mybatis实用操作—— @MapKey

在mybatis中，可以将list集合转成map返回。用到注解：

 @MapKey("wiKey")
    Map summaryCurrentStore(@Param("storeId")Long storeId,
                                                               @Param("customerId") Long customerId,
                                                               @Param("skuIdSet") Set skuIdSet);

        select
        concat(customer_id,'-',store_id,'-',sku_id) wiKey,
        sum(total_store) changeBeforeTotal,
        sum(occ_store) changeBeforeOcc,
        sum(frozen_store) changeBeforeFrozen,
        sum(apply_store) changeBeforeApply,
        store_id storeId,
        customer_id customerId,
        sku_id skuId
        from warehouse_inventory
        
            store_id = #{storeId,jdbcType=BIGINT}
            and customer_id = #{customerId,jdbcType=BIGINT}
            
                and sku_id in
                
                    #{item,jdbcType=BIGINT}
                
            
        
        group by customer_id,store_id,sku_id

    



        
        
        
        
        
        
        
        
        
    

如果不加 @MapKey("wiKey")，就会报错;

java.lang.ClassCastException: com.runlion.sat.wms.vo.WarehouseInventoryLogMapVO cannot be cast to java.util.Map。

其实直接返回List也可以，然后实用jdk8流的map操作也可以。