I'm running some administrative queries and compiling results from sp_spaceused in SQL Server 2008 to look at data/index space ratios of some tables in my database. Of course I am getting all sorts of large numbers in the results and my eyes are starting to gloss over. It would be really convenient if I could format all those numbers with commas (987654321 becomes 987,654,321). Funny that in all the many years I've used SQL Server, this issue has never come up since most of the time I would be doing formatting at the presentation layer, but in this case the T-SQL result in SSMS is the presentation.
我考虑过只创建一个简单的CLR UDF来解决这个问题，但似乎这应该可以在普通的旧T-SQL中完成。所以，我将在这里提出一个问题-如何在香草T-SQL中进行数字格式化?
这里是我使用的标量函数，它修复了前面示例(上面)中的一些错误，还处理十进制值(指定的数字#)(编辑后也可用于0和负数)。另外需要注意的是，上面的转换为money方法仅限于money数据类型的大小，并且不适用于4(或更多)位小数。这种方法确实更简单，但不太灵活。
CREATE FUNCTION [dbo].[fnNumericWithCommas](@num decimal(38, 18), @decimals int = 4) RETURNS varchar(44) AS
BEGIN
DECLARE @ret varchar(44)
DECLARE @negative bit; SET @negative = CASE WHEN @num < 0 THEN 1 ELSE 0 END
SET @num = abs(round(@num, @decimals)) -- round the value to the number of decimals desired
DECLARE @decValue varchar(18); SET @decValue = substring(ltrim(@num - round(@num, 0, 1)) + '000000000000000000', 3, @decimals)
SET @num = round(@num, 0, 1) -- truncate the incoming number of any decimals
WHILE @num > 0 BEGIN
SET @ret = str(@num % 1000, 3, 0) + isnull(','+@ret, '')
SET @num = round(@num / 1000, 0, 1)
END
SET @ret = isnull(replace(ltrim(@ret), ' ', '0'), '0') + '.' + @decValue
IF (@negative = 1) SET @ret = '-' + @ret
RETURN @ret
END
GO
对于SQL Server 2012+实现，您将能够使用FORMAT将字符串格式应用于非字符串数据类型。
在最初的问题中，用户要求能够使用逗号作为千位分隔符。在一个封闭的重复问题中，用户询问他们如何应用货币格式。下面的查询显示了如何执行这两个任务。它还演示了区域性的应用，以使其成为更通用的解决方案(解决Tsiridis Dimitris应用希腊特殊格式的功能)
-- FORMAT
-- http://msdn.microsoft.com/en-us/library/hh213505(v=sql.110).aspx
-- FORMAT does not do conversion, that's the domain of cast/convert/parse etc
-- Only accepts numeric and date/time data types for formatting.
--
-- Formatting Types
-- http://msdn.microsoft.com/en-us/library/26etazsy.aspx
-- Standard numeric format strings
-- http://msdn.microsoft.com/en-us/library/dwhawy9k.aspx
SELECT
-- c => currency
-- n => numeric
FORMAT(987654321, N'N', C.culture) AS some_number
, FORMAT(987654321, N'c', C.culture) AS some_currency
, C.culture
FROM
(
-- Language culture names
-- http://msdn.microsoft.com/en-us/library/ee825488(v=cs.20).aspx
VALUES
('en-US')
, ('en-GB')
, ('ja-JP')
, ('Ro-RO')
, ('el-GR')
) C (culture);
SQLFiddle用于上面
