adding base project

app/core/database.py

@@ -0,0 +1,56 @@
+import re
+from urllib.parse import urlparse
+from sqlalchemy import create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import sessionmaker
+from app.core.config import settings
+
+def ensure_database_exists(db_url: str):
+    """
+    If using MySQL, automatically creates the target database if it does not exist
+    (mirrors spring.datasource.url createDatabaseIfNotExist=true).
+    """
+    if db_url.startswith("mysql"):
+        try:
+            import pymysql
+            # Parse connection URL safely
+            clean_url = db_url.replace("mysql+pymysql://", "http://").replace("mysql://", "http://")
+            parsed = urlparse(clean_url)
+            db_name = parsed.path.lstrip("/").split("?")[0]
+            if db_name:
+                conn = pymysql.connect(
+                    host=parsed.hostname,
+                    port=parsed.port or 3306,
+                    user=parsed.username,
+                    password=parsed.password,
+                    connect_timeout=5
+                )
+                with conn.cursor() as cur:
+                    cur.execute(f"CREATE DATABASE IF NOT EXISTS `{db_name}`;")
+                conn.close()
+        except Exception as e:
+            print(f"Note on DB creation: {e}")
+
+ensure_database_exists(settings.DATABASE_URL)
+
+connect_args = {}
+if settings.DATABASE_URL.startswith("sqlite"):
+    connect_args = {"check_same_thread": False}
+
+engine = create_engine(
+    settings.DATABASE_URL,
+    connect_args=connect_args,
+    pool_pre_ping=True
+)
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+Base = declarative_base()
+
+def get_db():
+    """Dependency for obtaining database session per request."""
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()