-- Add symbol column to orders table for multi-crypto support
-- Run this migration to enable support for multiple cryptocurrencies

ALTER TABLE orders 
ADD COLUMN symbol VARCHAR(20) NOT NULL DEFAULT 'BTCUSD' AFTER id;

-- Add index for faster queries by symbol
CREATE INDEX idx_orders_symbol ON orders(symbol);

-- Update existing records (if any) to have BTCUSD as default
UPDATE orders SET symbol = 'BTCUSD' WHERE symbol IS NULL OR symbol = '';