DEV Community: caglarcercinlidev

HOW TO CREATE A JAR FILE ON A SPRING/MAVEN PROJECT

caglarcercinlidev — Tue, 19 Apr 2022 21:25:59 +0000

A jar file is in fact a server-runnable code.
On terminal execute this command:
mvn package
This command will build the project, run the tests and create a jar file. So be sure that all tests are passing.

After that, check the target folder, jar file will be there.

Now it is time to run this jar file. Command:
java -jar <name>.jar
With this command, the application will be running on the specified localhost port (default 8080). You can test it.

Happy coding with no errors!

HOW TO RUN A SQL FILE AND CREATE A DATABASE

caglarcercinlidev — Thu, 14 Apr 2022 17:04:35 +0000

It is not always a good practice to insert data with a psql command line. Creating a sql file and running it is sometimes easier.

First we create a file with .sql extension (with notepad for example).

DROP TABLE products;

create table products (id serial primary key, name varchar (50) not null, price varchar (50) not null);
 insert into products (name, price) values ('hamburger','10');

Why DROP TABLE?
It would delete the previous table and rewrite it, otherwise it would cause en error.
Then we log into psql.

run \i fastfoodshop.sql

It is important to indicate the correct place of the file.

After that, check table and entries.

Wish you an easy coding!

CREATE A TABLE ON A POSTGRESQL DATABASE

caglarcercinlidev — Thu, 14 Apr 2022 16:51:01 +0000

First some useful commands:

list if databases:
\l

switch to a database:
\c exampledatabase

now it is time to create a table:
CREATE TABLE products (id serial primary key, name varchar (50) not null, price varchar (50) not null);

we have a table but no entries, so:
INSERT INTO products (name, price) VALUES ('hamburger','10');

to check the tables:
\dt

and to see entries on our table:
SELECT * FROM products

wish you an easy coding!

HOW TO CREATE A POSTGRESQL DATABASE ON UBUNTU 20.04

caglarcercinlidev — Thu, 14 Apr 2022 16:34:20 +0000

First open terminal and

sudo apt update
sudo apt install postgresql postgresql-contrib

now you have downloaded necessary libraries. After that:

sudo -i -u postgres

This way you are switched to postgres user. and enter your password (of the previous user)

psql

With psql you are ready to perform postgres commands.

always use

\q

to leave postgres command line.

Finally, to create a database:

CREATE DATABASE exampledatabase;

Wish you an easy coding!