Questions tagged [trigger]

Procedural code automatically executed in response to a database event.

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7
votes
2answers
5k views

Trigger in MySQL to prevent insertion

I want to create the trigger which prevents insertion in the reservation table of flights (numflights) which does not exist. Tables ---------------------------------------------- flights(numflight, ...
16
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4answers
84k views

Call a stored procedure from a trigger

I have created a stored procedure in mysql using the following syntax. DROP PROCEDURE IF EXISTS `sp-set_comment_count`; DELIMITER $$ CREATE PROCEDURE `sp_set-comment_count` (IN _id INT) BEGIN -- ...
12
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3answers
6k views

Dynamic SQL in MySQL stored routines

According to the restrictions on stored routines and triggers, dynamic sql cannot be used (restriction lifted for stored procedures in version 5.0.13 and later). Why is this limitation in place? And ...
10
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2answers
11k views

Performance of a Trigger vs Stored Procedure in MySQL

A post here on DBA.StackExchange (What are the best practices for triggers to maintain a revision number on records?) has spawned an interesting question (at least, interesting to me) regarding ...
10
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1answer
1k views

Permissions in triggers when using cross database certificates

I use cross database certificates (as explained by Erland Sommarskog) to control access to a certain database in my environment ( SQL Server 2008 R2 ). I have stored procedures in database A that ...
5
votes
3answers
17k views

Disable trigger for just one table

Is it possible to disable a trigger momentarily but for just one table. For example I have table, TableA with an on insert, update and delete trigger. I also have a table B with the same triggers but ...
9
votes
1answer
24k views

Can mysqldump dump triggers and procedures?

Is there any way of making a mysqldump which will save all the triggers and procedures from a specified db? Some time ago I read that mysqldump will also save my triggers, but it doesn't look like it....
4
votes
2answers
2k views

Create a trigger on all the last_modified columns in PostgreSQL

In PostgreSQL 9.5, I have tables with columns in the form prefix_last_modified timestamp without time zone NOT NULL DEFAULT (clock_timestamp() AT TIME ZONE 'UTC') I was looking for a way to set ...
3
votes
2answers
4k views

Assign to NEW by key in a Postgres trigger

In the trigger body, how can I assign a value to NEW by it's field name? That's what I want to do: some_key = "some_column"; NEW[some_key] = 5;
6
votes
3answers
4k views

How to prevent a PostgreSQL trigger from being fired by another trigger?

I have 2 triggers on one table; one works for INSERTs : CREATE TRIGGER "get_user_name" AFTER INSERT ON "field_data" FOR EACH ROW EXECUTE PROCEDURE "add_info"(); This updates some values in the table....
9
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4answers
5k views

How can I know which stored procedure or trigger is using a table on SQL Server 2008 R2?

This is the case that in the DB I'm checking, there is an archive table which keeps the user history, and there is a trigger or store procedure that after some time delete rows from this table, in ...
5
votes
1answer
709 views

How to Choose Between VALUES and SELECT for INSERT?

This answer raised the question for me how to choose between VALUES and SELECT in such a function . Using PostgreSQL 9.4.3 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit: ...
4
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1answer
13k views

SELECT in trigger function in two tables

My table and trigger in PostgreSQL 9.4.3 on x86_64-unknown-linux-gnu, compiled by gcc (Debian 4.9.2-10) 4.9.2, 64-bit: CREATE TABLE measurements ( measurement_id SERIAL PRIMARY KEY NOT NULL, ...
2
votes
2answers
600 views

Trigger to get next prefixed ID: Is there a better way?

I have a projects table: +------------+-----+ | PROJECT_ID | ... | +------------+-----+ | LC000001 | | | LC000002 | | | LC000003 | | | LC000004 | | | LC000005 | | +------...
26
votes
1answer
26k views

Trigger in combination with transaction

Suppose we have the following situation: We have a table (let's say Table_A), wich has a trigger on INSERT. The trigger job is to update some rows in table_B based on the inserted values in table_A. ...
7
votes
4answers
64k views

Create a trigger to update table data on another Server's database

I am creating a trigger in MySQL and I need a little help. I have 2 websites, 2 databases (same name) on 2 different web servers, S1 & S2. These databases have the same tables names. I want ...
15
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3answers
10k views

SQL Server : How to disable trigger for an update only for your current session?

I am working on SQL Server 2008 R2. I have a table benefit which has a AFTER INSERT, UPDATE trigger named tiu_benefit. I want to write an UPDATE statement for this table to update 1 row but I dont ...
11
votes
1answer
7k views

What are the privileges required to execute a trigger function in PostgreSQL 8.4?

What are the privileges required to execute a trigger function in PostgreSQL 8.4? It seems that the privileges set to a role does not matter to execute a trigger function. I think I have seen some ...
21
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4answers
19k views

How to limit maximum number of rows in a table to just 1

I have a configuration table in my SQL Server database and this table should only ever have one row. To help future developers understand this I'd like to prevent more than one row of data being added....
8
votes
3answers
10k views

Launching a python script from an insert trigger

We have a nice piece of python that sends some emails and interacts with a cloud system. Works fine. But we have to fire it every few minutes to poll the db. We really need, for business purposes, to ...
5
votes
7answers
591 views

Policies RE database triggers in well-designed applications?

I've heard all kinds of horror stories around gremlins living in database triggers, and--worse--systems being brought down by the addition of a trigger that caused a chain of cascading ones. I'm ...
12
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2answers
2k views

What is a “transition table" in Postgres?

The page describing what's new in Postgres 10 mentions “Transition Tables for Triggers”. Transition Tables for Triggers This feature makes AFTER STATEMENT triggers both useful and performant ...
12
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3answers
3k views

How to change the firing order of Triggers?

Realy I rarely use triggers. So I met a problem at first time. I have a lot of tables with triggers (2 or more for every table). I would like to know and change the order of firing triggers for every ...
7
votes
1answer
5k views

SQL Server 2016: Temporal table performance vs. Triggers and CDC

It seems to be quite difficult to find comparisons between system-versioned temporal tables and the older options, such as DB triggers and CDC. I currently don't have the time to write an extended ...
6
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2answers
6k views

Does a TRIGGER improve the performance?

I understand that TRIGGERs are useful, as they take care of subsequent queries, but do they have an advantage from performance point of view too? Replacing two or three queries as INSERT INTO table1 ...
5
votes
2answers
3k views

Implementing a Circular Buffer (Sliding window) in MySQL

I intend to store some Java objects in a MySQL database, accompanied by a timestamp. These objects should be kept in a Sliding Window fashion (also known as Circular Buffer), meaning that only the ...
4
votes
2answers
20k views

Why TRY CATCH does not suppress exception in trigger

I have a trigger on a table (source) that data should be copied to the other one (target) in other database. I am trying to implement custom synchronization process for data: I want that target ...
4
votes
1answer
17k views

BEFORE INSERT trigger in MySQL

I am new to MySQL and I'm having problems creating a BEFORE INSERT trigger. I get an unexpected END error. I have a table named verlof_aanvragen with a column datum (and 6 more columns). What I ...
2
votes
2answers
2k views

Trigger to create a variable Table to be sent to service broker

I've setup a service broker for the first time and tested it... Looks good. Everytime a DML operation happens on a specific table; Let's say the Price Table, a trigger calls a stored procedure passing ...
8
votes
3answers
5k views

Using MySQL triggers or transactions?

I want to ask your opinion in using MySQL triggers or transactions in a website. Actually I have a history payment table with - UserId | OperationId | Comment | Credits | Sign (debit or credit). So ...
6
votes
5answers
2k views

Making a column immutable in MySQL

I want to make a column in a relation unmodifyable for consistency reasons. The backstory is that I have a n:n relationship where the "connecting" relation has additional values. I don't want that ...
3
votes
3answers
2k views

PostgreSQL trigger function that selects from %current% table

I have multiple tables that have the same column names, they only vary in their column values, like: tbl_log_a tbl_log_b tbl_log_c ... 26 tables from a to z. Each table has a trigger that calls a ...
3
votes
2answers
5k views

Table data transfer using SSIS and triggers on destination table

I'm a novoice in db operations. SQL Server 2008 R2 is the database I'm using. I need to move selected rows from a staging database table to production database table. I'm using SSIS package to do ...
3
votes
2answers
8k views

Comparing dates in a BEFORE INSERT trigger

I need help making a TRIGGER that compares two dates being entered into a table, but I'm not 100% on the syntax I should use. Something like: CREATE TRIGGER chk_dates BEFORE INSERT ON `...
1
vote
2answers
966 views

Tables accessed during last period

I want to check which tables have been updated during a given period, for instance in descending order of access time per table. How can I get that for PostgreSQL?
1
vote
2answers
3k views

Send email when some users connect to SQL Server

I am looking for a way to create a logon trigger in SQL Server. Basically i need to do is when it matches some users or profiles on logon it send an alert e-mail. I have found some things for Oracle ...
1
vote
1answer
3k views

MYSQL Trigger not working

I am trying to create the following trigger: CREATE TRIGGER update_customers AFTER INSERT ON wp_usermeta FOR EACH ROW BEGIN if new.wp_metakey = first_name then insert into ...
1
vote
1answer
4k views

mysql trigger / stored procedure - update another table row by row

I've already, searched and read, many answers about this issue for 3 days, but couldn't get a clear answer on how to do this. this will be a little long, be patient please. First of all, I am trying ...
0
votes
2answers
57 views

Oracle Custom Sequence of a partitioned group (Insert trigger)

Please help, need an insert trigger to insert the group_ID (next sequential number) of a partitioned group. Much like a dense_rank of repeating group of names. When a new record is created, if the ...
0
votes
1answer
1k views

Trigger function using current row and current table name as variables

Like detailed in my first question I have multiple tables with identical layout in a Postgres 9.1 DB. They only vary in their column values: tbl_log_a tbl_log_b tbl_log_c ... 26 tables (from a to z)....
17
votes
1answer
6k views

What is the quickest way to purge data?

Scenario: We have two tables Tbl1 & Tbl2 on the Subscriber Server. The Tbl1 is being replicated from Publisher Server A and it has two triggers - insert and update. The triggers are inserting and ...
13
votes
3answers
10k views

Is it possible to get execution call stack in a trigger?

I have 10 stored procedures and each of them does INSERTs into one tableX. Is it possible in a trigger body of tableX to get what object causes modification of tableX (stored proc1 or sp2 or....) ? ...
8
votes
1answer
7k views

How to access NEW or OLD field given only the field's name?

I'm writing a validation trigger. The trigger must validate that the sum of an array equals another field. Since I have many instances of this validation, I want to write a single procedure and create ...
12
votes
1answer
19k views

How to use COLUMNS_UPDATED to check if any of certain columns are updated?

I have table with 42 columns and a trigger which should do some stuff when 38 of these columns are updated. So, I need to skip the logic if the rest 4 columns are changed. I can use UPDATE() function ...
5
votes
3answers
1k views

Is there a way in SQL Server to make a table only able to insert by trigger?

The title is pretty self explanatory but if your'e curious as to why I want this; I want this because I have an archive/log table that stores past values of an active table and due to this I don't ...
2
votes
3answers
4k views

What are the best practices for triggers to maintain a revision number on records?

I have an audit trail implemented on an application database that captures old value, new value, modification time, and user inserting it into another table. I'm now wanting to add a revision number ...
22
votes
2answers
2k views

Do triggers compile each time?

We are troubleshooting a server that has high CPU utilization. After finding that the queries weren't really causing it, we started looking into compilations. Performance Monitor is showing less than ...
10
votes
1answer
1k views

What is the correct way to ensure unique entries in a temporal database design?

I'm having trouble with the design of a temporal database. I need to know how to make sure I have only one active record for any given timeframe for a store. I have read this answer, but I'm afraid I ...
5
votes
1answer
4k views

Trigger function taking column names as parameters to modify the row

I am trying to write a trigger function in Postgres 9.4. Something like this (not working, yet): CREATE FUNCTION set_point_from_coords(source _regclass, target _regclass) RETURNS trigger AS $...
3
votes
2answers
23k views

How to make a trigger that will compare input with a value of other table?

I had made two tables with the following fields: TABLE 1: "Bookings" FIELD: "fk_flight_number" FIELD: "date_of_reservation" TABLE 2: "Flights" FIELD: "flight_number" FIELD: "...