select COALESCE(字段,赋值) as c,* from table
SELECT CASE WHEN LENGTH(字段)>0 THEN 字段 ELSE 赋值 END from table
字段类型转换
cast(字段 as 类型)
select COALESCE(字段,赋值) as c,* from table
SELECT CASE WHEN LENGTH(字段)>0 THEN 字段 ELSE 赋值 END from table
字段类型转换
cast(字段 as 类型)