How do you create the table structure in PostgreSQL to make a many-to-many relationship - postgresql

my example so far I would like to know how to create a many to many relationship with these.
CREATE TABLE accounts (
id SERIAL,
first_name VARCHAR(50),
last_name VARCHAR (50),
username VARCHAR (50),
password VARCHAR (500),
account_Type VARCHAR (10),
bday VARCHAR (50),
PRIMARY KEY(id)
);
CREATE TABLE bank_account(
id SERIAL,
account_number INTEGER PRIMARY KEY,
account_balance INTEGER
);


you can create a table like this one:
CREATE TABLE bank_account_accounts(
id serial primary key,
accounts_id integer,
bank_account_id integer
);

Related

When I run this code a syntax error keeps appearing but I am unable to find where it would be

When I run this code, I receive a very vague syntax error: database: syntax error at or near "(". I am unable to find where this syntax error would be.
I have also been told that animal_adoption_history is not an associative entity when it was designed as one.
What have I done wrong when writing it?
The code:
DROP TABLE IF EXISTS customer;
DROP TABLE IF EXISTS animal;
DROP TABLE IF EXISTS animal_adoption_history;
create table customer (
customer_id CHAR(9) NOT NULL,
c_first_name VARCHAR(25),
c_last_name VARCHAR(50),
c_gender CHAR(1),
c_phone_number VARCHAR(20),
c_email_address VARCHAR(45),
c_date_of_birth DATE,
c_address_number VARCHAR(10),
c_street_name VARCHAR(30),
c_city VARCHAR(50),
c_state CHAR(3),
c_postcode CHAR(4),
c_has_adopted_before CHAR(1),
constraint customer_PK PRIMARY KEY (customer_id)
);
create table animal (
animal_id CHAR(9) NOT NULL,
a_animal_type VARCHAR(20) ,
a_breed VARCHAR(50),
a_colour VARCHAR(30),
a_size VARCHAR(20),
a_weight_kg VARCHAR(10),
a_description VARCHAR(75),
a_name VARCHAR(30),
a_date_of_birth DATE,
a_sex CHAR(1),
a_animal_cost INT(10),
a_microchip_status CHAR(1),
a_vaccination_status CHAR(1),
constraint animal_PK PRIMARY KEY (animal_id)
);
create table animal_adoption_history (
health_conditions VARCHAR(100),
is_available_to_adopt CHAR(1),
has_been_adopted_previously CHAR(1),
reason_for_entry VARCHAR(75),
date_entered DATE,
animal_id CHAR(9) NOT NULL,
customer_id CHAR(9) NOT NULL,
constraint animal_adoption_history_PK PRIMARY KEY (animal_id, customer_id),
constraint animal_adoption_history_FK1 FOREIGN KEY (animal) references animal(animal_id)
constraint animal_adoption_history_FK2 FOREIGN KEY (customer_id) references customer(customer_id)
);
INSERT INTO customer (customer_id,c_first_name,c_last_name,c_gender,c_phone_number,c_email_address,c_date_of_birth,c_address_number,c_street_name,c_city,c_state,c_postcode,c_has_adopted_before)
VALUES ('C00000001','Olivia','Smith','F','0422425392','olivia.smith#gmail.com','1980-06-22','2','Henderson Street','Bondi','NSW','2092','Yes');
INSERT INTO customer (customer_id,c_first_name,c_last_name,c_gender,c_phone_number,c_email_address,c_date_of_birth,c_address_number,c_street_name,c_city,c_state,c_postcode,c_has_adopted_before)
VALUES ('C00000002','Taylor','Brown','F','0422435394','taylor.brown#gmail.com','1999-02-24','62','Ultimo Avenue','Bondi','NSW','2092','No');
INSERT INTO customer (customer_id,c_first_name,c_last_name,c_gender,c_phone_number,c_email_address,c_date_of_birth,c_address_number,c_street_name,c_city,c_state,c_postcode,c_has_adopted_before)
VALUES ('C00000003','Sarah','Li','F','0422425342','sarah.li#gmail.com','1997-02-22','27','Winchester Street','Epping','NSW','2092','Yes');
INSERT INTO customer (customer_id,c_first_name,c_last_name,c_gender,c_phone_number,c_email_address,c_date_of_birth,c_address_number,c_street_name,c_city,c_state,c_postcode,c_has_adopted_before)
VALUES ('C00000004','Charlie','Swift','M','0432425392','charlie.swift#gmail.com','1998-02-22','22','Henderson Lane','Lindfield','NSW','2092','No');
INSERT INTO customer (customer_id,c_first_name,c_last_name,c_gender,c_phone_number,c_email_address,c_date_of_birth,c_address_number,c_street_name,c_city,c_state,c_postcode,c_has_adopted_before)
VALUES ('C00000005','Heath','Davidson','M','0422425911','heath.davidson#gmail.com','2003-01-22','22','Station Street','Manly','NSW','2092','Yes');
INSERT INTO animal (animal_id,a_animal_type,a_breed,a_colour,a_size,a_weight_kg,a_description,a_name,a_date_of_birth,a_sex,a_animal_cost,a_microchip_status,a_vaccination_status)
VALUES ('A00000001','Dog','Pug','Light brown','Small','5','Playful yet enjoys cuddles','Mia','2020-02-22','F','3100','Y','Y');
INSERT INTO animal (animal_id,a_animal_type,a_breed,a_colour,a_size,a_weight_kg,a_description,a_name,a_date_of_birth,a_sex,a_animal_cost,a_microchip_status,a_vaccination_status)
VALUES ('A00000002','Cat','Tabby','Orange','Small','4','Quiet and loves the sun','Garfield','2010-04-28','M','1400','Y','N');
INSERT INTO animal (animal_id,a_animal_type,a_breed,a_colour,a_size,a_weight_kg,a_description,a_name,a_date_of_birth,a_sex,a_animal_cost,a_microchip_status,a_vaccination_status)
VALUES ('A00000003','Bird','Budgie','Green and yellow','Extra Small','0.035','Very loud when hungry','Roody','11-14','F','1200','N','Y');
INSERT INTO animal (animal_id,a_animal_type,a_breed,a_colour,a_size,a_weight_kg,a_description,a_name,a_date_of_birth,a_sex,a_animal_cost,a_microchip_status,a_vaccination_status)
VALUES ('A00000004','Rabbit','Holland Lop','Light brown and white','Small','5','Fluffy and enjoys lettuce snacks','Thumper','2018-19-04','F','900','N','N');
INSERT INTO animal (animal_id,a_animal_type,a_breed,a_colour,a_size,a_weight_kg,a_description,a_name,a_date_of_birth,a_sex,a_animal_cost,a_microchip_status,a_vaccination_status)
VALUES ('A00000005','Dog','Golden Retriever','Dark blonde','Large','32','Loves going for long walks','Milo','2014-05-30','M','2500','Y','Y');
INSERT INTO animal_adoption_history (health_conditions,is_available_to_adopt,has_been_adopted_previously,reason_for_entry,date_entered,animal_id,customer_id)
VALUES ('None','Y','Y','Owner moved away','2021-08-18','A00000001','C00000001');
INSERT INTO animal_adoption_history (health_conditions,is_available_to_adopt,has_been_adopted_previously,reason_for_entry,date_entered,animal_id,customer_id)
VALUES ('None','N','N','Newborn looking for home','2022-07-13','A00000003','C00000005');
INSERT INTO animal_adoption_history (health_conditions,is_available_to_adopt,has_been_adopted_previously,reason_for_entry,date_entered,animal_id,customer_id)
VALUES ('Diabetes','Y','Y','Owner passed away','2019-11-01','A00000004','C00000001');
INSERT INTO animal_adoption_history (health_conditions,is_available_to_adopt,has_been_adopted_previously,reason_for_entry,date_entered,animal_id,customer_id)
VALUES ('None','Y','N','Previous household abuse','2014-09-19','A00000002','C00000004');
INSERT INTO animal_adoption_history (health_conditions,is_available_to_adopt,has_been_adopted_previously,reason_for_entry,date_entered,animal_id,customer_id)
VALUES ('Arthritis','Y','Y','Newborn looking for home','2016-04-26','A00000005','C00000002');
Thanks!

INT(10) is not valid datatype:
a_animal_cost INT(10)
There are other issues as well, you have to fix this.

You have a number of errors in your code. When running PostgreSQL only lists the first one, which in this case is the line a_animal_cost INT(10),. Integers are a fixed size so it is wrong to attempt to specify a size for it.
Also do not use char(1) for Yes ('Y') No ('N') fields. PostgreSQL has a native boolean data type for this purpose, so use it.
When deleting tables, you need to delete the lowest tables in the hierarchy first (foreign key etc).
Finally, you can chain multiple inserts as values together.
Putting all this together, I would recommend that you use something like this:
DROP TABLE IF EXISTS animal_adoption_history;
DROP TABLE IF EXISTS animal;
DROP TABLE IF EXISTS customer;
create table customer (
customer_id CHAR(9) NOT NULL,
c_first_name VARCHAR(25),
c_last_name VARCHAR(50),
c_gender CHAR(1),
c_phone_number VARCHAR(20),
c_email_address VARCHAR(45),
c_date_of_birth DATE,
c_address_number VARCHAR(10),
c_street_name VARCHAR(30),
c_city VARCHAR(50),
c_state CHAR(3),
c_postcode CHAR(4),
c_has_adopted_before boolean,
constraint customer_PK PRIMARY KEY (customer_id)
);
create table animal (
animal_id CHAR(9) NOT NULL,
a_animal_type VARCHAR(20) ,
a_breed VARCHAR(50),
a_colour VARCHAR(30),
a_size VARCHAR(20),
a_weight_kg VARCHAR(10),
a_description VARCHAR(75),
a_name VARCHAR(30),
a_date_of_birth DATE,
a_sex CHAR(1),
a_animal_cost INT,
a_microchip_status boolean,
a_vaccination_status boolean,
constraint animal_PK PRIMARY KEY (animal_id)
);
create table animal_adoption_history (
health_conditions VARCHAR(100),
is_available_to_adopt boolean,
has_been_adopted_previously boolean,
reason_for_entry VARCHAR(75),
date_entered DATE,
animal_id CHAR(9) NOT NULL,
customer_id CHAR(9) NOT NULL,
constraint animal_adoption_history_PK PRIMARY KEY (animal_id, customer_id),
constraint animal_adoption_history_FK1 FOREIGN KEY (animal_id) references animal(animal_id),
constraint animal_adoption_history_FK2 FOREIGN KEY (customer_id) references customer(customer_id)
);
INSERT INTO customer (customer_id,c_first_name,c_last_name,c_gender,c_phone_number,c_email_address,c_date_of_birth,c_address_number,
c_street_name,c_city,c_state,c_postcode,c_has_adopted_before) VALUES
('C00000001','Olivia','Smith','F','0422425392','olivia.smith#gmail.com','1980-06-22','2',
'Henderson Street','Bondi','NSW','2092',true),
('C00000002','Taylor','Brown','F','0422435394','taylor.brown#gmail.com','1999-02-24','62',
'Ultimo Avenue','Bondi','NSW','2092',false),
('C00000003','Sarah','Li','F','0422425342','sarah.li#gmail.com','1997-02-22','27',
'Winchester Street','Epping','NSW','2092',true),
('C00000004','Charlie','Swift','M','0432425392','charlie.swift#gmail.com','1998-02-22','22',
'Henderson Lane','Lindfield','NSW','2092',false),
('C00000005','Heath','Davidson','M','0422425911','heath.davidson#gmail.com','2003-01-22','22',
'Station Street','Manly','NSW','2092',true);
INSERT INTO animal (animal_id,a_animal_type,a_breed,a_colour,a_size,a_weight_kg,a_description,a_name,a_date_of_birth,
a_sex,a_animal_cost,a_microchip_status,a_vaccination_status) VALUES
('A00000001','Dog','Pug','Light brown','Small','5','Playful yet enjoys cuddles','Mia','2020-02-22',
'F','3100',true,true),
('A00000002','Cat','Tabby','Orange','Small','4','Quiet and loves the sun','Garfield','2010-04-28',
'M','1400',true,false),
('A00000003','Bird','Budgie','Green and yellow','Extra Small','0.035','Very loud when hungry','Roody','2020-11-14',
'F','1200',false,true),
('A00000004','Rabbit','Holland Lop','Light brown and white','Small','5','Fluffy and enjoys lettuce snacks','Thumper','2018-04-19',
'F','900',false,false),
('A00000005','Dog','Golden Retriever','Dark blonde','Large','32','Loves going for long walks','Milo','2014-05-30',
'M','2500',true,true);
INSERT INTO animal_adoption_history (health_conditions,is_available_to_adopt,has_been_adopted_previously,reason_for_entry,
date_entered,animal_id,customer_id) VALUES
('None',true,true,'Owner moved away','2021-08-18','A00000001','C00000001'),
('None',false,false,'Newborn looking for home','2022-07-13','A00000003','C00000005'),
('Diabetes',true,true,'Owner passed away','2019-11-01','A00000004','C00000001'),
('None',true,false,'Previous household abuse','2014-09-19','A00000002','C00000004'),
('Arthritis',true,true,'Newborn looking for home','2016-04-26','A00000005','C00000002');

Hello I'm pretty new to PostgreSQL so I trying to create a one to one relationship between the tables account and bank_account

I tried using a foreign key, but it still shows them as being separate and not connected is there something I'm missing here, my goal was to originally link the persons name to the account_balance.
CREATE TABLE accounts (
id SERIAL,
first_name VARCHAR(50),
last_name VARCHAR (50),
username VARCHAR (50),
password VARCHAR (500),
account_Type VARCHAR (10),
bday VARCHAR (50),
PRIMARY KEY(id)
);
CREATE TABLE bank_account(
id SERIAL,
account_number INTEGER PRIMARY KEY,
account_balance INTEGER,
CONSTRAINT bank_users
FOREIGN KEY (id)
REFERENCES accounts(id)
ON DELETE CASCADE
);
INSERT INTO accounts (
first_name,
last_name,
username,
password,
account_Type,
bday)
VALUES ('bob', 'john', 'bob#gmail.com', crypt('bob1',gen_salt('bf')),'Manager', '01/01/1985'),
('Tom', 'lin', 'tom#gmail.com', 'tom1', 'Manager', '5/23/1990');
INSERT INTO bank_account(
account_number,
account_balance)
VALUES ('1234', '50000'),('4332', '100000');

Does postgresql require unique constraint names when defining FOREIGN KEYS

Here is my schema for database tables:
CREATE TABLE users (
user_id INTEGER NOT NULL,
device_id INTEGER,
user_points INTEGER,
cookie VARCHAR,
PRIMARY KEY (user_id)
);
CREATE TABLE admins (
admin_id INTEGER NOT NULL,
username VARCHAR,
password VARCHAR
);
CREATE TABLE admin_adventure (
adventure_id INTEGER NOT NULL,
admin_id INTEGER,
PRIMARY KEY (adventure_id)
);
CREATE TABLE adventures (
adventure_id INTEGER NOT NULL,
prize_id INTEGER,
novella_id INTEGER,
PRIMARY KEY (adventure_id)
);
Here I'm trying to define FOREIGN KEYS:
ALTER TABLE admin_adventure ADD FOREIGN KEY ( admin_id ) REFERENCES admins ( admin_id );
ALTER TABLE admin_adventure ADD FOREIGN KEY ( adventure_id ) REFERENCES adventures ( adventure_id );
And here is the error I get when trying to migrate with Flyway:
ERROR: there is no unique constraint matching given keys for
referenced table "admins"
Can someone explain what I'm doing wrong and why I get this error?

The error message is complaining that you are trying to link a foreign key to a column in another table which is not unique (e.g. a primary key). Try making the admin_id column in the admins table a primary key:
CREATE TABLE admins (
admin_id INTEGER NOT NULL,
username VARCHAR,
password VARCHAR,
PRIMARY KEY (admin_id)
);

Like the documentation says:
A foreign key must reference columns that either are a primary key or form a unique constraint.
So you must either
ALTER TABLE admins ADD PRIMARY KEY (admin_id);
or
ALTER TABLE admins ADD UNIQUE (admin_id);

relation tables inheritance modeling

I want to understand inheritance in postgresql, simple whitch columns in whitch tables.
CREATE TABLE users (
id serial PRIMARY KEY,
username VARCHAR UNIQUE NOT NULL,
email VARCHAR NOT NULL,
password_salt VARCHAR,
password_hash VARCHAR,
avatar serial
)
CREATE TABLE groups (
id serial PRIMARY KEY NOT NULL,
name VARCHAR,
email VARCHAR,
avatar serial,
)
CREATE TABLE accounts (
id serial PRIMARY KEY NOT NULL,
name VARCHAR,
avatar serial,
rating json NOT NULL,
);
CREATE TABLE users_to_accounts (
id serial PRIMARY KEY NOT NULL,
start_time DATETIME NOT NULL,
end_time DATETIME,
)
CREATE TABLE account_subscryptions (
user_id serial NOT NULL,
account_id serial NOT NULL,
) INHERITS users_to_accounts
CREATE TABLE account_memberships (
user_id serial NOT NULL,
account_id serial NOT NULL,
) INHERITS users_to_accounts
CREATE TABLE users_to_groups (
id serial PRIMARY KEY NOT NULL,
start_time DATETIME NOT NULL,
end_time DATETIME,
)
CREATE TABLE group_subscryptions (
user_id serial NOT NULL,
group_id serial NOT NULL,
) INHERITS users_to_groups
CREATE TABLE group_memberships (
user_id serial NOT NULL,
group_id serial NOT NULL,
) INHERITS users_to_groups
Now.
1. Is it good design to have foreign keys in child tables an all common data in "abstract" table?
2. Is there any traps in future changes of database with inherited relantion tables?
3. I am all wrong and there is a better way for this schema?
4. I want to create good database schema and generate graphql api in postgraphile, looking in google for half day, did not gave me any one good or best solution, so every link will by great.
It may be usefull for others, I think. Thanks

Postgresql Creating a Schema with tables in it

Here's my script.
CREATE SCHEMA testSchema
create table REF_PRODUCT (
id int8 not null,
created_date timestamp,
CODE varchar(255),
DESCRIPTION varchar(255),
LOCATION varchar(255),
MANUFACTURER varchar(255),
NAME varchar(255),
COST numeric(19, 2),
DEALERS_PRICE numeric(19, 2),
SUGGESTED_RETAIL_PRICE numeric(19, 2),
STOCK int4,
PRODUCT_TYPE varchar(255),
picture_id int8,
primary key (id)
)
create table TXN_LINE_ITEM (
id int8 not null,
created_date timestamp,
cancelled boolean,
cost numeric(19, 2),
dp numeric(19, 2),
itemCode varchar(255),
itemName varchar(255),
priceType varchar(255),
qty int4,
refunded boolean,
srp numeric(19, 2),
total numeric(19, 2),
transactionRecord_id int8,
primary key (id)
)
create table TXN_PRODUCT_PICTURE (
id int8 not null,
created_date timestamp,
picture bytea,
primary key (id)
)
create table TXN_TRANSACTION_RECORD (
id int8 not null,
created_date timestamp,
total numeric(19, 2),
transaction_date timestamp,
TRANSACTION_NUMBER varchar(255),
VALID boolean,
primary key (id)
)
alter table REF_PRODUCT
add constraint FK_sjugahpelk16qj5h3w8dli42l
foreign key (picture_id)
references TXN_PRODUCT_PICTURE;
alter table TXN_LINE_ITEM
add constraint FK_o5mslaahpil9d3g9rl2s22rpm
foreign key (transactionRecord_id)
references TXN_TRANSACTION_RECORD;
create table SEQ_ENTITY_ID (
sequence_name varchar(255),
sequence_next_hi_value int4
);
The problem is the fk relationships specified in alter table statement is not being created
Because of this error.
[WARNING ] CREATE SCHEMA testSchema
create table REF_PRODUCT (
id int8 not null,
created_date timestamp,
CODE varchar(255),
DESCRIPTION varchar(255),
LOCATION varchar(255),
MANUFACTURER varchar(255),
NAME varchar(255),
COST numeric(19, 2),
DEALERS_PRICE numeric(19, 2),
SUGGESTED_RETAIL_PRICE numeric(19, 2),
STOCK int4,
PRODUCT_TYPE varchar(255),
picture_id int8,
primary key (id)
)
create table TXN_LINE_ITEM (
id int8 not null,
created_date timestamp,
cancelled boolean,
cost numeric(19, 2),
dp numeric(19, 2),
itemCode varchar(255),
itemName varchar(255),
priceType varchar(255),
qty int4,
refunded boolean,
srp numeric(19, 2),
total numeric(19, 2),
transactionRecord_id int8,
primary key (id)
)
create table TXN_PRODUCT_PICTURE (
id int8 not null,
created_date timestamp,
picture bytea,
primary key (id)
)
create table TXN_TRANSACTION_RECORD (
id int8 not null,
created_date timestamp,
total numeric(19, 2),
transaction_date timestamp,
TRANSACTION_NUMBER varchar(255),
VALID boolean,
primary key (id)
)
alter table REF_PRODUCT
add constraint FK_sjugahpelk16qj5h3w8dli42l
foreign key (picture_id)
references TXN_PRODUCT_PICTURE
ERROR: syntax error at or near "alter"
LINE 53: alter table REF_PRODUCT
^
[WARNING ] alter table TXN_LINE_ITEM
add constraint FK_o5mslaahpil9d3g9rl2s22rpm
foreign key (transactionRecord_id)
references TXN_TRANSACTION_RECORD
ERROR: relation "txn_line_item" does not exist
[WARNING ] create table SEQ_ENTITY_ID (
sequence_name varchar(255),
sequence_next_hi_value int4
)
ERROR: relation "seq_entity_id" already exists
NOTE THAT: There's no existing tables on the said Schema I have made. What have I missed?

I think you have two ways of doing this.
The first one: don't run one create schema statement, but run individual statements for each part (this is what I prefer). You can still do that as a single transaction:
begin transaction;
CREATE SCHEMA testSchema; -- only create the namespace
-- make the new schema the default schema
-- so the the tables do not need to be full qualified
set search_path = testschema;
create table REF_PRODUCT (
...
);
create table TXN_LINE_ITEM (
...
);
create table TXN_PRODUCT_PICTURE (
...
);
create table TXN_TRANSACTION_RECORD (
...
);
alter table REF_PRODUCT
add constraint fk_product_picture
foreign key (picture_id)
references TXN_PRODUCT_PICTURE;
alter table TXN_LINE_ITEM
add constraint FK_line_item_trans_record
foreign key (transactionRecord_id)
references TXN_TRANSACTION_RECORD;
create table SEQ_ENTITY_ID (
sequence_name varchar(255),
sequence_next_hi_value int4
);
commit;
The other option is to move the foreign keys into the table definition, but then you need to re-order your create table statements:
CREATE SCHEMA testSchema
create table TXN_PRODUCT_PICTURE (
...
)
create table TXN_TRANSACTION_RECORD (
...
)
create table REF_PRODUCT (
...,
constraint fk_product_picture
foreign key (picture_id)
references TXN_PRODUCT_PICTURE
)
create table TXN_LINE_ITEM (
...
constraint FK_line_item_trans_record
foreign key (transactionRecord_id)
references TXN_TRANSACTION_RECORD
)
create table SEQ_ENTITY_ID (
sequence_name varchar(255),
sequence_next_hi_value int4
)
;
Unrelated, but:
What is this SEQ_ENTITY_ID table for? Why don't you use native Postgres sequences. They will be much faster, more scalable and more robust than anything you can do in your application to generate unique numbers