CREATE TABLE IF NOT EXISTS `lims_value_binding` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `template_id` int(11) NOT NULL,
  `mapping_id` int(11) NOT NULL,
  `field_id` int(11) NOT NULL,
  `source_value` varchar(500) NOT NULL,
  `source_key` varchar(500) NOT NULL,
  `lims_value_id` int(11) NOT NULL,
  `lims_value` varchar(500) DEFAULT NULL,
  `created_by` int(11) DEFAULT NULL,
  `created_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  UNIQUE KEY `uq_mapping_source` (`mapping_id`, `source_key`),
  KEY `idx_template` (`template_id`),
  KEY `idx_field_source` (`field_id`, `source_key`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;