Update README with Oracle XE 21c setup details

Added detailed instructions and configuration for Oracle XE 21c with Docker Compose.

README.md

@@ -1 +1,173 @@
-# docker-oracle
+# 🐳 Oracle XE 21c with Docker Compose
+
+This project provides a clean and production-ready setup for running **Oracle Database Express Edition (XE) 21c** using **Docker Compose**.
+
+It is designed to be:
+
+* Easy to run 🚀
+* Safe for development & testing 🧪
+* Clean and maintainable 🧼
+
+---
+
+## 📦 Requirements
+
+Make sure you have the following installed:
+
+* **Docker** 20+
+* **Docker Compose** v2+
+
+Check versions:
+
+```bash
+docker --version
+docker-compose version
+```
+
+---
+
+## 📁 Project Structure
+
+```
+.
+├── docker-compose.yml
+└── README.md
+```
+
+---
+
+## ⚙️ Docker Compose Configuration
+
+```yaml
+services:
+  oracle-xe:
+    image: gvenzl/oracle-xe:21-slim
+    container_name: oracle-xe
+    hostname: oracle-xe
+    restart: always
+
+    ports:
+      - "1521:1521"   # Oracle Listener
+
+    environment:
+      ORACLE_PASSWORD: "ChangeMeStrong!"   # SYS / SYSTEM password
+      ORACLE_DATABASE: "XEPDB1"            # Default Pluggable DB
+      ORACLE_CHARACTERSET: "AL32UTF8"      # Unicode charset
+
+    volumes:
+      - oracle-data:/opt/oracle/oradata
+
+volumes:
+  oracle-data:
+    name: oracle-xe-data
+```
+
+---
+
+## 🚀 Getting Started
+
+### 1️⃣ Start the container
+
+```bash
+docker-compose up -d
+```
+
+### 2️⃣ Check container status
+
+```bash
+docker ps
+```
+
+You should see:
+
+```
+oracle-xe   Up ...   0.0.0.0:1521->1521/tcp
+```
+
+---
+
+## 🔌 Database Connection Info
+
+Use the following details to connect:
+
+| Setting      | Value             |
+| ------------ | ----------------- |
+| Host         | `localhost`       |
+| Port         | `1521`            |
+| Service Name | `XEPDB1`          |
+| Username     | `SYS`             |
+| Password     | `ChangeMeStrong!` |
+
+---
+
+## 💻 Example Connection (SQL*Plus)
+
+```bash
+sqlplus sys/ChangeMeStrong!@localhost/XEPDB1
+```
+
+---
+
+## 🗄️ Persistent Storage
+
+Database files are stored in a **named Docker volume**:
+
+```
+oracle-xe-data
+```
+
+This ensures your data survives container restarts and upgrades.
+
+To inspect:
+
+```bash
+docker volume inspect oracle-xe-data
+```
+
+---
+
+## 🔐 Security Notes
+
+⚠️ **Important:**
+Change the default password before using this setup in any shared or production environment.
+
+Recommended:
+
+```yaml
+ORACLE_PASSWORD: "Use-A-Strong-And-Unique-Password"
+```
+
+---
+
+## 🛠️ Useful Commands
+
+### Stop containers
+
+```bash
+docker compose down
+```
+
+### Stop and remove everything (⚠️ data will remain)
+
+```bash
+docker-compose down --remove-orphans
+```
+
+### Remove volume too (⚠️ ALL DATA WILL BE LOST)
+
+```bash
+docker volume rm oracle-xe-data
+```
+
+---
+
+## 📜 License
+
+This setup uses the community image maintained by **gvenzl**.
+Please review Oracle XE license terms before using in production.
+
+---
+
+## Issues, Feature Requests or Support
+
+Please use the Issue > New Issue button to submit issues, feature requests or support issues directly to me. You can also send an e-mail to akin.bicer@outlook.com.tr.