diff --git a/src/pantry/core/sqlite.go b/src/pantry/core/sqlite.go
index ae8de54..70dec73 100644
--- a/src/pantry/core/sqlite.go
+++ b/src/pantry/core/sqlite.go
@@ -8,12 +8,14 @@ import (
 	_ "modernc.org/sqlite"
 )
 
+// InitDB open or create sqlite db at db path
 func InitDB(path string) (*sql.DB, error) {
 	db, err := sql.Open("sqlite", path)
 	if err != nil {
 		return nil, err
 	}
 
+	// defines schema - one row per item + expiry entry
 	schema := `
 	CREATE TABLE IF NOT EXISTS inventory (
 	id INTEGER PRIMARY KEY AUTOINCREMENT,
@@ -25,6 +27,7 @@ func InitDB(path string) (*sql.DB, error) {
 	);
 	`
 
+	// ensure table exists before continuing
 	_, err = db.Exec(schema)
 	if err != nil {
 		return nil, fmt.Errorf("failed to apply schema %w", err)
@@ -34,17 +37,25 @@ func InitDB(path string) (*sql.DB, error) {
 }
 
 func ListItems(db *sql.DB) ([]InventoryItem, error) {
+	// query all items from inventory table
 	rows, err := db.Query("SELECT name, quantity, unit, expiry, added_at FROM inventory ORDER BY name")
 	if err != nil {
 		return nil, fmt.Errorf("failed to list items: %w", err)
 	}
-	defer rows.Close()
+	// ensure rows are closed cleanly after iteration
+	defer func(rows *sql.Rows) {
+		err := rows.Close()
+		if err != nil {
+
+		}
+	}(rows)
 
 	var items []InventoryItem
 
 	for rows.Next() {
 		var item InventoryItem
-		var expiry sql.NullString
+		// read nullable expiry and parse added_at
+		var expiry sql.NullTime
 		var addedAtStr string
 
 		err = rows.Scan(&item.Name, &item.Quantity, &item.Unit, &expiry, &addedAtStr)
@@ -52,15 +63,14 @@ func ListItems(db *sql.DB) ([]InventoryItem, error) {
 			return nil, fmt.Errorf("failed to scan row: %w", err)
 		}
 
+		// only assign expiry if it was non-null in db
 		if expiry.Valid {
-			parsed, err := time.Parse("2006-01-02", expiry.String)
-			if err != nil {
-				item.Expiry = &parsed
-			}
+			item.Expiry = &expiry.Time
 		}
 
+		// parse added_at from string format
 		parsedTime, err := time.Parse("2006-01-02", addedAtStr)
-		if err != nil {
+		if err == nil {
 			item.AddedAt = parsedTime
 		}
 
@@ -69,3 +79,55 @@ func ListItems(db *sql.DB) ([]InventoryItem, error) {
 
 	return items, nil
 }
+
+func AddItem(db *sql.DB, item InventoryItem) error {
+	var existingID int
+	var existingQty float64
+
+	// check if item with same name + expiry combination exists already
+	// expiry compared with IS ? OR = ? to support null cases
+	query := `
+	SELECT id, quantity FROM Inventory
+	where name = ? AND (expiry IS ? OR expiry = ?)`
+
+	row := db.QueryRow(query, item.Name, item.Quantity, item.Expiry, item.Expiry)
+	err := row.Scan(&existingID, &existingQty)
+
+	// convert expiry into str or nil for sql insert
+	var expiryVal interface{}
+	if item.Expiry != nil {
+		expiryVal = item.Expiry.Format("2006-01-02")
+	} else {
+		expiryVal = nil
+	}
+	addedAt := item.AddedAt.Format("2006-01-02")
+
+	switch {
+	// no match found - insert new item
+	case err == sql.ErrNoRows:
+		_, err = db.Exec(`
+			INSERT INTO inventory (name, quantity, unit, expiry, added_at)
+			VALUES (?, ?, ?, ?, ?)`,
+			item.Name, item.Quantity, item.Unit, expiryVal, addedAt)
+		if err != nil {
+			return fmt.Errorf("failed to add item: %w", err)
+		}
+
+		fmt.Printf("added %s, quantity: %.2f %s\n", item.Name, item.Quantity, item.Unit)
+		return nil
+
+	// error during lookup (let's hope not)
+	case err != nil:
+		return fmt.Errorf("failed to add item: %w", err)
+
+	// db match found, update quantity
+	default:
+		newQty := existingQty + item.Quantity
+		_, err := db.Exec(`UPDATE Inventory SET quantity = ? WHERE id = ?`, newQty, existingID)
+		if err != nil {
+			return fmt.Errorf("failed to add item: %w", err)
+		}
+		fmt.Printf("updated %s, quantity: %.2f %s\n", item.Name, item.Quantity, item.Unit)
+		return nil
+	}
+}
diff --git a/src/pantry/main.go b/src/pantry/main.go
index ef47940..eb1a8ce 100644
--- a/src/pantry/main.go
+++ b/src/pantry/main.go
@@ -146,6 +146,45 @@ func main() {
 			fmt.Printf("- %s: %.2f %s (%s)\n", item.Name, item.Quantity, item.Unit, util.DaysUntilExpiry(item.Expiry))
 		}
 
+	case "add-db":
+		if len(os.Args) < 5 {
+			fmt.Println("Usage: inventory add [name] [quantity] [unit] [expiry:YYYY-MM-DD]")
+			return
+		}
+
+		name := os.Args[2]
+
+		quantity, err := strconv.ParseFloat(os.Args[3], 64)
+		if err != nil {
+			fmt.Println("Invalid quantity")
+			return
+		}
+
+		unit := os.Args[4]
+
+		var expiry *time.Time
+		if len(os.Args) >= 6 {
+			parsed, err := time.Parse("2006-01-02", os.Args[5])
+			if err != nil {
+				fmt.Println("Invalid expiry date format. Expected YYYY-MM-DD")
+				return
+			}
+			expiry = &parsed
+		}
+
+		item := core.InventoryItem{
+			Name:     name,
+			Quantity: quantity,
+			Unit:     unit,
+			Expiry:   expiry,
+			AddedAt:  time.Now(),
+		}
+
+		err = core.AddItem(db, item)
+		if err != nil {
+			fmt.Println("Failed to add item:", err)
+		}
+
 	default:
 		fmt.Println("Unknown command:", command)
 	}