<code>
docker run --name dbc -p 54321:5432 -e POSTGRES_PASSWORD=1234 -d postgres
docker exec -it dbc psql -U postgres
\l
CREATE DATABASE hyudb
\c hyudb

CREATE TABLE students
(
    sid    CHAR(20)            NOT NULL, 
    name   CHAR(20)    NOT NULL, 
    login  CHAR(10)    NOT NULL, 
    age    INT            NOT NULL, 
    gpa    REAL          NULL, 
    PRIMARY KEY (sid)
);

ALTER TABLE enrolled ADD PRIMARY KEY (sid, cid)

ALTER TABLE enrolled ADD FOREIGN KEY (sid) REFERENCES students;

#ALTER TABLE enrolled ADD CONSTRAINT cid_grade_unique UNIQUE (cid, grade)

\d+ students
</code>
<code>
nmap -Pnv -p 5432 ec2-54-251-188-3.ap-southeast-1.compute.amazonaws.com

</code>
Get tables
<code>
with pg.connect(connect_string) as conn:
  with conn.cursor() as cur:
    cur.execute("""SELECT table_name FROM information_schema.tables
       WHERE table_schema = 'public'""")
    for table in cur.fetchall():
        print(table)
</code>
<code>
CREATE TABLE public.volunteer
(
    id SERIAL PRIMARY KEY,
    email character varying(100) COLLATE pg_catalog."default",
    password character varying(100) COLLATE pg_catalog."default" NOT NULL,
    name character varying(100) COLLATE pg_catalog."default" NOT NULL,    
    CONSTRAINT volunteer_email_key UNIQUE (email)
)
</code>
sqlalchemy
<code>
flask-sqlacodegen --flask --outfile tc.py "postgres://postgres: - -@c2s2.hanyang.ac.kr:5432/jaunt" --tables "tc_devices,volunteer"
</code>
<code>
$ git remote add upstream https://github.com/[Original Owner Username]/[Original Repository].git
$ git fetch upstream
$ git checkout master
$ git merge upstream/master
$ git push
</code>
<code>
First install the extension

CREATE EXTENSION tsm_system_rows;

Then your query,

SELECT *
FROM table
TABLESAMPLE SYSTEM_ROWS(1000);
</code>