SELECT COALESCE(A,B,C,'NA') FROM XXXXX --判断A若为空则取B，B为空这取C，C为空则取默认值'NA' 相关文章： 2021-08-25 2021-08-21 2022-12-23 2022-12-23 2022-12-23 2022-12-23 2021-08-09