用mssql怎样实现这样的效果

下面是计算当前积分的sql语句：如果记录为null时显示0

select isnull('0',(b.sumpoints - a.usedpoints)) as points

结果：所有记录都显示 0

如果：
select (b.sumpoints - a.usedpoints) as points
却出现null
请问怎样将这些null变成0呢？

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select isnull((b.sumpoints - a.usedpoints), 0) as points

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isnull((b.sumpoints - a.usedpoints), 0)

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SQL code:
select isnull((b.sumpoints - a.usedpoints),0) as points

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引用

下面是计算当前积分的sql语句：如果记录为null时显示0

select isnull('0',(b.sumpoints - a.usedpoints)) as points

结果：所有记录都显示 0

如果：
select (b.sumpoints - a.usedpoints) as points
却出现null
请问怎样将这些null变成0呢？

顺序反了，楼上正解

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SQL code:


isnull((b.sumpoints - a.usedpoints), 0)

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顺序写反了isnull((b.sumpoints - a.usedpoints), 0)