如何在sqlserver中将float转换为varchar

尝试使用 STR() 功能。

SELECT STR(float_field, 25, 5)

STR() Function

另一个注意事项:这个垫子在左边有空格。如果这是一个问题,结合 LTRIM

SELECT LTRIM(STR(float_field, 25, 5))

我找到的唯一一个返回与原始数字完全相同的查询位是

CONVERT (VARCHAR(50), float_field,128)

看到了吗 http://www.connectsql.com/2011/04/normal-0-microsoftinternetexplorer4.html

上述其他解决方案有时会舍入或在末尾添加数字

:根据下面的评论和我在 https://msdn.microsoft.com/en-us/library/ms187928.aspx

CONVERT (VARCHAR(50), float_field,3)

应在新的SQL Server版本中使用(Azure SQL数据库,从SQL Server 2016 RC3开始)

这就是我在SQLServer2012中最终使用的解决方案(因为所有其他建议都有截断小数部分的缺点或其他一些缺点)。

declare @float float = 1000000000.1234;
select format(@float, N'#.##############################');

输出:

1000000000.1234

这样做的另一个好处(在我的例子中)是简化和本地化:

select format(@float, N'#,##0.##########', 'de-DE');

输出:

1.000.000.000,1234

有用的话题谢谢。

如果你想像我一样去掉零线,你可以用它:

DECLARE @MyFloat [float];
SET @MyFloat = 1000109360.050;
SELECT REPLACE(RTRIM(REPLACE(REPLACE(RTRIM(LTRIM(REPLACE(STR(@MyFloat, 38, 16), '0', ' '))), ' ', '0'),'.',' ')),' ',',')

float

这不需要四舍五入就有帮助

declare @test float(25)

declare @test1 decimal(10,5)

select @test = 34.0387597207
select @test
set @test1 = convert (decimal(10,5), @test)
select cast((@test1) as varchar(12))


Select  LEFT(cast((@test1) as varchar(12)),LEN(cast((@test1) as varchar(12)))-1)

integer 先是变成一个 string

cast((convert(int,b.tax_id)) as varchar(20))

cast((convert(bigint,b.tax_id)) as varchar(20))

SELECT LTRIM(STR(float_field, 25, 0))

是最好的方法,所以你不添加 .0000 以及值末尾的任何数字。

如果使用CLR函数,则可以将float转换为与float类似的字符串,而无需在末尾添加所有额外的0。

CLR函数

[Microsoft.SqlServer.Server.SqlFunction(DataAccess = DataAccessKind.Read)]
[return: SqlFacet(MaxSize = 50)]
public static SqlString float_to_str(double Value, int TruncAfter)
{
  string rtn1 = Value.ToString("R");
  string rtn2 = Value.ToString("0." + new string('0', TruncAfter));

  if (rtn1.Length < rtn2.Length) { return rtn1; } else { return rtn2; }
}

例子

create table #temp (value float)
insert into #temp values (0.73), (0), (0.63921), (-0.70945), (0.28), (0.72000002861023), (3.7), (-0.01), (0.86), (0.55489), (0.439999997615814)

select value,
       dbo.float_to_str(value, 18) as converted,
       case when value = cast(dbo.float_to_str(value, 18) as float) then 1 else 0 end as same
from   #temp

drop table #temp

.

输出

value                  converted                  same
---------------------- -------------------------- -----------
0.73                   0.73                       1
0                      0                          1
0.63921                0.63921                    1
-0.70945               -0.70945                   1
0.28                   0.28                       1
0.72000002861023       0.72000002861023           1
3.7                    3.7                        1
-0.01                  -0.01                      1
0.86                   0.86                       1
0.55489                0.55489                    1
0.439999997615814      0.439999997615814          1

所有转换的字符串都被截断为18位小数,并且没有尾随的零。18位精度对我们来说不是问题。而且,我们100%的FP数(接近100000个值)看起来与字符串值相同,就像它们在数据库中与FP数一样。

DECLARE @MyFloat [float];
SET @MyFloat = 1000109360.050;

SELECT REPLACE(RTRIM(REPLACE(REPLACE(RTRIM((REPLACE(CAST(CAST(@MyFloat AS DECIMAL(38,18)) AS VARCHAR(max)), '0', ' '))), ' ', '0'),'.',' ')),' ','.')

select replace(myFloat, '', '')

REPLACE() documentation :

如果任何一个参数为NULL,则返回NULL。

测验:
空==>[空]
1.11==>1.11

1.00==>1

-1.10==>-1.1
0.00001==>1e-005
0.000011==>1.1e-005

选择

根据分子生物学的答案:

DECLARE @F FLOAT = 1000000000.1234;
SELECT @F AS Original, CAST(FORMAT(@F, N'#.##############################') AS VARCHAR) AS Formatted;

SET @F = 823399066925.049
SELECT @F AS Original, CAST(@F AS VARCHAR) AS Formatted
UNION ALL SELECT @F AS Original, CONVERT(VARCHAR(128), @F, 128) AS Formatted
UNION ALL SELECT @F AS Original, CAST(FORMAT(@F, N'G') AS VARCHAR) AS Formatted;

SET @F = 0.502184537571209
SELECT @F AS Original, CAST(@F AS VARCHAR) AS Formatted
UNION ALL SELECT @F AS Original, CONVERT(VARCHAR(128), @F, 128) AS Formatted
UNION ALL SELECT @F AS Original, CAST(FORMAT(@F, N'G') AS VARCHAR) AS Formatted;

我刚刚遇到了类似的情况,并对ssmsv17.9.1/sql2017中出现的“非常大的数字”的舍入问题感到惊讶。

我并不是说我有一个解决方案,但是我观察到了 FORMAT 礼物 一个看起来正确的数字。我不能暗示这会减少进一步的舍入问题,或者在复杂的数学函数中是有用的。

提供的SQL代码 应该 清楚地展示我的观察结果,同时允许其他人在需要时测试他们的代码和想法。

WITH Units AS 
(
   SELECT 1.0 AS [RaisedPower] , 'Ten' As UnitDescription
   UNION ALL
   SELECT 2.0 AS [RaisedPower] , 'Hundred' As UnitDescription
   UNION ALL
   SELECT 3.0 AS [RaisedPower] , 'Thousand' As UnitDescription
   UNION ALL
   SELECT 6.0 AS [RaisedPower] , 'Million' As UnitDescription
   UNION ALL
   SELECT 9.0 AS [RaisedPower] , 'Billion' As UnitDescription
   UNION ALL
   SELECT 12.0 AS [RaisedPower] , 'Trillion' As UnitDescription
   UNION ALL
   SELECT 15.0 AS [RaisedPower] , 'Quadrillion' As UnitDescription
   UNION ALL
   SELECT 18.0 AS [RaisedPower] , 'Quintillion' As UnitDescription
   UNION ALL
   SELECT 21.0 AS [RaisedPower] , 'Sextillion' As UnitDescription
   UNION ALL
   SELECT 24.0 AS [RaisedPower] , 'Septillion' As UnitDescription
   UNION ALL
   SELECT 27.0 AS [RaisedPower] , 'Octillion' As UnitDescription
   UNION ALL
   SELECT 30.0 AS [RaisedPower] , 'Nonillion' As UnitDescription
   UNION ALL
   SELECT 33.0  AS [RaisedPower] , 'Decillion' As UnitDescription

)

SELECT UnitDescription

   ,              POWER( CAST(10.0 AS FLOAT(53)) , [RaisedPower] )                                                             AS ReturnsFloat
   ,        CAST( POWER( CAST(10.0 AS FLOAT(53)) , [RaisedPower] )  AS NUMERIC (38,0) )                                        AS RoundingIssues
   , STR(   CAST( POWER( CAST(10.0 AS FLOAT(53)) , [RaisedPower] )  AS NUMERIC (38,0) ) ,   CAST([RaisedPower] AS INT) + 2, 0) AS LessRoundingIssues
   , FORMAT(      POWER( CAST(10.0 AS FLOAT(53)) , [RaisedPower] )  , '0')                                                     AS NicelyFormatted

FROM Units
ORDER BY [RaisedPower]