-- prc_billing_task add customer_code for customer filter / rebill
SET NAMES utf8mb4;

SET @col := (
  SELECT COLUMN_NAME FROM information_schema.COLUMNS
  WHERE TABLE_SCHEMA = DATABASE()
    AND TABLE_NAME = 'prc_billing_task'
    AND COLUMN_NAME = 'customer_code'
  LIMIT 1
);
SET @sql := IF(
  @col IS NULL,
  CONCAT(
    'ALTER TABLE prc_billing_task ADD COLUMN customer_code varchar(50) COLLATE utf8mb4_unicode_ci DEFAULT NULL COMMENT ',
    CHAR(39), '客户代码', CHAR(39),
    ' AFTER order_no, ADD KEY idx_billing_task_customer (customer_code)'
  ),
  'SELECT 1'
);
PREPARE stmt FROM @sql; EXECUTE stmt; DEALLOCATE PREPARE stmt;

UPDATE prc_billing_task t
INNER JOIN prc_order_bill b ON b.bill_id = t.bill_id
SET t.customer_code = b.customer_code
WHERE (t.customer_code IS NULL OR t.customer_code = '')
  AND b.customer_code IS NOT NULL AND b.customer_code <> '';