SIGN(numeric_expression)
Returns the positive (+1), negative (-1), or zero (0) sign of a numeric expression. Returns NULL if the argument is NULL.
REVERSE
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转载于:https://www.cnblogs.com/end/archive/2011/01/28/1946888.html
SIGN(numeric_expression)
Returns the positive (+1), negative (-1), or zero (0) sign of a numeric expression. Returns NULL if the argument is NULL.
REVERSE
转载于:https://www.cnblogs.com/end/archive/2011/01/28/1946888.html