怎么给空值赋值_Sql Server

如何给空值赋值？
select sum(F_User_point) as gjpoint from TB_CDR where Calling_Station_Id='0411990005'
and Called_Station_Id like '00%'
and convert (varchar(10),convert(dateTime, h323_connect_Time),112) like '200803%'
如何在上面的语句里的gjpoint如果为空的话，就给gjpoint赋一个０的值？

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SQL code

select ISNULL(sum(F_User_point),0) as gjpoint FROM ...
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select isnull(sum(F_User_point),0) as gjpoint from TB_CDR where Calling_Station_Id='0411990005' 
and Called_Station_Id like '00%' 
and convert (varchar(10),convert(dateTime, h323_connect_Time),112) like '200803%'
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ISNULL(sum(F_User_point),0) as gjpoint
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SQL codeselect 'gjpoint'=isnull(sum(F_User_point),0)from TB_CDRwhere Calling_Station_Id='0411990005' and Called_Station_Id like '00%'      and convert (varchar(10),convert(dateTime, h323_connect_Time),112) like '200803%'
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SQL codeselect isnull(sum(F_User_point),0) as gjpoint from TB_CDR where Calling_Station_Id='0411990005' and Called_Station_Id like '00%' and convert (varchar(10),convert(dateTime, h323_connect_Time),112) like '200803%'  --或者select case when sum(F_User_point) is null then 0 else sum(F_User_point) end as gjpoint from TB_CDR where Calling_Station_Id='0411990005' and Called_Station_Id like '00%' and convert (varchar(10),convert(dateTime, h323_connect_Time),112) like '200803%'
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解决就结贴。
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用函数isnull(col,0)
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探讨
解决了　谢谢各位了

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SQL codeselect isnull(sum(F_User_point),0) as gjpoint 
from TB_CDR where Calling_Station_Id='0411990005' 
and Called_Station_Id like '00%' 
and convert (varchar(10),convert(dateTime, h323_connect_Time),112) like '200803%'  

--或者

select case when sum(F_User_point) is null then 0 else sum(F_User_point) end as gjpoint 
from TB_CDR where Calling_Station_Id='0411990005' 
and Called_Stati…