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?
另一个UDF，希望足够通用，并且不假设你是否想四舍五入到一个特定的小数点后数位:
CREATE FUNCTION [dbo].[fn_FormatNumber] (@number decimal(38,18))
RETURNS varchar(50)
BEGIN
-- remove minus sign before applying thousands seperator
DECLARE @negative bit
SET @negative = CASE WHEN @number < 0 THEN 1 ELSE 0 END
SET @number = ABS(@number)
-- add thousands seperator for every 3 digits to the left of the decimal place
DECLARE @pos int, @result varchar(50) = CAST(@number AS varchar(50))
SELECT @pos = CHARINDEX('.', @result)
WHILE @pos > 4
BEGIN
SET @result = STUFF(@result, @pos-3, 0, ',')
SELECT @pos = CHARINDEX(',', @result)
END
-- remove trailing zeros
WHILE RIGHT(@result, 1) = '0'
SET @result = LEFT(@result, LEN(@result)-1)
-- remove decimal place if not required
IF RIGHT(@result, 1) = '.'
SET @result = LEFT(@result, LEN(@result)-1)
IF @negative = 1
SET @result = '-' + @result
RETURN @result
END
对于2012年以前不包含FORMAT函数的SQL Server，创建如下函数:
CREATE FUNCTION FormatCurrency(@value numeric(30,2))
RETURNS varchar(50)
AS
BEGIN
DECLARE @NumAsChar VARCHAR(50)
SET @NumAsChar = '$' + CONVERT(varchar(50), CAST(@Value AS money),1)
RETURN @NumAsChar
END
选择dbo.FormatCurrency (12345678)
返回12345678美元
如果你只想要逗号，就去掉$。
另一个UDF，希望足够通用，并且不假设你是否想四舍五入到一个特定的小数点后数位:
CREATE FUNCTION [dbo].[fn_FormatNumber] (@number decimal(38,18))
RETURNS varchar(50)
BEGIN
-- remove minus sign before applying thousands seperator
DECLARE @negative bit
SET @negative = CASE WHEN @number < 0 THEN 1 ELSE 0 END
SET @number = ABS(@number)
-- add thousands seperator for every 3 digits to the left of the decimal place
DECLARE @pos int, @result varchar(50) = CAST(@number AS varchar(50))
SELECT @pos = CHARINDEX('.', @result)
WHILE @pos > 4
BEGIN
SET @result = STUFF(@result, @pos-3, 0, ',')
SELECT @pos = CHARINDEX(',', @result)
END
-- remove trailing zeros
WHILE RIGHT(@result, 1) = '0'
SET @result = LEFT(@result, LEN(@result)-1)
-- remove decimal place if not required
IF RIGHT(@result, 1) = '.'
SET @result = LEFT(@result, LEN(@result)-1)
IF @negative = 1
SET @result = '-' + @result
RETURN @result
END
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
