insert into usertable (employeenumber) select empno from usertemp
And this is the error
ERROR: null value in column "id" violates not-null constraint
Just create your table using serial, that will create the sequence and the default value
CREATE TABLE usertable (
id serial,
employeenumber integer
);
Insert should be the same
insert into usertable (employeenumber) select empno from usertemp
Related
I have table Employee in Postgres:
drop table if exists employee;
create table employee (
id uuid default uuid_generate_v4 () primary key,
first_name varchar not null,
last_name varchar not null
);
And another table salary :
drop table if exists salary;
create table salary (
check_id uuid default uuid_generate_v4 () primary key,
salary int not null,
employee_id uuid references employee (id)
);
employee_id is the foreign key to id in the Employee table, but I don't understand how to insert a value inside employee_id since UUID is unique.
I am inserting values into Employee table:
insert into employee (first_name, last_name, email, code) values ( 'jonh', 'smith', 'jonh#example.com', '1');
And then if I try insert values into salary table:
insert into salary (salary ) values ('1000');
Then select command will return employee_id value empty.
But if I make it default uuid_generate_v4 (), then result is: Key (employee_id)=(c4ccd745-02ba-4a0e-8586-32e3c6a2b84a) is not present in table "employee".
I understand that because employee_id is a foreign key it should match with uuid in employee, but since uuid is mostly unique, how can I make it work?
You have to use the uuid that was inserted into the employee table. You can do this with a CTE in a single statement:
WITH new_employee AS (
INSERT INTO employee (first_name, last_name, email, code)
VALUES ('jonh', 'smith', 'jonh#example.com', '1')
RETURNING id
)
INSERT INTO salary (salary, employee_id)
SELECT 1000, id
FROM new_employee;
I have created a table as mentioned below.
create table employee (
surrogate_key bigint IDENTITY(1,1),
first_name varchar(200),
last_name varchar(200),
phone_number varchar(200),
creditcard_number bigint
)
insert into employee values
('gaurang', 'shah', '356-776-4456', '4716973408090483')
However, following code is giving error.
Error
[Code: 500310, SQL State: 0A000] [Amazon](500310) Invalid operation: cannot set an identity column to a value;
insert into employee(first_name,last_name,phone_number,creditcard_number)
values('gaurang', 'shah', '356-776-4456', 4716973408090483)
You have to specify column names when identity column present in the table
One more option is define surrogate key with default like this
surrogate_key bigint generated by default as IDENTITY(1,1),
Then run this query
insert into employee1
values(default,'gaurang', 'shah', '356-776-4456', 4716973408090483)
I have displayed my database schema below.
CREATE TABLE table_group
(
group_id serial NOT NULL,
group_creator_id integer NOT NULL,
group_name character varying(20) NOT NULL,
active_status boolean NOT NULL,
PRIMARY KEY (group_id),
)
CREATE TABLE table_group_members
(
group_member_id serial NOT NULL,
group_id integer REFERENCES table_group (group_id) NOT NULL,
member_user_id integer REFERENCES table_group (group_creator_id) NOT NULL,
PRIMARY KEY (group_member_id)
)
I want to INSERT a new row in the table table_group_members as soon a new row is inserted in table table_group.
I want to pass the group_id and group_creator_id of the newly inserted row in the table table_group as parameters to INSERT query for the table table_group_members
How should I do it using the PostgreSQL TRIGGER?
I am working with Oracle 12c in which I have below table structure:-
CREATE TABLE patients (
patient_id Integer NOT NULL,
customer_id Integer NOT NULL,
title varchar(5) NOT NULL,
fname varchar(125) NOT NULL,
lname varchar(125) NOT NULL,
dob date NOT NULL,
is_medical_card NUMBER(1) NOT NULL CHECK (is_medical_card IN (0,1)),
scheme_number Integer NOT NULL,
status varchar(50) NOT NULL,
created_on date NOT NULL,
last_update_date date NOT NULL,
consent_flag NUMBER(1) NOT NULL CHECK (consent_flag IN (0,1)),
relationship varchar(50) NOT NULL
);
Where patient_id is my primary key so now I want to make it auto increment as well so please let me how can I do this so make it auto increment.
Thanks!
Need to create auto increment to existing column.
You might want to use Identities - Creating a table with an Identity gives you the chance to omit the ID values and let Oracle use a sequence on your desired column:
1. Let's Create the Table:
CREATE TABLE identities (
id NUMBER GENERATED BY DEFAULT ON NULL AS IDENTITY,
description varchar2(100) NOT NULL
);
Table created.
2. You'll want to create a primary key to ensure uniqueness:
alter table identities add constraint id_pk primary key (ID);
Table altered.
3. Let's insert some data in different ways:
INSERT INTO identities (description)
VALUES('Insert Description omitting ID');
1 row created.
INSERT INTO identities (id,description)
VALUES(NULL,'Insert with explicit NULL value');
1 row created.
4. Save the work done
commit;
Commit complete.
5. Check the results
select * from identities;
ID DESCRIPTION
---------- ---------------------------------------------
1 Insert Description omitting ID
2 Insert with explicit NULL value
As you can see we dind't specify any number for the ID, but the Identity on the ID column did for us
Note: Mind that you can manually insert an ID, but this will mess up with the Identity as it'll normally do with a standard Sequence:
INSERT INTO identities (id,description)
VALUES(3,'Manually insert an ID value');
1 row created.
INSERT INTO identities (description)
VALUES('Test Nextval');
INSERT INTO identities (description)
*
ERROR at line 1:
ORA-00001: unique constraint (XXX.ID_PK) violated
This error, because it tries to insert a '3' into the ID that was manually inserted with the statement before.
Check the table:
select * from identities;
ID DESCRIPTION
---------- ---------------------------------------------
1 Insert Description omitting ID
2 Insert with explicit NULL value
3 Manually insert an ID value
Re-Run the "NEXTVAL" insert:
INSERT INTO identities (description)
VALUES('Test Nextval');
1 row created.
Re-Check the table:
select * from identities;
ID DESCRIPTION
---------- ---------------------------------------------
1 Insert Description omitting ID
2 Insert with explicit NULL value
3 Manually insert an ID value
4 Test Nextval
Hope this Helps.
To create table I use:
CREATE TABLE category
(
cat_id serial NOT NULL,
cat_name character varying NOT NULL,
parent_id integer NOT NULL,
CONSTRAINT cat_id PRIMARY KEY (cat_id)
)
WITH (
OIDS=FALSE
);
ALTER TABLE category
OWNER TO pgsql;
parent_id is a id to another category. Now I have a problem: how to cascade delete record with its children? I need to set parent_id as foreign key to cat_id.
I try this:
ALTER TABLE category
ADD CONSTRAINT cat_cat_id_fkey FOREIGN KEY (parent_id)
REFERENCES category (cat_id) MATCH SIMPLE
ON UPDATE CASCADE ON DELETE CASCADE
But it falls with:
ERROR: insert or update on table "category" violates foreign key constraint "cat_cat_id_fkey"
DETAIL: Key (parent_id)=(0) is not present in table "category".
The problem you have - what would be the parent_id of a category at the top of the hierarchy?
If it will be null - it will break the NOT NULL constratint.
If it will be some arbitrary number like 0 - it will break the foreign key (like in your example).
The common solution - drop the NOT NULL constratint on the parent_id and set parent_id to null for top categories.
-- create some fake data for testing
--
DROP SCHEMA tmp CASCADE;
CREATE SCHEMA tmp ;
SET search_path=tmp;
CREATE TABLE category
(
cat_id serial NOT NULL,
cat_name character varying NOT NULL,
parent_id integer NOT NULL,
CONSTRAINT cat_id PRIMARY KEY (cat_id)
);
INSERT INTO category(cat_name,parent_id)
SELECT 'Name_' || gs::text
, gs % 3
FROM generate_series(0,9) gs
;
-- find the records with the non-existing parents
SELECT ca.parent_id , COUNT(*)
FROM category ca
WHERE NOT EXISTS (
SELECT *
FROM category nx
WHERE nx.cat_id = ca.parent_id
)
GROUP BY ca.parent_id
;
-- if all is well: proceed
-- make parent pointer nullable
ALTER TABLE category
ALTER COLUMN parent_id DROP NOT NULL
;
-- set non-existing parent pointers to NULL
UPDATE category ca
SET parent_id = NULL
WHERE NOT EXISTS (
SELECT *
FROM category nx
WHERE nx.cat_id = ca.parent_id
)
;
-- Finally, add the FK constraint
ALTER TABLE category
ADD CONSTRAINT cat_cat_id_fkey FOREIGN KEY (parent_id)
REFERENCES category (cat_id) MATCH SIMPLE
ON UPDATE CASCADE ON DELETE CASCADE
;
This is quite simple.
Here the foreign key parent_id refers to cat_id.
Here a record with parent_id=0 exists but not a record with cat_id=0.