I used this example and it worked well when all my tables were in public schema.
But trigger hasn't been working since I separated tables into different schemas and applied inheriting.
Here is example of my structure:
CREATE SCHEMA common;
CREATE SCHEMA video;
CREATE TABLE common.file (
file_id SERIAL PRIMARY KEY,
url VARCHAR(255) NOT NULL,
mime_type VARCHAR(31) DEFAULT '' NOT NULL,
size INTEGER NOT NULL,
modified TIMESTAMP DEFAULT CURRENT_TIMESTAMP NOT NULL
);
CREATE TABLE video.file (
width INTEGER NOT NULL,
height INTEGER NOT NULL,
local_path VARCHAR(255) DEFAULT '' NOT NULL
)
INHERITS (common.file);
CREATE FUNCTION common.update_modified()
RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
NEW.modified = now();
RETURN NEW;
END;
CREATE TRIGGER update_modified
BEFORE UPDATE ON common.file
FOR EACH ROW EXECUTE PROCEDURE common.update_modified();
When I do UPDATE common.file ... or UPDATE video.file ... field common.file.modified doesn't change itself. It seems trigger doesn't run, but I don't understand why.
What should I do to repair the behavior?
In described issue trigger is set only on common.file, so UPDATE common.file ... doesn't work if row inserted in video.file
Documentation says: INSERT always inserts into exactly the table specified
So trigger should be applied to both common.file and video.file.
-- Creating schemas and tables the same
-- Let function be in public scheme
CREATE FUNCTION update_modified()
RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
NEW.modified = now();
RETURN NEW;
END;
CREATE TRIGGER update_modified
BEFORE UPDATE ON common.file
FOR EACH ROW EXECUTE PROCEDURE update_modified();
CREATE TRIGGER update_modified
BEFORE UPDATE ON video.file
FOR EACH ROW EXECUTE PROCEDURE update_modified();
In that case when we update rows inserted either in common.file or in video.file corresponding trigger will call.
Related
here is my script:
CREATE SCHEMA IF NOT EXISTS {accountId};
CREATE TABLE IF NOT EXISTS {accountId}.{tableCommandsName}
(
id int GENERATED ALWAYS AS IDENTITY,
ts timestamp WITHOUT TIME ZONE NOT NULL,
command varchar NOT NULL,
ts_executed timestamp WITHOUT TIME ZONE,
output varchar
);
CREATE INDEX IF NOT EXISTS idx_commands ON {accountId}.{tableCommandsName} (ts_executed) WHERE ts_executed IS NULL;
CREATE OR REPLACE VIEW {accountId}.pending_commands AS
SELECT id, ts, command from {accountId}.{tableCommandsName} WHERE ts_executed IS NULL ORDER BY ts ASC;
CREATE OR REPLACE FUNCTION {accountId}.on_commands_change ()
RETURNS trigger
LANGUAGE 'plpgsql'
AS $BODY$
DECLARE
notification JSON;
BEGIN
notification = json_build_object(
'table',TG_TABLE_NAME,
'data', row_to_json(NEW));
PERFORM pg_notify('datachange', notification::TEXT);
RETURN NEW;
END
$BODY$;
CREATE OR REPLACE TRIGGER {triggerName}
AFTER INSERT ON {accountId}.{tableCommandsName}
FOR EACH ROW EXECUTE PROCEDURE {accountId}.on_commands_change();
my focus is the line:
CREATE OR REPLACE TRIGGER {triggerName}
where
CREATE OR REPLACE TRIGGER {accountId}.{triggerName}
will not work, but
CREATE OR REPLACE TRIGGER "{accountId}.{triggerName}"
will work, and I don't understand why.
everything else has the schema name in front, but the trigger doesn't want it.
and if I don't put it, it's still created in the right schema. Is it because it's during the same execution as the create schema instruction?
Quote from the manual
The name cannot be schema-qualified — the trigger inherits the schema of its table
I am having a problem with a trigger. I created a trigger and a function
for when performing an INSERT update a field in the same table.
Is returning:
Error: function "loss_func" in FROM has return type trigger that is
not supported LINE 1: SELECT * FROM table.loss_func ()
Function
CREATE OR REPLACE FUNCTION loss_func()
RETURNS trigger AS $loss_func$
BEGIN
NEW.dt_creation := to_char(now(), 'YYYY-MM-DD');
RETURN NULL;
END;
$loss_func$ LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION loss_func()
OWNER TO postgres;
Trigger
CREATE TRIGGER tgr_loss
AFTER INSERT ON loss
FOR EACH ROW
EXECUTE PROCEDURE loss_func();
What am I doing wrong?
A working version of your code.
- The trigger now fires BEFORE insert and updates the value of dt_creation and returns the NEW version of the record :
drop table loss;
create table loss (
id int ,
dt_created varchar);
CREATE OR REPLACE FUNCTION loss_func()
RETURNS trigger AS $loss_func$
BEGIN
NEW.dt_created := to_char(now(), 'YYYY-MM-DD');
RETURN NEW;
END;
$loss_func$ LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION loss_func()
OWNER TO postgres;
CREATE TRIGGER tgr_loss
BEFORE INSERT ON loss
FOR EACH ROW
EXECUTE PROCEDURE loss_func();
insert into loss(id) values(1);
Another solution that i can propose to avoid the usage of a trigger is to use a default value for dt_creation when you create the table (and use timestamp instead of storing the date as varchar) :
...
dt_creation timestamp default now(),
...
or you can alter your table to set the default value to now() :
alter table loss
alter column dt_creation set default now();
I have this table on PostgreSQL and I'd like to make a trigger that every time I edit one row of the table publications the last_edit_date is updated to now():
CREATE FUNCTION trigger_update_question_timestamp()
RETURNS "trigger" AS $func$
BEGIN
UPDATE publications SET last_edit_date = now() WHERE publicationid = NEW.publicationid;
RETURN NULL;
END;
$func$ LANGUAGE plpgsql;
CREATE TRIGGER answer_update_question_timestamp AFTER INSERT OR UPDATE ON publications
FOR EACH ROW EXECUTE PROCEDURE trigger_update_question_timestamp();
CREATE TABLE publications
(
publicationid SERIAL PRIMARY KEY,
body VARCHAR(1000) NOT NULL ,
creation_date TIMESTAMP DEFAULT now() NOT NULL,
userid INTEGER NOT NULL,
last_edit_date TIMESTAMP,
CONSTRAINT body_length CHECK (CHAR_LENGTH(body) >= 10 AND CHAR_LENGTH(body) <= 1000),
CONSTRAINT "FK_publications_users"
FOREIGN KEY ("userid") REFERENCES users ("userid") ON DELETE SET NULL ON UPDATE CASCADE
);
I'm using PhpStorm and when I manually edit a line I get the following error:
[54001] ERROR: stack depth limit exceeded Hint: Increase the configuration parameter "max_stack_depth" (currently 2048kB), after ensuring the platform's stack depth limit is adequate. Where: SQL statement "SELECT 1 FROM ONLY "public"."users" x WHERE "userid" OPERATOR(pg_catalog.=) $1 FOR KEY SHARE OF x" SQL statement "UPDATE publications SET last_edit_date = now() WHERE publicationid = NEW.publicationid" PL/pgSQL function trigger_update_question_timestamp()
What does this exactly means? Does it have to do with my trigger or any other definition?
Your trigger is recursive, that is, the trigger function executes an UPDATE that calls the trigger function again.
The solution here is to use a BEFORE INSERT OR UPDATE trigger, that modifies NEW as follows:
BEGIN
NEW.last_edit_date := current_timestamp;
RETURN NEW;
END;
I have a trigger function that copy row of unique values to another table on update or insert that ALMOST work.
The trigger should only insert a new row to the sample table if the number don't exist in it before. Atm. it insert a new row to the sample table with the value NULL if the number already exist in the table. I dont want it to do anything if maintbl.number = sample.nb_main
EDIT: sample table and sample data
CREATE TABLE schema.main(
sid SERIAL NOT NULL,
number INTEGER,
CONSTRAINT sid_pk PRIMARY KEY (sid)
)
CREATE TABLE schema.sample(
gid SERIAL NOT NULL,
nb_main INTEGER,
CONSTRAINT gid_pk PRIMARY KEY (gid)
Example and desired result
schema.main schema.sample
number nb_main
234233 234233
234234 555555
234234
555555
555555
CREATE OR REPLACE FUNCTION schema.update_number()
RETURNS trigger AS
$BODY$
BEGIN
INSERT INTO schema.sample(
nb_main)
SELECT DISTINCT(maintbl.number)
FROM schema.maintbl
WHERE NOT EXISTS (
SELECT nb_main FROM schema.sample WHERE maintbl.number = sample.nb_main);
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION schema.update_number()
OWNER TO postgres;
CREATE TRIGGER update_number
AFTER INSERT OR UPDATE
ON schema.maintbl
FOR EACH ROW
EXECUTE PROCEDURE schema.update_number();
I just found out that my select query is probably wrong, if I run SELECT query by itself it return one row 'NULL' but i should not?
SELECT DISTINCT(maintbl.number)
FROM schema.maintbl
WHERE NOT EXISTS (
SELECT nb_main FROM schema.sample WHERE maintbl.number = sample.nb_main);
Any good advice?
Best
If I understood correctly, you wish to append to schema.sample a number that has been inserted or updated in schema.maintbl, right?
CREATE OR REPLACE FUNCTION schema.update_number()
RETURNS trigger AS
$BODY$
BEGIN
IF (SELECT COUNT(*) FROM schema.sample WHERE number = NEW.number) = 0 THEN
INSERT INTO schema.sample(nb_main) VALUES (NEW.number);
END IF;
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql VOLATILE;
Is it possible to dynamically change column values in NEW with a Trigger Function?
Triggers:
CREATE TRIGGER lowercase_username_on_insert_trigger BEFORE INSERT OR UPDATE ON users
FOR EACH ROW EXECUTE PROCEDURE lowercase_on_insert('username');
CREATE TRIGGER lowercase_email_on_insert_trigger BEFORE INSERT OR UPDATE ON users
FOR EACH ROW EXECUTE PROCEDURE lowercase_on_insert('email');
Trigger Function:
CREATE OR REPLACE FUNCTION lowercase_on_insert()
RETURNS trigger
AS $lowercase_on_insert$
BEGIN
-- e.g., NEW.username = LOWER(NEW.username)
-- -OR- NEW.email = LOWER(NEW.email)
EXECUTE FORMAT('NEW.%s = LOWER(NEW.%s);', TG_ARGV[0], TG_ARGV[0]);
RETURN NEW;
END
$lowercase_on_insert$ LANGUAGE plpgsql;
I get an ERROR: syntax error at or new "NEW" whenever I run an INSERT.
This is my table:
CREATE TABLE users (
id BIGSERIAL PRIMARY KEY,
username VARCHAR(55) NOT NULL UNIQUE,
email VARCHAR(120) NOT NULL UNIQUE
);
Change your Trigger function as below
CREATE OR REPLACE FUNCTION lowercase() RETURNS trigger AS $$
BEGIN
NEW.username = LOWER(NEW.username);
NEW.email = LOWER(NEW.email);
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
and assign
CREATE TRIGGER tgrr BEFORE INSERT OR UPDATE ON users
FOR EACH ROW EXECUTE PROCEDURE lowercase();
OR
You can directly apply lower() function in Insert/Update like this
insert into users(username,email) values (lower('Jerry'),lower('JeRRY#mail.COM'));
update users set username=lower('JERRY'),email=lower('JERRY#MAIL.COM') where id =1