERT statement. It wasn't and I can't find anything on the internet to suggest that a trigger can be locked. If I run the following in one session: create table test_trigger (id number); create table test_trigger_h (id number); create or replace trigger test_trigger_t after insert on test_trigger for each row begin insert into test

问题 As it seems like I have found a bug in jquery: jquery draggable throws error when 'mouseup' is triggered Can I get some advice on how to implement the following functionality without using the trigger? I want to be able to stop an element to be dragged when a condition has been reached, I have been trying lot's of possibilities but none works automatically, even though the event is fired when condition is true it only takes effect when you "mouseup" the dragger. I'm really trapped on this,

问题 I recently started working with AWS. I have integrated AWS Amplify using cognito user pools for my user management(login&signup) and it went perfect(User pool gets updated whenever a new user registers). Now i have added an Cognito Post confirmation trigger to save the registered email into database and here is my trigger codevar mysql = require('mysql'); var config = require('./config.json'); var pool = mysql.createPool({ host : config.dbhost, user : config.dbuser, password : config

问题 I have an application which connects to SQL Server 2000 (using a generic SQL Login and SQL Authentication). I would like to implement some logging via triggers to track data changes. I can't use USER_NAME() because that returns the generic account. I've poked through master..sysprocesses and it doesn't seem to record the username (although it does record the machine name). Any ideas how, within SQL, to gain access to the username? (Note: yes, I could pass it in as a variable via the