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DATABASE ERROR FIX - COMPLETE GUIDE

Problem Summary

When you tried to start the Spring Boot application, you got this error:

org.hibernate.exception.SQLGrammarException: 
Unable to obtain isolated JDBC connection 
[Unknown database 'spl_auction_db']

Root Cause: The MySQL database spl_auction_db doesn't exist yet.

Why This Happened

  1. Application tries to connect to MySQL database at startup
  2. Hibernate configuration is set to ddl-auto=update (which updates existing schema)
  3. But database must exist first for Hibernate to connect
  4. Database was never created manually

How to Fix It

Prerequisites

  • MySQL Server 8.0+ installed
  • MySQL is running
  • You have access to MySQL with credentials: root / soumya@0210

Step-by-Step Fix

Method 1: MySQL Workbench (Easiest - Recommended)

  1. Open MySQL Workbench

    • Start → Search → MySQL Workbench → Open

  2. Create New Query

    • File → New Query Tab
    • Or click the "+" icon next to query tabs

  3. Paste SQL Command

    CREATE DATABASE IF NOT EXISTS spl_auction_db;

  4. Execute

    • Click lightning bolt icon (Execute)
    • Or press Ctrl+Enter

  5. Verify Success

    • You should see message: "Query executed successfully"
    • In left panel, refresh (right-click Schemas → Refresh)
    • spl_auction_db should appear

Method 2: Command Line

Windows PowerShell:

# Navigate to your project
cd "C:\Users\soumyadeep DEY\IdeaProjects\SPL-2"

# Create database
mysql -u root -psoumya@0210 -e "CREATE DATABASE spl_auction_db;"

# Verify
mysql -u root -psoumya@0210 -e "SHOW DATABASES LIKE 'spl_auction_db';"

Windows Command Prompt:

mysql -u root -psoumya@0210 -e "CREATE DATABASE spl_auction_db;"

If mysql command not found, use full path:

"C:\Program Files\MySQL\MySQL Server 8.0\bin\mysql" -u root -psoumya@0210 -e "CREATE DATABASE spl_auction_db;"

After Creating Database

Rebuild and Run Application

cd "C:\Users\soumyadeep DEY\IdeaProjects\SPL-2"

# Clean build
.\mvnw clean compile

# Run application
.\mvnw spring-boot:run

Expected Output

[INFO] BUILD SUCCESS
...
2026-01-01T... INFO 12345 --- [  restartedMain] o.s.b.w.e.tomcat.TomcatWebServer: Tomcat started on port(s): 8080
2026-01-01T... INFO 12345 --- [  restartedMain] com.example.spl2.Spl2Application: Started Spl2Application in X.XXX seconds

Access Application

http://localhost:8080/index.html

What Happens Next

  1. Hibernate Auto-DDL: Spring Boot automatically creates tables:

    • players - Player data
    • teams - Team data
    • bids - Bid history
    • auction_state - Auction progress

  2. No Manual SQL Needed: All tables created automatically

  3. Database Ready: You can immediately start using the application

Database Configuration

File: src/main/resources/application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/spl_auction_db?useSSL=false&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=soumya@0210
spring.jpa.hibernate.ddl-auto=update

What each line means:

  • url: Connect to MySQL on localhost, port 3306, database spl_auction_db
  • username: Login as user root
  • password: Password is soumya@0210
  • ddl-auto=update: Automatically create/update tables if needed

Verify Database Created

In MySQL Workbench

  1. Open MySQL Workbench
  2. Look at left panel under "SCHEMAS"
  3. Find spl_auction_db
  4. Click arrow to expand
  5. Should see tables after running application:
    • players
    • teams
    • bids
    • auction_state

In Command Line

mysql -u root -psoumya@0210 spl_auction_db -e "SHOW TABLES;"

Should output:

+------------------------+
| Tables_in_spl_auction_db|
+------------------------+
| auction_state          |
| bids                   |
| players                |
| teams                  |
+------------------------+

Common Issues & Solutions

Issue 1: "Unknown database 'spl_auction_db'"

Solution: Follow the "How to Fix It" section above

Issue 2: "Access denied for user 'root'"

Solution:

  • Check password is exactly: soumya@0210
  • Make sure no typos
  • Verify MySQL user 'root' exists

Issue 3: "MySQL server has gone away"

Solution:

  • MySQL is not running
  • Windows: Start → Services → MySQL80 → Start
  • Or in Command Prompt (as Admin): net start MySQL80

Issue 4: "mysql command not found"

Solution:

  • MySQL bin directory not in PATH
  • Use full path: C:\Program Files\MySQL\MySQL Server 8.0\bin\mysql
  • Or add to system PATH

Issue 5: Database created but still getting error

Solution:

  • Restart the Spring Boot application
  • Clear any cached connections
  • Check connection properties in application.properties

Testing the Setup

After starting the application, test these:

  1. Homepage loads: http://localhost:8080/index.html
  2. Add a team: Click "Add Team" button
  3. Register a player: Click "Register Player" button
  4. Start auction: Click "Auction" button
  5. Tables created: Check database (see "Verify" section above)

Configuration Details

MySQL Requirements

  • Version: 8.0+
  • Charset: utf8mb4 (default)
  • Collation: utf8mb4_unicode_ci (default)
  • Engine: InnoDB (default)

Spring Boot Configuration

  • DDL Mode: update (auto-create/update tables)
  • Show SQL: false (don't log all SQL)
  • Format SQL: true (pretty print SQL in logs)

Files Created

  • DATABASE_SETUP.md - Comprehensive database setup guide
  • QUICK_DATABASE_FIX.txt - Quick reference card
  • This file - Complete problem and solution

Next Actions

  1. ✅ Create database (follow "How to Fix It" above)
  2. ✅ Restart application
  3. ✅ Access http://localhost:8080/index.html
  4. ✅ Start using the system!

Support

If you still have issues:

  1. Check MySQL is running

    • Windows: Services → MySQL80 should say "Running"
    • Test: mysql -u root -psoumya@0210 -e "SELECT 1;"

  2. Verify credentials

    • Check application.properties for correct username/password
    • Test: mysql -u root -psoumya@0210 -e "SHOW DATABASES;"

  3. Check database exists

    • Command: mysql -u root -psoumya@0210 -e "SHOW DATABASES LIKE 'spl_auction_db';"

  4. Check port 3306 is open

    • Firewall might be blocking
    • Windows Defender → Allow MySQL through firewall

Status: ✅ Complete Fix Available

Time to Fix: ~5 minutes

Difficulty: Easy - Just create one database

After Fix: Application will be fully functional!