I have a database with a DDL like this:
CREATE TABLE table(
ID INTEGER NOT NULL,
COLUMN1 VARCHAR(50),
PRIMARY KEY (ID)
);
and with ID autoincrementing on insert like this:
CREATE TRIGGER table_BI FOR table BEFORE INSERT AS
BEGIN
NEW.ID = GEN_ID(generator, 1);
END
My problem is when I add a new row with the same value in the column1 as in an already existing row I get two rows with the same values but different ID.
Related
How to alter existing column auto increment in existing DB2-Table?
If you created a table with a normal column, like an id column here:
CREATE TABLE demo_tab
(id int NOT NULL PRIMARY KEY,
col_txt VARCHAR(20)
);
but later you decided to have it like this one with the GENERATED ALWAYS AS IDENTITY clause:
CREATE TABLE demo_tab
(id int NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1 INCREMENT BY 1) PRIMARY KEY,
col_txt VARCHAR(20)
);
use this statement:
ALTER TABLE demo_tab ALTER COLUMN id
SET GENERATED ALWAYS AS IDENTITY (START WITH 1 INCREMENT BY 1);
and do not forget about reorganising the table:
CALL SYSPROC.ADMIN_CMD('REORG TABLE demo_tab');
if you want modify your identityvalue try this
ALTER TABLE yourtable ALTER COLUMN youridentitycomunname RESTART WITH yourcountervalue
Using Postgres, what I would like to achieve is to be able to have many different instrument types, with corresponding [TYPE].instrument tables, which all have a unique ID in the table, but also reference a unique ID in the instrument.master table. I have the following:
create schema instrument
CREATE TABLE instrument.type (
id smallserial NOT NULL,
name text not null,
code text not null,
CONSTRAINT pk_instrument_type PRIMARY KEY (id)
);
ALTER TABLE instrument.type ADD CONSTRAINT unq_instrument_type_code UNIQUE(code);
ALTER TABLE instrument.type ADD CONSTRAINT unq_instrument_type_name UNIQUE(name);
insert into instrument.type (name, code) values ('futures', 'f');
CREATE TABLE instrument.master (
id serial NOT NULL,
type smallint not null references instrument.type (id),
timestamp timestamp with time zone not null,
CONSTRAINT pk_instrument_master PRIMARY KEY (id)
);
CREATE TABLE futures.definition (
id smallserial NOT NULL,
code text not null,
CONSTRAINT pk_futures_definition PRIMARY KEY (id)
);
ALTER TABLE futures.definition ADD CONSTRAINT unq_futures_definition_code UNIQUE(code);
insert into futures.definition (code) values ('ED');
CREATE TABLE futures.instrument (
id smallserial NOT NULL,
master serial not null references instrument.master (id),
definition smallint not null references futures.definition (id),
month smallint not null,
year smallint not null,
CONSTRAINT pk_futures_instrument PRIMARY KEY (id),
check (month >= 1),
check (month <= 12),
check (year >= 1900)
);
ALTER TABLE futures.instrument ADD CONSTRAINT unq_futures_instrument UNIQUE(definition, month, year);
CREATE OR REPLACE FUNCTION trigger_master_futures()
RETURNS trigger AS
$BODY$
BEGIN
insert into instrument.master (type, timestamp)
select id, current_timestamp from instrument.type where code = 'f';
NEW.master := currval('instrument.master_id_seq');
RETURN NEW;
END;
$BODY$
LANGUAGE 'plpgsql' VOLATILE;
create trigger trg_futures_instrument before insert on futures.instrument
for each row
execute procedure trigger_master_futures();
I then test with:
insert into futures.instrument (definition, month, year)
select id, 3, 2015 from futures.definition where code = 'ED';
Everything works almost as I would like it to. The only issue is that somehow, instrument.master.id ends up being one more than futures.instrument.master. I am not sure what I need to do to achieve the behavior I want, which is that whenever an entry is inserted into futures.instrument, an entry should be inserted into instrument.master, and the id entry of the latter should be inserted into the master entry of the former. I actually think it should have failed since the foreign key relationship is violated somehow.
As it turns out, everything was correct. The issue was that in futures.instrument, the type of the master column is serial, and it should have been int.
Well, I have two tables:
CREATE TABLE Temp(
TEMP_ID int IDENTITY(1,1) NOT NULL, ... )
CREATE TABLE TEMP1(
TEMP1_ID int IDENTITY(1,1) NOT NULL,
TEMP_ID int, ... )
they are linked with TEMP_ID foreign key.
In a stored procedure I need to create tons of
Temp and Temp1 rows and update them, so I created a table variable (#TEMP) and I am dealing with it and finally make one big INSERT into Temp. My question is: how can I fill #Temp with correct TEMP_ID's without insert safely from multiple sessions?
you can use Scope_Identity() to find out last inserted row. You can use Output clause to find all newly inserted (or updated) rows.
create table #t1
(
id int primary key identity,
val int
)
Insert into #t1 (val)
output inserted.id, inserted.val
values (10), (20), (30)
I'm trying to generate a random key including current inserting column value in oracle is it possible to create?
CREATE TABLE MY_TABLE
(
KEY VARCHAR2(12) not null,
SITEID varchar2(25) not null,
SITENAME varchar2(50),
CONSTRAINT MY_pk PRIMARY KEY (KEY)
);
INSERT INTO MY_TABLE (KEY, SITEID, SITENAME)
VALUES(('ABCD001'||SITEID), 'HYD001', 'HYDERABADSITE');
It would be better to use a BEFORE TRIGGER to do this. like,
CREATE OR REPLACE
TRIGGER my_table_trigger
BEFORE INSERT ON my_table
FOR EACH ROW
BEGIN
:NEW.KEY := 'ABCD001'||:NEW.siteid;
END;
CREATE TABLE test ( id int PRIMARY KEY , name );
CREATE TABLE test1 ( id integer[] REFERENCES test , rollid int );
ERROR: foreign key constraint "test3_id_fkey" cannot be implemented
DETAIL: Key columns "id" and "id" are of incompatible types: integer[] and integer.
after that I try to another way also
CREATE TABLE test1 ( id integer[] , rollid int);
ALTER TABLE test1 ADD CONSTRAINT foreignkeyarray FOREIGN KEY (id) REFERENCES test;
ERROR: foreign key constraint "fkarray" cannot be implemented
DETAIL: Key columns "id" and "id" are of incompatible types: integer[] and integer.
so I try create a foreign key array means it say error. please tell me anyone?
postgresql version is 9.1.
What you're trying to do simply can't be done. At all. No ifs, no buts.
Create a new table, test1_test, containing two fields, test1_id, test_id. Put the foreign keys as needed on that one, and make test1's id an integer.
Using arrays with foreign element keys is usually a sign of incorrect design. You need to do separate table with one to many relationship.
But technically it is possible. Example of checking array values without triggers. One reusable function with paramethers and dynamic sql. Tested on PostgreSQL 10.5
create schema if not exists test;
CREATE OR REPLACE FUNCTION test.check_foreign_key_array(data anyarray, ref_schema text, ref_table text, ref_column text)
RETURNS BOOL
RETURNS NULL ON NULL INPUT
LANGUAGE plpgsql
AS
$body$
DECLARE
fake_id text;
sql text default format($$
select id::text
from unnest($1) as x(id)
where id is not null
and id not in (select %3$I
from %1$I.%2$I
where %3$I = any($1))
limit 1;
$$, ref_schema, ref_table, ref_column);
BEGIN
EXECUTE sql USING data INTO fake_id;
IF (fake_id IS NOT NULL) THEN
RAISE NOTICE 'Array element value % does not exist in column %.%.%', fake_id, ref_schema, ref_table, ref_column;
RETURN false;
END IF;
RETURN true;
END
$body$;
drop table if exists test.t1, test.t2;
create table test.t1 (
id integer generated by default as identity primary key
);
create table test.t2 (
id integer generated by default as identity primary key,
t1_ids integer[] not null check (test.check_foreign_key_array(t1_ids, 'test', 't1', 'id'))
);
insert into test.t1 (id) values (default), (default), (default); --ok
insert into test.t2 (id, t1_ids) values (default, array[1,2,3]); --ok
insert into test.t2 (id, t1_ids) values (default, array[1,2,3,555]); --error
If you are able to put there just values from test.id, then you can try this:
CREATE OR REPLACE FUNCTION test_trigger() RETURNS trigger
LANGUAGE plpgsql AS $BODY$
DECLARE
val integer;
BEGIN
SELECT id INTO val
FROM (
SELECT UNNEST(id) AS id
FROM test1
) AS q
WHERE id = OLD.id;
IF val IS NULL THEN RETURN OLD;
ELSE
RAISE 'Integrity Constraint Violation: ID "%" in Test1', val USING ERRCODE = '23000';
RETURN NULL;
END IF;
END; $BODY$;
-- DROP TRIGGER test_delete_trigger ON test;
CREATE TRIGGER test_delete_trigger BEFORE DELETE OR UPDATE OF id ON test
FOR EACH ROW EXECUTE PROCEDURE test_trigger();