SQL中的FirstName,LastName太复杂了？

Question

这个SQL看起来很复杂,当一个或两个字段都可以为NULL时,有更简单的方法来获取FirstName,LastName吗？

SELECT COALESCE(LastName,'')+
       CASE WHEN LastName+FirstName IS NOT NULL THEN ', ' END+
       COALESCE(FirstName,'') AS Name
FROM Person

Answer 1

怎么样

SELECT COALESCE(LastName + ', ' + FirstName, 
                LastName, FirstName) Name
FROM Person

如果firstname或者lastname为null,整个第一个表达式(带有,),变为null,强制coalesce检查,第二个,lastname单独,然后if lastname为null,最后,firstname单独.