so here's the thing,I have two tables: apointments(with a single p) and medical_folder and i get this
ERROR: record "new" has no field "cure"
CONTEXT: SQL statement "insert into medical_folder(id,"patient_AMKA",cure,drug_id)
values(new.id,new."patient_AMKA",new.cure,new.drug_id)"
PL/pgSQL function new_medical() line 3 at SQL statement
create trigger example_trigger after insert on apointments
for each row execute procedure new_medical();
create or replace function new_medical()
returns trigger as $$
begin
if apointments.diagnosis is not null then
insert into medical_folder(id,"patient_AMKA",cure,drug_id)
values(new.id,new."patient_AMKA",new.cure,new.drug_id);
return new;
end if;
end;
$$ language plpgsql;
insert into apointments(id,time,"patient_AMKA","doctor_AMKA",diagnosis)
values('30000','2017-05-24 0
07:42:15','4017954515276','6304745877947815701','M3504');
I have checked multiple times and all of my tables and columns are existing
Please help!Thank you!
Table structures are:
create table medical_folder (
id bigInt,
patient bigInt,
cure text,
drug_id bigInt);
create table apointments (
id bigint,
time timestamp without time zone,
"patient_AMKA" bigInt,
"doctor_AMKA" bigInt);
I was facing the same issue.
Change:
values(new.id,new."patient_AMKA",new.cure,new.drug_id);
to:
values(new.id,new."patient_AMKA",new."cure",new."drug_id");
This error means the table apointments (with 1 p) doesn't have a field named cure. The trigger occurs when inserting an apointment, so "new" is an apointment row. Maybe it is part of the diagnosis object?
The values for the second table are not available in the "new" row. You need a way to get and insert them, and using a trigger is not the easiest/clean way to go.
You can have your application do two inserts, one by table, and wrap them in a transaction to ensure they are both committed/rolled back. Another option, which lets you better enforce the data integrity, is to create a stored procedure that takes the values to be inserted in both tables and do the two inserts. You can go as far as forbidding user to write to the tables, effectively leaving the stored procedure the only way to insert the data.
Related
I would like to create a trigger function inside my database which checks, if the newly "inserted" value (max_bid) is at least +1 greater than the largest max_bid value currently in the table.
If this is the case, the max_bid value inside the table should be updated, although not with the newly "inserted" value, but instead it should be increased by 1.
For instance, if max_bid is 10 and the newly "inserted" max_bid is 20, the max_bid value inside the table should be increased by +1 (in this case 11).
I tried to do it with a trigger, but unfortunatelly it doesn't work. Please help me to solve this problem.
Here is my code:
CREATE TABLE bidtable (
mail_buyer VARCHAR(80) NOT NULL,
auction_id INTEGER NOT NULL,
max_bid INTEGER,
PRIMARY KEY (mail_buyer),
);
CREATE OR REPLACE FUNCTION max_bid()
RETURNS TRIGGER LANGUAGE PLPGSQL AS $$
DECLARE
current_maxbid INTEGER;
BEGIN
SELECT MAX(max_bid) INTO current_maxbid
FROM bidtable WHERE NEW.auction_id = OLD.auction_id;
IF (NEW.max_bid < (current_maxbid + 1)) THEN
RAISE EXCEPTION 'error';
RETURN NULL;
END IF;
UPDATE bidtable SET max_bid = (current_maxbid + 1)
WHERE NEW.auction_id = OLD.auction_id
AND NEW.mail_buyer = OLD.mail_buyer;
RETURN NEW;
END;
$$;
CREATE OR REPLACE TRIGGER max_bid_trigger
BEFORE INSERT
ON bidtable
FOR EACH ROW
EXECUTE PROCEDURE max_bid();
Thank you very much for your help.
In a trigger function that is called for an INSERT operation the OLD implicit record variable is null, which is probably the cause of "unfortunately it doesn't work".
Trigger function
In a case like this there is a much easier solution. First of all, disregard the value for max_bid upon input because you require a specific value in all cases. Instead, you are going to set it to that specific value in the function. The trigger function can then be simplified to:
CREATE OR REPLACE FUNCTION set_max_bid() -- Function name different from column name
RETURNS TRIGGER LANGUAGE PLPGSQL AS $$
BEGIN
SELECT MAX(max_bid) + 1 INTO NEW.max_bid
FROM bidtable
WHERE auction_id = NEW.auction_id;
RETURN NEW;
END; $$;
That's all there is to it for the trigger function. Update the trigger to the new function name and it should work.
Concurrency
As several comments to your question pointed out, you run the risk of getting duplicates. This will currently not generate an error because you do not have an appropriate constraint on your table. Avoiding duplicates requires a table constraint like:
UNIQUE (auction_id, max_bid)
You cannot deal with any concurrency issue in the trigger function because the INSERT operation will take place after the trigger function completes with a RETURN NEW statement. What would be the most appropriate way to deal with this depends on your application. Your options are table locking to block any concurrent inserts, or looping in a function until the insert succeeds.
Avoid the concurrency issue altogether
If you can change the structure of the bidtable table, you can get rid of the whole concurrency issue by changing your business logic to not require the max_bid column. The max_bid column appears to indicate the order in which bids were placed for each auction_id. If that is the case then you could add a serial column to your table and use that to indicate order of bids being placed (for all auctions). That serial column could then also be the PRIMARY KEY to make your table more agile (no indexing on a large text column). The table would look something like this:
CREATE TABLE bidtable (
id SERIAL PRIMARY KEY,
mail_buyer VARCHAR(80) NOT NULL,
auction_id INTEGER NOT NULL
);
You can drop your trigger and trigger function and just depend on the proper id value being supplied by the system.
The bids for a specific action can then be extracted using a straightforward SELECT:
SELECT id, mail_buyer
FROM bidtable
WHERE auction_id = xxx
ORDER BY id;
If you require a max_bid-like value (the id values increment over the full set of auctions), you can use a simple window function:
SELECT mail_buyer, row_number() AS max_bid OVER (PARTITION BY auction_id ORDER BY id)
FROM bidtable
WHERE auction_id = xxx;
In PostgreSQL I have this table... (there is a primary key in the most left side "timestamp02" which is not shown in this image, please don't bother, its not important for the purpose of this question)
in the table above, all columns are entered via queries, except the "time_index" which I would like to be filled automatically via a trigger each time each row is filled.
This is the code to create the same table (without any value) so everyone could create it using the Postgre SQL query panel.
CREATE TABLE table_ebscb_spa_log02
(
pcnum smallint,
timestamp02 timestamp with time zone NOT NULL DEFAULT now(),
fn_name character varying,
"time" time without time zone,
time_elapse character varying,
time_type character varying,
time_index real,
CONSTRAINT table_ebscb_spa_log02_pkey PRIMARY KEY (timestamp02)
)
WITH (
OIDS=FALSE
);
ALTER TABLE table_ebscb_spa_log02
OWNER TO postgres;
What I would like the trigger to do is:
INSERT a number in the "time_index" column based on the INSERTed values of the "fn_name" and "time_type" columns in each row.
If both ("fn_name" and "time_type") do a combination (eg. Check Mails - Start) that doesn't exist in any row before (above), then INSERT 1 in the "time_index" column,
Elif both ("fn_name" and "time_type") do a combination that does exist in some row before (above), then INSERT the number following the one before(above) in the "time_index" column.
(pls look at the example table image, this trigger will produce every red highlighted square on it)
I have watch many, PostgreSQL tutorial videos, read many manuals, including these
http://www.postgresql.org/docs/9.4/static/sql-createtrigger.html
http://www.postgresql.org/docs/9.4/static/plpgsql-trigger.html
without any result.
I have tried so far this to create the function:
CREATE OR REPLACE FUNCTION on_ai_myTable() RETURNS TRIGGER AS $$
DECLARE
t_ix real;
n int;
BEGIN
IF NEW.time_type = 'Start' THEN
SELECT t.time_index FROM table_ebscb_spa_log02 t WHERE t.fn_name = NEW.fn_name AND t.time_type = 'Start' ORDER BY t.timestamp02 DESC LIMIT 1 INTO t_ix;
GET DIAGNOSTICS n = ROW_COUNT;
IF (n = 0) THEN
t_ix = 1;
ELSE
t_ix = t_ix + 1;
END IF;
END IF;
NEW.time_index = t_ix;
return NEW;
END
$$
LANGUAGE plpgsql;
And this to create the query:
CREATE TRIGGER on_ai_myTable
AFTER INSERT ON table_ebscb_spa_log02
FOR EACH ROW
EXECUTE PROCEDURE on_ai_myTable();
Then when I manually insert the values in the table, nothing change (no error message) time_index column just remain empty, what am I doing wrong???
Please some good PostgreSQL fellow programmer could give me a hand, I really have come to a death point in this task, I have any more ideas.
Thanks in advance
In an AFTER INSERT trigger, any changes you make to NEW.time_index will be ignored. The record is already inserted at this point; it's too late to modify it.
Create the trigger as BEFORE INSERT instead.
TRIGEER-->To get a column value from one table to other table when i insert values?
I am having two tables(customer_details and loan_balance).
What i need is, I must get the column (custid)of customer_details table to the loan_balance table when i insert the data into the loan_balance table.
This is the full set up of my query : SQL FIDDLE
So i need a trigger to be raised and the data should be updated automatically without dynamic insertion of custid.
Postgres has an unconventional way of creating triggers:
create a function that returns type trigger and return the NEW row record
create a trigger that executes the function
Here's the code you need:
CREATE FUNCTION synch_custid_proc()
RETURNS trigger AS $$
BEGIN
NEW.custid = (
select max(custid)
from customer_details
where creditid = NEW.creditid
);
RETURN NEW;
END;
$$ LANGUAGE plpgsql
CREATE TRIGGER synch_custid_trig
BEFORE INSERT ON loan_amount
FOR EACH ROW
EXECUTE PROCEDURE synch_custid_proc();
I chosen to select max(custid) rather than simply custid when finding the value in case there are multiple rows that match. You might have to adjust this logic to suit your data.
See a live demo on SQLFiddle
I am writing a trigger in plpgsql for Postgres 9.1. I need to be able to capture the column names that were issued in the SET clause of an UPDATE so I can record the specified action in an audit table. The examples in the Postgres documentation are simple and inadequate for my needs. I have searched the internet for days and I am unable to find any other examples that try to achieve what I want to do here.
I am on a tight schedule to resolve this soon. I don't know Tcl so pl/Tcl is out of the question for me at this point. pl/Perl may work but I don't know where to start with it. Also I wanted to find a way to accomplish this in pl/pgsql if at all possible for portability and maintenance. If someone can recommend a pl/Perl solution to this I would be grateful.
Here is the table structure of the target table that will be audited:
Note: There are many other columns in the record table but I have not listed them here in order to keep things simple. But the trigger should be able to record changes to any of the columns in the row.
CREATE TABLE record (
record_id integer NOT NULL PRIMARY KEY,
lastname text,
frstname text,
dob date,
created timestamp default NOW(),
created_by integer,
inactive boolean default false
);
create sequence record_record_id_seq;
alter table record alter record_id set default nextval('record_record_id_seq');
Here is my audit table:
CREATE TABLE record_audit (
id integer NOT NULL PRIMARY KEY,
operation char(1) NOT NULL, -- U, I or D
source_column text,
source_id integer,
old_value text,
new_value text,
created_date timestamp default now(),
created_by integer
);
create sequence record_audit_id_seq;
alter table record_audit alter id set default nextval('record_audit_id_seq');
My goal is to record INSERTS and UPDATES to the record table in the record_audit table that will detail not only what the target record_id was (source_id) that was updated and what column was updated (source_column), but also the old_value and the new_value of the column.
I understand that the column values will have to be CAST() to a type of text. I believe I can access the old_value and new_value by accessing NEW and OLD but I am having difficulty figuring out how to obtain the column names used in the SET clause of the UPDATE query. I need the trigger to add a new record to the record_audit table for every column specified in the SET clause. Note, there are not DELETE actions as records are simply UPDATED to inactive = 't' (and thus recorded in the audit table)
Here is my trigger so far (obviously incomplete). Please forgive me, I am learning pl/pgsql as I go.
-- Trigger function for record_audit table
CREATE OR REPLACE FUNCTION audit_record() RETURNS TRIGER AS $$
DECLARE
insert_table text;
ref_col text; --how to get the referenced column name??
BEGIN
--
-- Create a new row in record_audit depending on the operation (TG_OP)
--
IF (TG_OP = 'INSERT') THEN
-- old_value and new_value are meaningless for INSERTs. Just record the new ID.
INSERT INTO record_audit
(operation,source_id,created_by)
VALUES
('I', NEW.record_id, NEW.created_by);
ELSIF (TG_OP = 'UPDATE') THEN
FOR i in 1 .. TG_ARGV[0] LOOP
ref_col := TG_ARGV[i].column; -- I know .column doesn't exist but what to use?
INSERT INTO record_audit
(operation, source_column, source_id, old_value, new_value, created_by)
VALUES
('U', ref_col, NEW.record_id, OLD.ref_col, NEW.ref_col, NEW.created_by);
END LOOP;
END IF;
RETURN NULL; -- result is ignored anyway since this is an AFTER trigger
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER record_audit_trig
AFTER INSERT OR UPDATE on record
FOR EACH ROW EXECUTE PROCEDURE audit_record();
Thanks for reading this long and winding question!
you cannot to get this information - not in PL level - probably it is possible in C.
Good enough solution is based on changed fields in records NEW and OLD. You can get list of fields from system tables ~ are related to table that is joined to trigger.
I want to define a trigger in PostgreSQL to check that the inserted row, on a generic table, has the the property: "no other row exists with the same key in the same valid time" (the keys are sequenced keys). In fact, I has already implemented it. But since the trigger has to scan the entire table, now i'm wondering: is there a need for a table-level lock? Or this is managed someway by the PostgreSQL itself?
Here is an example.
In the upcoming PostgreSQL 9.0 I would have defined the table in this way:
CREATE TABLE medicinal_products
(
aic_code CHAR(9), -- sequenced key
full_name VARCHAR(255),
market_time PERIOD,
EXCLUDE USING gist
(aic_code CHECK WITH =,
market_time CHECK WITH &&)
);
but in fact I have been defined it like this:
CREATE TABLE medicinal_products
(
PRIMARY KEY (aic_code, vs),
aic_code CHAR(9), -- sequenced key
full_name VARCHAR(255),
vs DATE NOT NULL,
ve DATE,
CONSTRAINT valid_time_range
CHECK (ve > vs OR ve IS NULL)
);
Then, I have written a trigger that check the costraint: "two distinct medicinal products can have the same code in two different periods, but not in same time".
So the code:
INSERT INTO medicinal_products VALUES ('1','A','2010-01-01','2010-04-01');
INSERT INTO medicinal_products VALUES ('1','A','2010-03-01','2010-06-01');
return an error.
One solution is to have a second table to use for detecting clashes, and populate that with a trigger. Using the schema you added into the question:
CREATE TABLE medicinal_product_date_map(
aic_code char(9) NOT NULL,
applicable_date date NOT NULL,
UNIQUE(aic_code, applicable_date));
(note: this is the second attempt due to misreading your requirement the first time round. hope it's right this time).
Some functions to maintain this table:
CREATE FUNCTION add_medicinal_product_date_range(aic_code_in char(9), start_date date, end_date date)
RETURNS void STRICT VOLATILE LANGUAGE sql AS $$
INSERT INTO medicinal_product_date_map
SELECT $1, $2 + offset
FROM generate_series(0, $3 - $2)
$$;
CREATE FUNCTION clr_medicinal_product_date_range(aic_code_in char(9), start_date date, end_date date)
RETURNS void STRICT VOLATILE LANGUAGE sql AS $$
DELETE FROM medicinal_product_date_map
WHERE aic_code = $1 AND applicable_date BETWEEN $2 AND $3
$$;
And populate the table first time with:
SELECT count(add_medicinal_product_date_range(aic_code, vs, ve))
FROM medicinal_products;
Now create triggers to populate the date map after changes to medicinal_products: after insert calls add_, after update calls clr_ (old values) and add_ (new values), after delete calls clr_.
CREATE FUNCTION sync_medicinal_product_date_map()
RETURNS trigger LANGUAGE plpgsql AS $$
BEGIN
IF TG_OP = 'UPDATE' OR TG_OP = 'DELETE' THEN
PERFORM clr_medicinal_product_date_range(OLD.aic_code, OLD.vs, OLD.ve);
END IF;
IF TG_OP = 'UPDATE' OR TG_OP = 'INSERT' THEN
PERFORM add_medicinal_product_date_range(NEW.aic_code, NEW.vs, NEW.ve);
END IF;
RETURN NULL;
END;
$$;
CREATE TRIGGER sync_date_map
AFTER INSERT OR UPDATE OR DELETE ON medicinal_products
FOR EACH ROW EXECUTE PROCEDURE sync_medicinal_product_date_map();
The uniqueness constraint on medicinal_product_date_map will trap any products being added with the same code on the same day:
steve#steve#[local] =# INSERT INTO medicinal_products VALUES ('1','A','2010-01-01','2010-04-01');
INSERT 0 1
steve#steve#[local] =# INSERT INTO medicinal_products VALUES ('1','A','2010-03-01','2010-06-01');
ERROR: duplicate key value violates unique constraint "medicinal_product_date_map_aic_code_applicable_date_key"
DETAIL: Key (aic_code, applicable_date)=(1 , 2010-03-01) already exists.
CONTEXT: SQL function "add_medicinal_product_date_range" statement 1
SQL statement "SELECT add_medicinal_product_date_range(NEW.aic_code, NEW.vs, NEW.ve)"
PL/pgSQL function "sync_medicinal_product_date_map" line 6 at PERFORM
This depends on the values being checked for having a discrete space- which is why I asked about dates vs timestamps. Although timestamps are, technically, discrete since Postgresql only stores microsecond-resolution, adding an entry to the map table for every microsecond the product is applicable for is not practical.
Having said that, you could probably also get away with something better than a full-table scan to check for overlapping timestamp intervals, with some trickery on looking for only the first interval not after or not before... however, for easy discrete spaces I prefer this approach which IME can also be handy for other things too (e.g. reports that need to quickly find which products are applicable on a certain day).
I also like this approach because it feels right to leverage the database's uniqueness-constraint mechanism this way. Also, I feel it will be more reliable in the context of concurrent updates to the master table: without locking the table against concurrent updates, it would be possible for a validation trigger to see no conflict and allow inserts in two concurrent sessions, that are then seen to conflict when both transaction's effects are visible.
Just a thought, in case the valid time blocks could be coded with a number or something, creating a UNIQUE index on Id+TimeBlock would be blazingly fast and resolve all table lock problems.
It is managed by PostgreSQL itself. On a select it acquires an ACCESS_SHARE lock which means that you can query the table but do not perform updates.
A radical solution which might help you is to use a cache like ehcache or memcached to store the id/timeblock info and not use the postgresql at all. Many can be persisted so they would survive a server restart and they do not exhibit this locking behavior.
Why can't you use a UNIQUE constraint? Will be much faster (it's an index) and easier.