I am trying to create a table that logs all inserts in the author table. Here is the author table, and the Audit_log Table:
CREATE TABLE Author(AuthorID INT PRIMARY KEY NOT NULL,
last_name CHAR(20),
first_name CHAR(20));
CREATE TABLE Audit_Log(Action_ID INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
table_name Char(40),
action_name Char(6),
Date_Time DATETIME DEFAULT CURRENT_TIMESTAMP);
Here is the simple trigger.
DELIMITER $$
CREATE TRIGGER Author_Trigger AFTER INSERT
ON Author
FOR EACH ROW BEGIN
INSERT INTO Audit_Log VALUES('Author', 'INSERT', CURRENT_TIMESTAMP);
END $$
DELIMITER ;
However, when I cause the trigger to occur by inserting into the author table, it says that the columns do not match row 1. How come my Primary key does not get auto generated, despite having the AUTO_INCREMENT Constraint?
How can I get this trigger to generate the primary key?
Basically MySQL thinks that 'Author' is being inserted as the PRIMARY KEY (Action_ID). What you can do to avoid this is specify wich attribute correspond to wich element of the INSERT query. This should work :)
DELIMITER $$
CREATE TRIGGER Author_Trigger AFTER INSERT
ON Author
FOR EACH ROW BEGIN
INSERT INTO Audit_Log(table_name, action_name, Date_Time)
VALUES('Author', 'INSERT', CURRENT_TIMESTAMP);
END $$
DELIMITER ;
For the value to autoincrement, since you do not have defined the data you must insert and place the autoincremental, it does not take it, so the first value is null and through this null it will autoincrement.
DELIMITER $$
CREATE TRIGGER Author_Trigger AFTER INSERT
ON Author
FOR EACH ROW BEGIN
INSERT INTO Audit_Log VALUES(null,'Author', 'INSERT', CURRENT_TIMESTAMP);
END $$
DELIMITER ;
Related
in my simple application I would like to create a view in order to allow users filling data of my db.
Here a little example of my data
CREATE TABLE specie
(
specie_id INT PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
nome_comune TEXT UNIQUE,
nome_scientifico TEXT UNIQUE
);
CREATE TABLE rilevatore
(
rilevatore_id INT PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
nome_cognome TEXT UNIQUE,
telefono INTEGER,
email TEXT,
ente_appartenenza TEXT
);
CREATE TABLE evento_investimento
(
evento_id INT PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
data DATE,
ora TIME WITHOUT TIME ZONE,
rilevatore_id INT REFERENCES rilevatore (rilevatore_id),
specie_id INT REFERENCES specie(specie_id),
);
This is the VIEW I created
CREATE VIEW investimenti_vista AS
SELECT
evento_investimento.evento_id,
evento_investimento.ora,
evento_investimento.data,
rilevatore.nome_cognome,
rilevatore.telefono,
rilevatore.email,
rilevatore.ente_appartenenza,
specie.nome_comune,
specie.nome_scientifico
from
evento_investimento
JOIN specie ON evento_investimento.specie_id = specie.specie_id
JOIN rilevatore ON evento_investimento.rilevatore_id = rilevatore.rilevatore_id;
When I attempt to fill the data I receive an error from postgres since view generated from different tables aren't updatable by default.
Thus, I implemetend the following trigger to overcome this issue.
CREATE OR REPLACE FUNCTION inserimento_vista() RETURNS trigger AS $$
BEGIN
INSERT INTO evento_investimento (data,ora)
VALUES (NEW.data,NEW.ora);
INSERT INTO rilevatore (nome_cognome, telefono, email, ente_appartenenza)
VALUES (NEW.nome_cognome, NEW.telefono, NEW.email, NEW.ente_appartenenza);
INSERT INTO specie (nome_comune, nome_scientifico)
VALUES (NEW.nome_comune, NEW.nome_scientifico);
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
create trigger inserimento_vista_trg
instead of insert on investimenti_vista for each row EXECUTE procedure inserimento_vista();
However this is not working due to unique contraints I have in the rilevatore and specie tables. How I can solve this?
Thanks
You might try to check for the existence of the conflicting values like this:
CREATE OR REPLACE FUNCTION inserimento_vista() RETURNS trigger AS $$
BEGIN
INSERT INTO evento_investimento (data,ora)
VALUES (NEW.data,NEW.ora);
if not exists(select * from rilevatore where rilevatore.nome_cognome=new.nome_cognome) then
INSERT INTO rilevatore (nome_cognome, telefono, email, ente_appartenenza)
VALUES (NEW.nome_cognome, NEW.telefono, NEW.email, NEW.ente_appartenenza);
end if;
if not exists(select * from specie where specie.nome_comune=new.nome_comune) then
INSERT INTO specie (nome_comune, nome_scientifico)
VALUES (NEW.nome_comune, NEW.nome_scientifico);
end if;
RETURN NEW;
END;
$$ LANGUAGE plpgsql;
You might want to add to this an update the specie and/or rilevatore tables with the non-conflicting values but that's up to you :-)
I would like to add a constraint that will check values from related table.
I have 3 tables:
CREATE TABLE somethink_usr_rel (
user_id BIGINT NOT NULL,
stomethink_id BIGINT NOT NULL
);
CREATE TABLE usr (
id BIGINT NOT NULL,
role_id BIGINT NOT NULL
);
CREATE TABLE role (
id BIGINT NOT NULL,
type BIGINT NOT NULL
);
(If you want me to put constraint with FK let me know.)
I want to add a constraint to somethink_usr_rel that checks type in role ("two tables away"), e.g.:
ALTER TABLE somethink_usr_rel
ADD CONSTRAINT CH_sm_usr_type_check
CHECK (usr.role.type = 'SOME_ENUM');
I tried to do this with JOINs but didn't succeed. Any idea how to achieve it?
CHECK constraints cannot currently reference other tables. The manual:
Currently, CHECK expressions cannot contain subqueries nor refer to
variables other than columns of the current row.
One way is to use a trigger like demonstrated by #Wolph.
A clean solution without triggers: add redundant columns and include them in FOREIGN KEY constraints, which are the first choice to enforce referential integrity. Related answer on dba.SE with detailed instructions:
Enforcing constraints “two tables away”
Another option would be to "fake" an IMMUTABLE function doing the check and use that in a CHECK constraint. Postgres will allow this, but be aware of possible caveats. Best make that a NOT VALID constraint. See:
Disable all constraints and table checks while restoring a dump
A CHECK constraint is not an option if you need joins. You can create a trigger which raises an error instead.
Have a look at this example: http://www.postgresql.org/docs/9.1/static/plpgsql-trigger.html#PLPGSQL-TRIGGER-EXAMPLE
CREATE TABLE emp (
empname text,
salary integer,
last_date timestamp,
last_user text
);
CREATE FUNCTION emp_stamp() RETURNS trigger AS $emp_stamp$
BEGIN
-- Check that empname and salary are given
IF NEW.empname IS NULL THEN
RAISE EXCEPTION 'empname cannot be null';
END IF;
IF NEW.salary IS NULL THEN
RAISE EXCEPTION '% cannot have null salary', NEW.empname;
END IF;
-- Who works for us when she must pay for it?
IF NEW.salary < 0 THEN
RAISE EXCEPTION '% cannot have a negative salary', NEW.empname;
END IF;
-- Remember who changed the payroll when
NEW.last_date := current_timestamp;
NEW.last_user := current_user;
RETURN NEW;
END;
$emp_stamp$ LANGUAGE plpgsql;
CREATE TRIGGER emp_stamp BEFORE INSERT OR UPDATE ON emp
FOR EACH ROW EXECUTE PROCEDURE emp_stamp();
...i did it so (nazwa=user name, firma = company name) :
CREATE TABLE users
(
id bigserial CONSTRAINT firstkey PRIMARY KEY,
nazwa character varying(20),
firma character varying(50)
);
CREATE TABLE test
(
id bigserial CONSTRAINT firstkey PRIMARY KEY,
firma character varying(50),
towar character varying(20),
nazwisko character varying(20)
);
ALTER TABLE public.test ENABLE ROW LEVEL SECURITY;
CREATE OR REPLACE FUNCTION whoIAM3() RETURNS varchar(50) as $$
declare
result varchar(50);
BEGIN
select into result users.firma from users where users.nazwa = current_user;
return result;
END;
$$ LANGUAGE plpgsql;
CREATE POLICY user_policy ON public.test
USING (firma = whoIAM3());
CREATE FUNCTION test_trigger_function()
RETURNS trigger AS $$
BEGIN
NEW.firma:=whoIam3();
return NEW;
END
$$ LANGUAGE 'plpgsql'
CREATE TRIGGER test_trigger_insert BEFORE INSERT ON test FOR EACH ROW EXECUTE PROCEDURE test_trigger_function();
I'm try to create table with clever sequence generator for using this insert-strucure:
insert into SOMEUSERS (SOMEUSERS_NAME, SOMEUSERS_PASSWORD)
values ('Artem', 'PracTimPatie');
instead of this:
insert into SOMEUSERS (SOMEUSERS_ID, SOMEUSERS_NAME, SOMEUSERS_PASSWORD)
values (2, 'Artem', 'PracTimPatie');
or this structure:
insert into SOMEUSERS (SOMEUSERS_ID, SOMEUSERS_NAME, SOMEUSERS_PASSWORD)
values (GEN_ID_SOMEUSERS.nextval, 'Artem', 'PracTimPatie');
When I executing the following sql script:
create sequence gen_id_someUsers START WITH 1 INCREMENT BY 1 NOCACHE NOCYCLE;
CREATE TABLE loc_db.someUsers
( someUsers_id number(10) DEFAULT gen_id_someUsers.NEXTVAL NOT NULL, --because of this row
someUsers_name varchar2(50) NOT NULL,
someUsers_password varchar2(50),
CONSTRAINT someUsers_pk PRIMARY KEY (someUsers_id)
);
the following notice is given to me:
Error report - SQL Error: ORA-00984: column not allowed here
00984. 00000 - "column not allowed here"
For clarity, said that in this case:
...
CREATE TABLE loc_db.someUsers
( someUsers_id number(10) NOT NULL, --correct this row
...
Sequence GEN_ID_SOMEUSERS created.
Table LOC_DB.SOMEUSERS created.
How can I configure comfortable sequence generator?
(in case of PostgreSQL too. If possible with no trigger(as easily as possible)
Oracle 12c introduces Identity columns:
CREATE TABLE SOMEUSERS (
SOMEUSERS_ID NUMBER(10) GENERATED ALWAYS AS IDENTITY
CONSTRAINT SOMEUSERS__SOMEUSERS_ID__PK PRIMARY KEY,
SOMEUSERS_NAME VARCHAR2(50)
CONSTRAINT SOMEUSERS__SOMEUSERS_NAME__NN NOT NULL,
SOMEUSERS_PASSWORD VARCHAR2(50)
);
If you want to do it in earlier versions then you will need a trigger and a sequence:
CREATE TABLE SOMEUSERS (
SOMEUSERS_ID NUMBER(10)
CONSTRAINT SOMEUSERS__SOMEUSERS_ID__PK PRIMARY KEY,
SOMEUSERS_NAME VARCHAR2(50)
CONSTRAINT SOMEUSERS__SOMEUSERS_NAME__NN NOT NULL,
SOMEUSERS_PASSWORD VARCHAR2(50)
);
/
CREATE SEQUENCE gen_id_someUsers START WITH 1 INCREMENT BY 1 NOCACHE NOCYCLE;
/
CREATE OR REPLACE TRIGGER SOMEUSERS__ID__TRG
BEFORE INSERT ON SOMEUSERS
FOR EACH ROW
BEGIN
:new.SOMEUSERS_ID := gen_id_someUsers.NEXTVAL;
END;
/
You can then just do (either with the identity column or the trigger combined with your sequence):
INSERT INTO SOMEUSERS (
SOMEUSERS_NAME,
SOMEUSERS_PASSWORD
) VALUES (
'Name',
'Password'
);
In postgres just use a serial like this:
CREATE TABLE SOMEUSERS (
SOMEUSERS_ID serial NOT NULL,
SOMEUSERS_NAME text,
SOMEUSERS_PASSWORD text
);
Your insert statement is then easy as:
INSERT INTO SOMEUSERS (SOMEUSERS_NAME, SOMEUSERS_PASSWORD)
values ('Artem', 'PracTimPatie');
If you wanna query the sequence you can just query it like any other relation.
Other answers have addressed postgreSQL and Oracle 12c, so I'll address Oracle 11.2 or earlier here.
From the 11.1 SQL Reference Manual:
DEFAULT
The DEFAULT clause lets you specify a value to be assigned to the column if a subsequent INSERT statement omits a value for the column. The datatype of the expression must match the datatype of the column. The column must also be long enough to hold this expression.
The DEFAULT expression can include any SQL function as long as the function does not return a literal argument, a column reference, or a nested function invocation.
Restriction on Default Column Values
A DEFAULT expression cannot contain references to PL/SQL functions or to other columns, the pseudocolumns CURRVAL, NEXTVAL, LEVEL, PRIOR, and ROWNUM, or date constants that are not fully specified.
(Emphasis mine)
So since you can't put sequence.NEXTVAL in as a DEFAULT value you're basically going to have to use a trigger:
CREATE OR REPLACE TRIGGER SOMEUSERS_BI
BEFORE INSERT
ON LOC_DB.SOMEUSERS
FOR EACH ROW
BEGIN
IF :NEW.SOMEUSERS_ID THEN
:NEW.SOMEUSERS_ID := GEN_ID_SOMEUSERS.NEXTVAL;
END IF;
END SOMEUSERS_BI;
In my experience there is no reliable alternative to using a trigger such as this in Oracle 11.2 or earlier.
Best of luck.
I'm using table inheritance in postgres, but the trigger I'm using to partition data into the child tables isn't quite behaving right. For example, this query returns nil, but I would like it to return the id of the new record.
INSERT INTO flags (flaggable_id, flaggable_type)
VALUES (233, 'Thank')
RETURNING id;
If I change the return value of the trigger function from NULL to NEW, I get the desired RETURNING behavior, but then two identical rows are inserted in the database. This makes sense, since a non-null return value from the trigger function causes the original INSERT statement execute, whereas returning NULL causes the statement to halt execution. A unique index might halt the second insertion, but would probably raise an error.
Any ideas how to make the INSERT with RETURNING work properly with a trigger like this?
CREATE TABLE flags (
id integer NOT NULL,
flaggable_type character varying(255) NOT NULL,
flaggable_id integer NOT NULL,
body text
);
ALTER TABLE ONLY flags
ADD CONSTRAINT flags_pkey PRIMARY KEY (id);
CREATE TABLE "comment_flags" (
CHECK ("flaggable_type" = 'Comment'),
PRIMARY KEY ("id"),
FOREIGN KEY ("flaggable_id") REFERENCES "comments"("id")
) INHERITS ("flags");
CREATE TABLE "profile_flags" (
CHECK ("flaggable_type" = 'Profile'),
PRIMARY KEY ("id"),
FOREIGN KEY ("flaggable_id") REFERENCES "profiles"("id")
) INHERITS ("flags");
CREATE OR REPLACE FUNCTION flag_insert_trigger_fun() RETURNS TRIGGER AS $BODY$
BEGIN
IF (NEW."flaggable_type" = 'Comment') THEN
INSERT INTO comment_flags VALUES (NEW.*);
ELSIF (NEW."flaggable_type" = 'Profile') THEN
INSERT INTO profile_flags VALUES (NEW.*);
ELSE
RAISE EXCEPTION 'Wrong "flaggable_type"="%", fix flag_insert_trigger_fun() function', NEW."flaggable_type";
END IF;
RETURN NULL;
END; $BODY$ LANGUAGE plpgsql;
CREATE TRIGGER flag_insert_trigger
BEFORE INSERT ON flags
FOR EACH ROW EXECUTE PROCEDURE flag_insert_trigger_fun();
The only workaround I found, is to create a view for the base table & use INSTEAD OF triggers on that view:
CREATE TABLE flags_base (
id integer NOT NULL,
flaggable_type character varying(255) NOT NULL,
flaggable_id integer NOT NULL,
body text
);
ALTER TABLE ONLY flags_base
ADD CONSTRAINT flags_base_pkey PRIMARY KEY (id);
CREATE TABLE "comment_flags" (
CHECK ("flaggable_type" = 'Comment'),
PRIMARY KEY ("id")
) INHERITS ("flags_base");
CREATE TABLE "profile_flags" (
CHECK ("flaggable_type" = 'Profile'),
PRIMARY KEY ("id")
) INHERITS ("flags_base");
CREATE OR REPLACE VIEW flags AS SELECT * FROM flags_base;
CREATE OR REPLACE FUNCTION flag_insert_trigger_fun() RETURNS TRIGGER AS $BODY$
BEGIN
IF (NEW."flaggable_type" = 'Comment') THEN
INSERT INTO comment_flags VALUES (NEW.*);
ELSIF (NEW."flaggable_type" = 'Profile') THEN
INSERT INTO profile_flags VALUES (NEW.*);
ELSE
RAISE EXCEPTION 'Wrong "flaggable_type"="%", fix flag_insert_trigger_fun() function', NEW."flaggable_type";
END IF;
RETURN NEW;
END; $BODY$ LANGUAGE plpgsql;
CREATE TRIGGER flag_insert_trigger
INSTEAD OF INSERT ON flags
FOR EACH ROW EXECUTE PROCEDURE flag_insert_trigger_fun();
But this way you must supply the id field on each insertion (even if flags_base's primary key has a default value / is a serial), so you must prepare your insert trigger to fix NEW.id if it is a NULL.
UPDATE: It seems views' columns can have a default values too, set with
ALTER VIEW [ IF EXISTS ] name ALTER [ COLUMN ] column_name SET DEFAULT expression
which is only used in views have an insert/update rule/trigger.
http://www.postgresql.org/docs/9.3/static/sql-alterview.html
#pozs provided a correct answer but didn't quite provide the code for a full working implementation. I tried to include the code in an edit on his question, but it was not accepted. He instead suggested yet another approach, which looks cleaner, but may have some drawbacks (in the case where you re-use your trigger function elsewhere).
Including my solution here for reference:
CREATE TABLE base_flags (
id integer NOT NULL,
flaggable_type character varying(255) NOT NULL,
flaggable_id integer NOT NULL,
body text
);
ALTER TABLE ONLY base_flags
ADD CONSTRAINT base_flags_pkey PRIMARY KEY (id);
CREATE SEQUENCE base_flags_id_seq
START WITH 1
INCREMENT BY 1
NO MINVALUE
NO MAXVALUE
CACHE 1;
ALTER SEQUENCE base_flags_id_seq OWNED BY base_flags.id;
CREATE OR REPLACE VIEW flags AS SELECT * FROM base_flags;
CREATE TABLE "comment_flags" (
CHECK ("flaggable_type" = 'Comment'),
PRIMARY KEY ("id"),
FOREIGN KEY ("flaggable_id") REFERENCES "comments"("id")
) INHERITS ("flags");
CREATE TABLE "profile_flags" (
CHECK ("flaggable_type" = 'Profile'),
PRIMARY KEY ("id"),
FOREIGN KEY ("flaggable_id") REFERENCES "profiles"("id")
) INHERITS ("flags");
CREATE OR REPLACE FUNCTION flag_insert_trigger_fun() RETURNS TRIGGER AS $BODY$
BEGIN
IF NEW.id IS NULL THEN
NEW.id := nextval('base_flags_id_seq');
END IF;
IF (NEW."flaggable_type" = 'Comment') THEN
INSERT INTO comment_flags VALUES (NEW.*);
ELSIF (NEW."flaggable_type" = 'Profile') THEN
INSERT INTO profile_flags VALUES (NEW.*);
ELSE
RAISE EXCEPTION 'Wrong "flaggable_type"="%", fix flag_insert_trigger_fun() function', NEW."flaggable_type";
END IF;
RETURN NEW;
END;
$BODY$
LANGUAGE plpgsql;
CREATE TRIGGER flag_insert_trigger
INSTEAD OF INSERT ON base_flags
FOR EACH ROW EXECUTE PROCEDURE flag_insert_trigger_fun();
Learner here in Oracle 11g. I'm having an issue with INSERTing some rows into two tables that are linked by a primary/foreign key relationship.
Basically I create a sequence to start with 1000 and increment by 1.
Then create a 'STORE' table with a ST_ID column
The ST_ID column is linked to the SEQUENCE with a TRIGGER.
Then I have an 'EMPLOYEE' table that has a EST_ID field that is a foreign key to the ST_ID column in the STORE table.
However, when I tried to insert rows I initially got a error saying EST_ID could not be null. So I created a sequence and trigger for EST_ID and now I'm getting an error saying the foreign key constraint is being violated.
I think that was maybe the wrong thing to do. Do I really want E_ID and EST_ID to be identical and how would I get that to happen? With some kind of trigger?
The actual code:
CREATE SEQUENCE "STORSEQ" MINVALUE 1000 MAXVALUE 9999 INCREMENT BY 1 START WITH 1000 NOCACHE NOORDER
NOCYCLE ;
CREATE TABLE "STORE"
( "ST_ID" CHAR(4) NOT NULL ENABLE,
"STADDR_ID" CHAR(4) NOT NULL ENABLE,
CONSTRAINT "STORE_PK" PRIMARY KEY ("ST_ID") ENABLE
) ;
CREATE TABLE "EMPLOYEE"
( "E_ID" CHAR(8) NOT NULL ENABLE,
"EF_NAME" VARCHAR2(20) NOT NULL ENABLE,
"EL_NAME" VARCHAR2(20) NOT NULL ENABLE,
"EST_ID" CHAR(4) NOT NULL ENABLE,
CONSTRAINT "EMPLOYEE_PK" PRIMARY KEY ("E_ID") ENABLE
) ;
alter table "EMPLOYEE" add CONSTRAINT "EMPLOYEE_CON" foreign key ("EST_ID") references
"STORE" ("ST_ID")
/
CREATE OR REPLACE TRIGGER "BI_STORE"
before insert on "STORE"
for each row
begin
if :NEW."ST_ID" is null then
select "STORSEQ".nextval into :NEW."ST_ID" from dual;
end if;
end;
/
At the moment my INSERT code looks like this:
INSERT INTO STORE
(ST_ID, STADDR_ID)
VALUES
(DEFAULT, DEFAULT);
INSERT INTO EMPLOYEE
(EF_NAME, EL_NAME)
VALUES
('James', 'Smith');
When you try to insert data into table that has foreign key reference, it will not get value for id automatically, you need to pass that value.
You can do this:
declare
v_store_id integer;
begin
INSERT INTO STORE (ST_ID, STADDR_ID) VALUES (DEFAULT, DEFAULT)
RETURNING ST_ID INTO v_Store_id;
INSERT INTO EMPLOYEE (EF_NAME, EL_NAME, EST_ID)
VALUES ('James', 'Smith', v_store_id);
end;
You can also insert id in store id table without trigger using this
declare
v_store_id integer;
begin
INSERT INTO STORE (ST_ID, STADDR_ID) VALUES ("STORSEQ".nextval, DEFAULT)
RETURNING ST_ID INTO v_Store_id;
INSERT INTO EMPLOYEE (EF_NAME, EL_NAME, EST_ID)
VALUES ('James', 'Smith', v_store_id);
end