Sql where clause not equal to null

Collectives on Stack Overflow. Learn more. Asked 6 years ago. Active 6 years ago. Viewed 15k times. Improve this question. Dylan Czenski Dylan Czenski 1, 3 3 gold badges 22 22 silver badges 45 45 bronze badges. Add a comment. Active Oldest Votes. SQL's coalesce turns a null value into another value. The example returns the result of the expression, unless it is null , then it returns zero 0. Is Null and IsNull both find null values, but you won't use them in the same way. It can be used as a worksheet function WS in Excel.

The is. In computer programming , null is both a value and a pointer. Null is a built-in constant that has a value of zero. It is the same as the character 0 used to terminate strings in C. Null can also be the value of a pointer, which is the same as zero unless the CPU supports a special bit pattern for a null pointer.

This function is used to replace NULL value with another value. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Ask Question. Asked 10 years, 7 months ago. Active 2 years, 2 months ago. Viewed k times. Is it possible to negate a where clause? Improve this question. Frank Vilea Frank Vilea 7, 20 20 gold badges 61 61 silver badges 86 86 bronze badges. FYI, id!

Add a comment. Active Oldest Votes. There could, however, be other criteria that would use indexing and allow set based filtering. The compiler needs to evaluate the whole predicate, it does not use short-circuit when evaluating expressions. The main reason is that it needs as much information as it can before evaluating statistics, indexes, logical and physical operators to be used to satidfy the query. Another option, and I think somebody mentioned before, is to create a calculated column, and create and index by it.

If the value is selective enough, then the optimizer could opt for using the index. I think that I understand your concerns. However, as presented,. EVERY row has to be evaluated. Both sides of the AND are tested. You could, perhaps use a nested CASE structure -but I doubt if that would actually save any processing time. There is no guarantee that the database engine will evaluate [AND] criteria in any particular order.

I also didn't realize the query analyzer will NOT short circuit logical statements.