Sorin Petcu (8/7/2008)
what a glitch!!in BOL it says that SQRT ( float_expression )
and float could be, as definition of float,
float - 1.79E+308 to -2.23E-308, 0 and 2.23E-308 to 1.79E+308
so, where it says that the argument of SQRT should be not negative!???
Right. The datatype float is the valid input type for SQRT(), but not all possible values are allowed as input. This is because SQRT(-1) is technically either i or -i, both of which are unexpressable in any native numeric type in SQL. That makes SQL's math "Real" instead of "Complex" and in all Real Math environments, negative numbers are outside of the domain of accpeted input values for SQRT().
Technically you are right, this is not documented in BOL. However, it is documented in the ANSI SQL specs and well understood as a natural limitation of SQRT() in all Real-based languages (LOG() has similar restricitons).
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