Foreword

Perhaps Using H2 DB isn't hard for someone who has used it before. However, setting up and initializing projects can often be time-consuming and fraught with unexpected errors.

It holds me for a long time with errors occurring, and unexpected issues can be very discouraging. Frankly, I can say I hate to do this first-hand job......But, If I document my process, it can surely be beneficial. (Sometimes, I am exhauted even before starting a project, It made me think to myself that I am a fool....) This has always been time-comsuming task, while it's also very worthwhile. I hope I can get used to these processes, even if i have to handle new tasks.

H2 DB Installation (prerequisite : Java)

For Java 17 and Spring 3, We should use H2 after 2.1.214v

https://www.h2database.com/html/main.html

By default, H2 db will be installed in C:\Program Files (x86)\H2

3. Verify H2 Database Installation

Run the H2 Console

Success Image -> localhost:8082

4.Create database file(connecting H2)

Check where your working directory is located.

jdbc:h2:D:\Spring Initializr\querydsl (refer to the images below)

I tried to connect H2 with the file path : jdbc:h2:D:\Spring Initializr\querydsl

but,,, see below.

it says Database "D:/ ~~ /querydsl" not found.

Why.....??????????????????????? Ah... perhaps, I didn't set DB configuration.

Driver org.h2.Driver is not suitable for ~~~ ==> JDBC URL issue

( detailed : The error message "Driver org.h2.Driver is not suitable for D:\Spring Initializr\querydsl 08001/0" indicates that there might be an issue with the JDBC URL or the driver setup in your database management tool. )

`application.yml`:

yamlCopy codespring:
  datasource:
    url: jdbc:h2:file:D:/Spring Initializr/querydsl/querydsl_db
    driver-class-name: org.h2.Driver
    username: sa
    password: 
  jpa:
    database-platform: org.hibernate.dialect.H2Dialect
  h2:
    console:
      enabled: true
      path: /h2-console

JDBC URL should be -> jdbc:h2:file:D:/Spring Initializr/querydsl/querydsl_db

Ensure that the jdbc:h2:file URL points to a directory where you want the database file to be created.

Success!

5.Verify database file generation

~.mv.db files should be generated in the working directory where I used for JDBC URL Connection.

We need to check if ~.mv.db file is successfully generated.

Now you can see both querydsl.mv.db and querydsl_db.mv.db, which means that database files have been successfully generated by connecting to the H2 database.

you can check this in the Spring Project.

+Errors While Accessing H2 database

1.While running H2 Console, If you encounter 'javaw' error:

Refer to this URL

: https://hashnode.com/edit/clyh4af39000t09kwfcw33qnp

-> It's related to Java Installation, I've never imagined that I didn't install Java while I join a team project.

Error Snapshot

2.8082 port already be in use

: I run H2 Console Command Line : It says, Port may be in use (8082 port)

Open cmd> netstat -ano | findstr "8082"
```
 netstat -ano | findstr "8082"
```

This output indicates that 8082 port's PID is 5696 (Process Identifier)

Ctrl + Alt + Del => Task Manager

Task Manager -> Details Tap -> End task (terminate)

: Nothing on H2 Console command line

Run H2 Console again

: Works Well.............!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Like I mentioned above, I was about to make a document for my future use and practice this. This Error is lively happened twice........... When i solved this problem, Frankly speaking, I thought It's a coincidence, but this error happened again. I just tried to do trouble-shooting with the way that I used, Surprisingly, I could resolve this.(Just in case, I just tried this step by step while I took a snapshot, but it works well..!)

Surely, Making document can organize my thoughts well and helped me to practice with high focus.....! (I am so glad I took a picutre)