Mysql 查询负数显示为0

需求：库存上报有些为负数，需显示为0

解决：用SELECT CASE WHEN a(字段名)< 0 THEN 0 ELSE a END a

表数据：

SELECT
    ID, 
    EQUIP_NO, 
    EQUIP_NAME, 
    STORAGE_NO, 
    DRUG_ID, 
    DRUG_NAME, 
    CURRENT_HEIGHT, 
    STATUS, 
    CASE WHEN QUANTITY < 0 THEN 0 ELSE QUANTITY END  QUANTITY, 
    PALLET_TYPE, 
    INDEX_NO, 
    VALID_DATE, 
    LOT_NO
FROM eq_equipment_storage_drugs
WHERE 1 = 1

 执行sql运行结果为