src/db.py

@@ -28,12 +28,13 @@ def init_db(db_path: str) -> sqlite3.Connection:
             pnl REAL DEFAULT 0.0,
             market TEXT DEFAULT 'KR',
             exchange_code TEXT DEFAULT 'KRX',
-            decision_id TEXT
+            decision_id TEXT,
+            mode TEXT DEFAULT 'paper'
         )
         """
     )
 
-    # Migration: Add market and exchange_code columns if they don't exist
+    # Migration: Add columns if they don't exist (backward-compatible schema upgrades)
     cursor = conn.execute("PRAGMA table_info(trades)")
     columns = {row[1] for row in cursor.fetchall()}
 
@@ -45,6 +46,8 @@ def init_db(db_path: str) -> sqlite3.Connection:
         conn.execute("ALTER TABLE trades ADD COLUMN selection_context TEXT")
     if "decision_id" not in columns:
         conn.execute("ALTER TABLE trades ADD COLUMN decision_id TEXT")
+    if "mode" not in columns:
+        conn.execute("ALTER TABLE trades ADD COLUMN mode TEXT DEFAULT 'paper'")
 
     # Context tree tables for multi-layered memory management
     conn.execute(
@@ -167,6 +170,7 @@ def log_trade(
     exchange_code: str = "KRX",
     selection_context: dict[str, any] | None = None,
     decision_id: str | None = None,
+    mode: str = "paper",
 ) -> None:
     """Insert a trade record into the database.
 
@@ -182,6 +186,8 @@ def log_trade(
         market: Market code
         exchange_code: Exchange code
         selection_context: Scanner selection data (RSI, volume_ratio, signal, score)
+        decision_id: Unique decision identifier for audit linking
+        mode: Trading mode ('paper' or 'live') for data separation
     """
     # Serialize selection context to JSON
     context_json = json.dumps(selection_context) if selection_context else None
@@ -190,9 +196,10 @@ def log_trade(
         """
         INSERT INTO trades (
             timestamp, stock_code, action, confidence, rationale,
-            quantity, price, pnl, market, exchange_code, selection_context, decision_id
+            quantity, price, pnl, market, exchange_code, selection_context, decision_id,
+            mode
         )
-        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+        VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
         """,
         (
             datetime.now(UTC).isoformat(),
@@ -207,6 +214,7 @@ def log_trade(
             exchange_code,
             context_json,
             decision_id,
+            mode,
         ),
     )
     conn.commit()

src/main.py

@@ -822,6 +822,7 @@ async def trading_cycle(
         exchange_code=market.exchange_code,
         selection_context=selection_context,
         decision_id=decision_id,
+        mode=settings.MODE if settings else "paper",
     )
 
     # 7. Latency monitoring
@@ -1318,6 +1319,7 @@ async def run_daily_session(
                 market=market.code,
                 exchange_code=market.exchange_code,
                 decision_id=decision_id,
+                mode=settings.MODE,
             )
 
     logger.info("Daily trading session completed")

tests/test_db.py

@@ -58,3 +58,103 @@ def test_get_open_position_returns_none_when_latest_is_sell() -> None:
 def test_get_open_position_returns_none_when_no_trades() -> None:
     conn = init_db(":memory:")
     assert get_open_position(conn, "AAPL", "US_NASDAQ") is None
+
+
+# ---------------------------------------------------------------------------
+# mode column tests (issue #212)
+# ---------------------------------------------------------------------------
+
+
+def test_log_trade_stores_mode_paper() -> None:
+    """log_trade must persist mode='paper' in the trades table."""
+    conn = init_db(":memory:")
+    log_trade(
+        conn=conn,
+        stock_code="005930",
+        action="BUY",
+        confidence=85,
+        rationale="test",
+        mode="paper",
+    )
+    row = conn.execute("SELECT mode FROM trades ORDER BY id DESC LIMIT 1").fetchone()
+    assert row is not None
+    assert row[0] == "paper"
+
+
+def test_log_trade_stores_mode_live() -> None:
+    """log_trade must persist mode='live' in the trades table."""
+    conn = init_db(":memory:")
+    log_trade(
+        conn=conn,
+        stock_code="005930",
+        action="BUY",
+        confidence=85,
+        rationale="test",
+        mode="live",
+    )
+    row = conn.execute("SELECT mode FROM trades ORDER BY id DESC LIMIT 1").fetchone()
+    assert row is not None
+    assert row[0] == "live"
+
+
+def test_log_trade_default_mode_is_paper() -> None:
+    """log_trade without explicit mode must default to 'paper'."""
+    conn = init_db(":memory:")
+    log_trade(
+        conn=conn,
+        stock_code="005930",
+        action="HOLD",
+        confidence=50,
+        rationale="test",
+    )
+    row = conn.execute("SELECT mode FROM trades ORDER BY id DESC LIMIT 1").fetchone()
+    assert row is not None
+    assert row[0] == "paper"
+
+
+def test_mode_column_exists_in_schema() -> None:
+    """trades table must have a mode column after init_db."""
+    conn = init_db(":memory:")
+    cursor = conn.execute("PRAGMA table_info(trades)")
+    columns = {row[1] for row in cursor.fetchall()}
+    assert "mode" in columns
+
+
+def test_mode_migration_adds_column_to_existing_db() -> None:
+    """init_db must add mode column to existing DBs that lack it (migration)."""
+    import tempfile
+    import os
+
+    with tempfile.NamedTemporaryFile(suffix=".db", delete=False) as f:
+        db_path = f.name
+    try:
+        # Create DB without mode column (simulate old schema)
+        import sqlite3
+        old_conn = sqlite3.connect(db_path)
+        old_conn.execute(
+            """CREATE TABLE trades (
+                id INTEGER PRIMARY KEY AUTOINCREMENT,
+                timestamp TEXT NOT NULL,
+                stock_code TEXT NOT NULL,
+                action TEXT NOT NULL,
+                confidence INTEGER NOT NULL,
+                rationale TEXT,
+                quantity INTEGER,
+                price REAL,
+                pnl REAL DEFAULT 0.0,
+                market TEXT DEFAULT 'KR',
+                exchange_code TEXT DEFAULT 'KRX',
+                decision_id TEXT
+            )"""
+        )
+        old_conn.commit()
+        old_conn.close()
+
+        # Run init_db — should add mode column via migration
+        conn = init_db(db_path)
+        cursor = conn.execute("PRAGMA table_info(trades)")
+        columns = {row[1] for row in cursor.fetchall()}
+        assert "mode" in columns
+        conn.close()
+    finally:
+        os.unlink(db_path)