Firstly I created a table like this:
CREATE TABLE "DEPTT_DEMO1"
(
"DEPARTMENT_ID" NUMBER(4,0),
"DEPARTMENT_NAME" VARCHAR2(30 BYTE) CONSTRAINT "DEPT_NAME_NN1" NOT NULL ENABLE,
"MANAGER_ID" NUMBER(6,0),
"LOCATION_ID" NUMBER(4,0),
CONSTRAINT "DEPT_ID_PK1" PRIMARY KEY ("DEPARTMENT_ID")
);
After the table is created, I insert a few rows of data and then created a view like this:
CREATE OR REPLACE VIEW dept_demo_vw1
AS
SELECT DEPARTMENT_ID, DEPARTMENT_NAME, MANAGER_ID, LOCATION_ID
FROM DEPTT_DEMO1;
I create a trigger as well:
CREATE OR REPLACE TRIGGER vw_dept_tri
INSTEAD OF INSERT ON dept_demo_vw1
--declare
BEGIN
UPDATE dept_demo_vw1
SET DEPARTMENT_ID = dept_id.nextval
WHERE DEPARTMENT_ID IS NULL;
END vw_dept_tri;
After this when I try to insert data into the view, it says that the data is inserted, but I can't see any data in my view.
I don't know what you are doing, but you're doing it wrong.
INSTEAD OF trigger you wrote doesn't make much sense. It is instead of INSERT, but you are performing an UPDATE
Moreover, you are updating a view, but you should have been doing it on a table (not a view); that's why it is called "instead of" - instead of inserting into a view, you'd be inserting into a table
DEPTT_DEMO1.DEPARTMENT_ID is a primary key column. It means that it can not accept NULL values
Trigger's WHERE clause says WHERE DEPARTMENT_ID IS NULL; it is never NULL, that's a primary key column
Shortly, you'll have to think it over and do it properly.
Related
Please, help!
I have trigger:
CREATE TRIGGER check_reservation BEFORE INSERT ON order
FOR EACH ROW
DECLARE mistake INTEGER;
BEGIN
SELECT count(*) INTO mistake FROM order join reserving
on id_order = reserving.order_id_order
WHERE reserving.room_num_room=:new.room_num_room
AND (order.reservation_from < :new.reservation_from AND :new.reservation_from < order.reservation_to) OR
(order.reservation_from < :new.reservation_from AND :new.reservation_to < order.reservation_to) OR
(:new.reservation_from <= order.reservation_from AND order.reservation_to <= :new.reservation_to);
IF mistake>0 THEN
raise_application_error(-20001,'reservation already exists');
END IF;
END;
The idea of the trigger is not to allow make a reservation on already booked room. When I run it I had check compiler log error message. How can I change trigger?
I have following tables:
CREATE TABLE order (
id_order CHAR(100) NOT NULL,
reservation_from DATE NOT NULL,
reservation_to DATE NOT NULL,
);
ALTER TABLE order ADD CONSTRAINT order_pk PRIMARY KEY ( id_order );
CREATE TABLE room (
num_room CHAR(100) NOT NULL,
type VARCHAR2(100) NOT NULL,
);
ALTER TABLE room ADD CONSTRAINT room_pk PRIMARY KEY ( num_room );
CREATE TABLE reserving (
room_num_room CHAR(100) NOT NULL,
order_id_order CHAR(100) NOT NULL
);
ALTER TABLE reserving ADD CONSTRAINT reserving_pk PRIMARY KEY ( room_num_room,
order_id_order );
ALTER TABLE reserving
ADD CONSTRAINT reserving_order_fk FOREIGN KEY ( order_id_order )
REFERENCES order ( id_order );
ALTER TABLE reserving
ADD CONSTRAINT reserving_room_fk FOREIGN KEY ( room_num_room )
REFERENCES room ( num_room );
I tried recreating the trigger with the statements above. The statements failed with several errors, it looks as if they were not tested before posting them as question. Please take some time posting a quality question.
Example:
CREATE TABLE room (
num_room CHAR(100) NOT NULL,
type VARCHAR2(100) NOT NULL, << this trailing comma makes this statement fail.
);
After fixing all errors I ran the "CREATE TRIGGER" and it errored out with
PLS-00049: bad bind variable 'NEW.ROOM_NUM_ROOM'
That is because the column ROOM_NUM_ROOM does not exist in the "ORDER" table.
If I remove the reference to 'NEW.ROOM_NUM_ROOM' the trigger compiles successfully.
However, as gsalem pointed out, this will not work because it will raise a mutating table error. In the trigger code you cannot execute DML referencing the table that the trigger is on. There is plenty of documentation on how to avoid mutating table errors.
I have looked over the internet and their solutions wont fix my problem, hence I'm asking for help here to check if there's mistakes in my coding.
I wanted to create a temporary table populated by other source tables and then implement it into the fact table. I have checked if the data type and the parameter is matching or the sequence of the keys but still it's giving me the error
"ORA-02291: integrity constraint (SYSTEM.SYS_C007167) violated -
parent key not found"
Fact Table:
CREATE TABLE DW_ITEMS7364 (
DW_ID int not null,
ManID char(5),
WHID char(5),
STKID char(5),
Profit number,
CONSTRAINT DW_ID PRIMARY KEY (DW_ID),
FOREIGN KEY(ManID) REFERENCES DW_MANUFACTURER7364,
FOREIGN KEY(WHID) REFERENCES DW_WAREHOUSE7364,
FOREIGN KEY(StkID) REFERENCES DW_STOCKITEM7364);
CREATE SEQUENCE seq_items7364 START WITH 101 increment by 1;
CREATE TRIGGER trg_items7364 BEFORE INSERT OR UPDATE ON DW_ITEMS7364
FOR EACH ROW
BEGIN
SELECT seq_items7364.NEXTVAL
INTO :new.DW_ID
FROM dual;
END;
Temporary Table:
CREATE TABLE TEMP_TAB7364 AS( SELECT m.ManID, w.WHID, s.STKID, (s.SellingPrice-s.PurchasePrice) AS "Profit"
FROM MANUFACTURER7364 m LEFT OUTER JOIN STOCKITEM7364 s ON s.ManID = m.ManID
RIGHT OUTER JOIN WAREHOUSE7364 w on s.WHID = w.WHID WHERE s.SELLINGPRICE IS NOT NULL AND s.PURCHASEPRICE IS NOT NULL
);
These are my source tables:
CREATE TABLE MANUFACTURER7364(
ManID char(5),
ManName varchar (25),
CityID char(5) NOT NULL,
PRIMARY KEY(ManID),
FOREIGN KEY(CityID) REFERENCES CITY7364);
CREATE TABLE WAREHOUSE7364(
WHID char(5),
MaxNoOfPallets number,
CostPerPallet number,
SecurityLevel char(1),
FreezerFacilities varchar(10),
QuarantineFacilities varchar(10),
CityID char(5) NOT NULL,
PRIMARY KEY(WHID),
FOREIGN KEY(CityID) REFERENCES CITY7364);
CREATE TABLE STOCKITEM7364(
StkID char(5),
StkName varchar(20),
SellingPrice number,
PurchasePrice number,
ManID char(5) NOT NULL,
WHID char(5) NOT NULL,
PRIMARY KEY(StkID),
FOREIGN KEY(ManID) REFERENCES MANUFACTURER7364,
FOREIGN KEY(WHID) REFERENCES WAREHOUSE7364);
As far as I can tell, nothing of what you posted raises that error.
Additional drawback is the way you chose to create foreign key constraints. If you don't name it, Oracle assigns the name itself and it looks the way you posted it: SYSTEM.SYS_C007167.
SQL> create table test
2 (id_dept number,
3 id_emp number,
4 foreign key (id_dept) references dept (deptno),
5 foreign key (id_emp) references emp (empno));
Table created.
SQL> select constraint_name from user_constraints where table_name = 'TEST';
CONSTRAINT_NAME
------------------------------
SYS_C008172
SYS_C008173
SQL>
When one of these fails, looking at its name you have no idea what went wrong, unless you investigate a little bit more:
SQL> select column_name from user_cons_columns where constraint_name = 'SYS_C008173';
COLUMN_NAME
-----------------------
ID_EMP
SQL>
But, if you name the constraint, it is way simpler:
SQL> create table test
2 (id_dept number,
3 id_emp number,
4 constraint fk_test_dept foreign key (id_dept) references dept (deptno),
5 constraint fk_test_emp foreign key (id_emp) references emp (empno));
Table created.
SQL> select constraint_name from user_constraints where table_name = 'TEST';
CONSTRAINT_NAME
------------------------------
FK_TEST_DEPT
FK_TEST_EMP
SQL>
Another major drawback one notices is what's written in front of the dot, here: SYSTEM.SYS_C007167. Yes, that would be SYSTEM. Shortly, don't do that. Leave SYS and SYSTEM alone; they are powerful, they are special. Why would you take the risk of destroying the database if you (un)intentionally do something hazardous? Create another user, grant required privileges and work in that schema.
If I understood you correctly, once you create that temp table (TEMP_TAB7364), its contents is transferred into the DW_ITEMS7364 and - doing so - you hit the error.
If that's so, what's the purpose of the temp table? Insert directly into the target table and save resources. Will it fail? Of course it will, unless you change the query. How? I don't know - make sure that you don't insert values that don't exist in any of three tables used for enforcing referential integrity.
Though, as you already have the temp table, if it isn't too large, a (relatively) quick & dirty way of finding out which row is responsible for the error can be found with a loop, such as
begin
for cur_r in (select col1, col2, ... from temp_table) loop
begin
insert into target (col1, col2, ...)
values (cur_r.col1, cur_r.col2, ...);
exception
when others then
dbms_output.put_line(sqlerrm ||': '|| cur_r.col1 ||', '||cur_r.col2);
end;
end loop;
end;
The inner BEGIN-END block is here to make sure that the PL/SQL code won't exit at the first error, but will display them all. Then review those values and find the reason that makes your query invalid.
Evening, needing assistance regarding triggers.
Within my development environment I have two tables, one containing employee data (which contains various data errors that will be amended via ALTER TABLE) and the log table.
How do i go about designing a trigger that will update multiple rows contained within the log table such as 'issue_status','status_update_date' when ALTER TABLE sql is used to amend the data contained in the first data table?
-- employee table
CREATE TABLE emp(
emp_id INTEGER NOT NULL,
emp_name VARCHAR(30),
emp_postcode VARCHAR(20),
emp_registered DATE,
CONSTRAINT pk_emp PRIMARY KEY (emp_id));
-- SQL for the log table
CREATE TABLE data_log
(issue_id NUMBER(2) NOT NULL,
table_name VARCHAR2(20),
row_name VARCHAR2(20),
data_error_code NUMBER(2),
issue_desc VARCHAR2(50),
issue_date DATE,
issue_status VARCHAR2(20),
status_update_date DATE);
-- example log insert
INSERT INTO data_log( SELECT DI_SEQ.nextval, 'emp', emp.emp_id, '1', 'emp_name case size not UPPER', SYSDATE, 'un-fixed', '' FROM emp WHERE emp_name != UPPER(emp_name));
This is the example of the issue inserted into the log table. All i want to do is if I update the emp table to set 'emp_name' to Upper the trigger will register this update and change the rows 'issue_status' and 'status_update_date' to 'fixed' and the 'sysdate' of when the change was made
I've done some browsing however i'm still struggling to understand, any literature recommendations would be appreciated also.
Thanks in advance for the assistance.
Note that we don't use ALTER TABLE to update the rows of a table as you have mentioned.We use Update statement. Your trigger should be a BEFORE UPDATE TRIGGER like this.
CREATE OR REPLACE TRIGGER trig_emp_upd BEFORE
UPDATE ON emp
FOR EACH ROW
WHEN ( new.emp_name = upper(old.emp_name) )
BEGIN
UPDATE data_log
SET
issue_status = 'fixed',
status_update_date = SYSDATE
WHERE
row_name =:new.emp_id;
END;
/
I'm having trouble creating a view between two tables, as I'm quite new to SQL. I need to create a view which will show which employees have carried out work as consultants within the past 14 days. The result of the view should also display this kind of layout:
14 day consultancy report
-----------------------------------------------
Employee Helvin Paul worked for 6 hours for factory ltd chargeable £351
The two tables I assume you will need to join together are the Employee table and also the Consultancy table. I will show both below as I have them in a text file from when I was creating these tables:
create table Funtom_employee
(
emp_ID Number(3) primary key,
Emp_firstname varchar2(50) not null,
Emp_surname varchar2(50),
Emp_department Number(2) constraint FK_funtom_dept references
funtom_department,
emp_street varchar2(50),
emp_town varchar2(50),
emp_district varchar2(50),
Emp_grade Number(3) default 4 constraint chk_emp_grd check (Emp_grade between 1 and 9),
Emp_site varchar2(30) default 'LONDON',
constraint FK_funtom_grade funtom_grade references funtom_department
);
create table Funtom_consultancy
(
consultancy_ID Number(3) primary key,
Consultancy_emp Number(3) constraint cns_emp references funtom_employee,
Consultancy_hours Number(4,2) constraint consultancy_check check (Consultancy_hours > 1),
Consultancy_client Number(3) references funtom_customer,
Consultancy_date DATE,
Consultancy_activity Number(3) references funtom_activity
);
Thanks to anyone that can help with this create view and for your time
A view can be created using the CREATE VIEW statement. An example based on your data is listed below.
CREATE VIEW consultancy_report as
select
Funtom_employee.Emp_firstname,
Funtom_consultancy.Consultancy_date,
from
Funtom_employee
join Funtom_consultancy
on Funtom_employee.emp_id = Funtom_consultancy.Consultancy_emp
You can add whatever other fields you need from either table in the select clause of the query. I've demonstrated one field from both tables.
If you want output explicitly as listed in your sample, you will need to concatenate several fields together as one string. Since this feels like a homework question, I will leave that as an exercise for you.
We want to keep the editing history of some table and restore them if necessary. For example, we have following tables. We want to audit the emp table when insert /delete action performed. Besides these, when update on version field happens, we also need to save a copy of related emp_addr records to emp_addr_audit. When users want to roll back to a specif version of one emp, we need to restore the record from emp_audit and emp_addr_audit.
I am thinking to use a trigger to do audit work and a procedure to do restore work. I know the key part is how to maintain the integrity of parent-child tables in audit and restore work. I need some advices. Thanks.
create table emp (
emp_id integer primary key,
version varchar(50)
);
/* Address table */
create table emp_addr (
addr_id integer primary key,
emp_id integer, -- references table emp
line1 varchar(30),
);
/* Audit table for emp table */
create table emp_audit (
operation character(1),
updatetime timestamp,
emp_id integer,
version varchar(50)
);
/* Audit table for emp_addr table */
create table emp_addr_audit (
operation character(1),
addr_id integer,
emp_id integer,
line1 varchar(30),
);
I'd recommend adding id field as a primary key to audit tables, since you need to reference to the emp table when rolling back to it and you also need that emp to reference corresponding version of emp_addr.
So audit table DDLs should look like this:
/* Audit table for emp table */
create table emp_audit (
id bigserial,
operation character(1),
updatetime timestamp,
emp_id integer,
version varchar(50),
CONSTRAINT audit_emp_id PRIMARY KEY (id)
);
/* Audit table for emp_addr table */
create table emp_addr_audit (
id bigserial,
operation character(1),
addr_id integer,
emp_id integer,
line1 varchar(30),
CONSTRAINT fk_ audit_emp_id FOREIGN KEY emp_audit_id
REFERENCES emp_audit (id) MATCH SIMPLE ON UPDATE CASCADE ON DELETE CASCADE;
);
Next you will need to create a trigger, to store changes. Note, that you will have to monitor changes in both tables and create references to the corresponding stored records.
CREATE TRIGGER t_audit_emp_IUD
AFTER INSERT OR UPDATE OR DELETE -- probably u want only update. Not sure
ON emp
FOR EACH ROW
EXECUTE PROCEDURE emp_modified();
CREATE TRIGGER t_audit_emp_addr_IUD
AFTER INSERT OR UPDATE OR DELETE
ON emp_addr
FOR EACH ROW
EXECUTE PROCEDURE emp_addr_modified();
And finally define the functions. Note, that functions should be stored in database before triggers, since triggers reference to the functions.
Rollback function should take emp_audit.id as an input and restore the state according to the audit table. It would be a good idea to save state before rolling back to prevent possible data loss.
If this doesn't answer your question, please clarify which part do you actually need help with.