IF ( IS NOT NULL AND IS NULL) BEGIN SET = 0 IF ( IS NULL AND IS NOT NULL) BEGIN SET = 0 Since SQL Server doesn’t have this kind of operator, the typical solution is to use two separate conditions, for example:ĬONVERT( nvarchar, SQL_VARIANT_PROPERTY( ' BaseType')) Long story short: before using this, think about the situation carefully and if you still are convinced that this is the correct way, then hopefully this article saves some work. In such a case, this comparison may simplify the query building process. In suchĪn application, null along any other value may be a valid criteria defined by the user to find records. One example could be a reporting application where dynamic conditions are used. That there still are cases where this kind of comparison may be justified. One reason was to raise discussions about null equality and the other was So why write this article at all? I thought about it a lot before publishing this. When found, it should be fixed if possible. Null matches a null, the best thing is to sit down, put your legs on the table, and figure out the root cause. Typically, if you need to find records where Since the real value of null is unknown, any comparison result is unknown by definition, we simply don't know the result.įrom a design point of view, null represents a missing piece of information and it should always be handled that way. To be more specific, they are not unequal either, one null is never less than another ![]() When comparingĪ null to a null, they are not equal, ever. So why is null handled differently from other values anyway? ANSI standard defines a null value as unknown. The difference from the normal equal to operator is that if both of the operands are null, the result is 1 instead of null. ![]() The operator compares two values and if they are identical, returns 1. MySQL has a non-standard extension to operators called null-safe equal to operator.
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