我得到'data is null'异常 [英] I get 'data is null' exception
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问题描述
在下面的代码中,我得到了异常'Data is Null。无法在Null值上调用此方法或属性。'at line if(reader1 ...)
In the following code I get the exception 'Data is Null. This method or property cannot be called on Null values.' at line if(reader1...)
while (reader1.Read())
if(reader1.GetDateTime(9) !=null)
推荐答案
您好,
我认为你的读者1没有价值。请检查是否有。然后回来。
或者,读者1上没什么可读的。
谢谢。
Hi,
I think your reader1 doesn't have a value. Please check if it has. Then come back.
Or, there's nothing to read on reader1.
Thanks.
试试这个
int x = reader.GetOrdinal(datefield);
if(!reader) .IsDBNull(x))
dateValue = reader.GetDateTime(x);
Try this
int x = reader.GetOrdinal("datefield");
if(!reader.IsDBNull(x))
dateValue = reader.GetDateTime(x);
这里只有当reader1不包含任何值时才会出现异常。但是你在循环时检查这个。所以修改你的代码如下:
Here the exception comes only if the reader1 doesn't contain any value . But you are checking this while while loop . So modify your code as below :
while (reader1.Read())
{
if(reader1.GetDateTime(9) !=null)
//你的逻辑在这里
}
//your logic here
}
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