CREATE FUNCTION dbo.fnBinaryFloat2Float
(
@BinaryFloat BINARY(8)
)
RETURNS FLOAT
AS
BEGIN
DECLARE @Part TINYINT,
@PartValue TINYINT,
@Mask TINYINT,
@Mantissa FLOAT,
@Exponent SMALLINT,
@Bit TINYINT,
@Ln2 FLOAT,
@BigValue BIGINT
SELECT @Part = 1,
@Mantissa = 1,
@Bit = 1,
@Ln2 = LOG(2),
@BigValue = CAST(@BinaryFloat AS BIGINT),
@Exponent = (@BigValue & 0x7ff0000000000000) / EXP(52 * @Ln2)
WHILE @Part <= 8
BEGIN
SELECT @Part = @Part + 1,
@PartValue = CAST(SUBSTRING(@BinaryFloat, @Part, 1) AS TINYINT),
@Mask = CASE WHEN @Part = 2 THEN 8 ELSE 128 END
WHILE @Mask > 0
BEGIN
IF @PartValue & @Mask > 0
SET @Mantissa = @Mantissa + EXP(-@Bit * @Ln2)
SELECT @Bit = @Bit + 1,
@Mask = @Mask / 2
END
END
RETURN SIGN(@BigValue) * @Mantissa * POWER(CAST(2 AS FLOAT), @Exponent - 1023)
END
不太懂他的算法，不好改
解决了就好
我是有分行的,怎么分行符没了呢!
