标签:compare null equal value say operator NULL my
https://stackoverflow.com/questions/5658457/not-equal-operator-on-null
<>
is Standard SQL-92; !=
is its equivalent. Both evaluate for values, which NULL
is not -- NULL
is a placeholder to say there is the absence of a value.
Which is why you can only use IS NULL
/IS NOT NULL
as predicates for such situations.
This behavior is not specific to SQL Server. All standards-compliant SQL dialects work the same way.
Note: To compare if your value is not null, you use IS NOT NULL
, while to compare with not null value, you use <> 'YOUR_VALUE'
. I can't say if my value equals or not equals to NULL, but I can say if my value is NULL or NOT NULL. I can compare if my value is something other than NULL.
标签:compare,null,equal,value,say,operator,NULL,my 来源: https://www.cnblogs.com/chucklu/p/12091082.html
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