-- 表：wms_picking_task_item
-- 用途：拣货任务明细。按库位给出的应拣与实拣数量。
-- 约定：InnoDB / utf8mb4 / 无外键，表间按业务编码关联。详见 docs/database/00-conventions.md
-- 说明：实拣确认时 reserved 转为 picked，并回写出库明细。按 pick_sequence 生成行序。

CREATE TABLE `wms_picking_task_item` (
  `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '内部主键',
  `tenant_code` VARCHAR(32) NOT NULL COMMENT '租户编码',
  `picking_no` VARCHAR(64) NOT NULL COMMENT '拣货单号',
  `line_no` INT UNSIGNED NOT NULL COMMENT '行号',
  `outbound_no` VARCHAR(64) NOT NULL COMMENT '出库单号',
  `allocation_no` VARCHAR(64) NOT NULL COMMENT '分配单号',
  `location_code` VARCHAR(64) NOT NULL COMMENT '库位编码',
  `sku_code` VARCHAR(64) NOT NULL COMMENT 'SKU 编码',
  `batch_no` VARCHAR(64) NOT NULL DEFAULT '' COMMENT '批次号，可空',
  `qty_required` DECIMAL(16,4) NOT NULL DEFAULT 0.0000 COMMENT '应拣数量',
  `qty_picked` DECIMAL(16,4) NOT NULL DEFAULT 0.0000 COMMENT '实拣数量',
  `created_at` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) COMMENT '创建时间',
  `updated_at` DATETIME(3) NOT NULL DEFAULT CURRENT_TIMESTAMP(3) ON UPDATE CURRENT_TIMESTAMP(3) COMMENT '更新时间',
  PRIMARY KEY (`id`),
  UNIQUE KEY `uk_tenant_picking_line` (`tenant_code`, `picking_no`, `line_no`),
  KEY `idx_tenant_outbound` (`tenant_code`, `outbound_no`),
  KEY `idx_tenant_allocation` (`tenant_code`, `allocation_no`),
  CONSTRAINT `chk_picking_qty` CHECK (`qty_required` > 0 AND `qty_picked` >= 0 AND `qty_picked` <= `qty_required`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='拣货任务明细';