四舍五入，精一位小(分了，以后)
A ：Decimal(18,6)
59.1499569 = 59.1
25.34999394 =25.3
49.49997474 =49.5


[解决办法]
select str( '59.1499569 ',4,1)
select str( '25.34999394 ',4,1)
select str( '49.49997474 ',4,1)