Description:
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Currently NULL values when used as arguments of math and comparision operations are simply converted to zero. So there is no difference between using NULL, false, 0 - this is a useless redundancy while important functionality is missing - to tread NULL values as SQL treats them.

For example:
NULL * $anything should be NULL, instead of 0
NULL + $anything should be NULL, instead of $anything
NULL == NULL should be false, while NULL === NULL should be true

If PHP has NULL value it should be used properly.

Expected result:
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see above