I'm working on a view which selects a large text field from another table. (No, not the snapshots.) This table contains an errorlog from the web application that provides access to it. However, this errorlog contains some very long texts which cause the column to be extremely wide.
So I want to select the text field, but any word longer than 20 characters must be replaced to the first three, an ellipse (...) and the last three letters. Example: - System.Web.HttpException: The client
disconnected. --->
System.Web.UI.ViewStateException:
Invalid viewstate. Client IP:
xxx.xxx.xxx.xxx Port: xxxx
User-Agent: Mozilla/4.0 (compatible;
MSIE 7.0; Windows NT 6.1; WOW64;
Trident/4.0; SLCC2; .NET CLR
2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; InfoPath.3; .NET4.0C;
.NET4.0E) ViewState:
T89RiGYTOALETOKughad85KzoDRo/ut3Vlnd1qECsYf1t9GGNilDrvbRn8l45SVX8AsZrs6zyEngk8MKdpoRecI4j0X5IsmI0Deldf4nLKNlLoE4xaOoMUlj7hTFRXAvqyOFSvzsvyhwpWCLuG26RJT4YbGr1IJYgqWX9KVplIdasDUR0aNNMvD9FVa8Fi33Ny7fuIjxPKMpqKByKYJtAgZU4PIji88MMQWQDMNZmBxM965+bN+RsvTSxrGWzLLhzFCrK0LeCCrZeRQyncmMhUPGM9YB1+UapRfeca3R4vCacN6vv/UnZekBXP5rzAvDgJB9RGgXKhhdBVeCCD3h2N6X5RxKKLdy76h3AVZ8H8DfJpdjvre8ExNdkHeCOZWz0EjyX9hNMe2KZ2+gmEQaFi/mNJ5nZzCjOCfYsdbwAorpEGBZNqX9gBjDs32e8Admgdk+zvxl3Mt4pF3e6zTh45N1cCjBNCLya6Rd9d9mfiPM6DFbXUBiXw8dbZmT/6veCw0YPfRCjKCod3D7+Kva44RuiIkKIIqr0vPLLlja/ggH/4iHq9SqgOpwGJuoHGfy++5G14bIv3Zyzm8Vj+re3iMfbwZCUI4sCeFy7L7I6NrL27pd+6Qz60WAMv6lPl3Y88J5CUIVAIZqINsOt5htisTf00+d0pFptx5wwlmprzm1dVfXcL/0x3BPvlNDof5aW+PJxAP19SHR+PUuAEm9YO0ZmhGg+L5+DN2kuHSpQFpwC6FxCzVdicxlR8+x4jUy2+Fxeblabla
This mus开发者_开发技巧t become:
- System.Web.HttpException: The client
disconnected. --->
System.Web.UI.ViewStateException:
Invalid viewstate. Client IP:
xxx.xxx.xxx.xxx Port: xxxx
User-Agent: Mozilla/4.0 (compatible;
MSIE 7.0; Windows NT 6.1; WOW64;
Trident/4.0; SLCC2; .NET CLR
2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; InfoPath.3; .NET4.0C;
.NET4.0E) ViewState: T89...bla
And yes, that first text is extremely wide... Even SO has trouble displaying it correctly. :-)
So, I probably need to do something with regular expressions or whatever. Thus: SELECT REGEX(Something, something, something) FROM MyTable; or whatever.Is it possible?Maybe this will help
CREATE FUNCTION dbo.EllipseTextWords(@Text VARCHAR(MAX), @EllipsedSize INT, @Separator AS VARCHAR(1), @EllipsisLength INT = 3)
RETURNS VARCHAR(MAX)
AS
BEGIN
DECLARE @Tokens TABLE
(
Token VARCHAR(MAX)
)
WHILE (CHARINDEX(@Separator, @Text) > 0)
BEGIN
INSERT INTO @Tokens
SELECT LTRIM(RTRIM(SUBSTRING(@Text, 1, CHARINDEX(@Separator, @Text) - 1)))
SET @Text = SUBSTRING(@Text, CHARINDEX(@Separator, @Text) + 1, LEN(@Text))
END
INSERT INTO @Tokens
SELECT LTRIM(RTRIM(@Text))
UPDATE @Tokens SET Token = LEFT(Token, @EllipsisLength) + '...' + RIGHT(Token, @EllipsisLength) WHERE Token <> '' AND LEN(Token) > LEN(LEFT(Token, @EllipsedSize))
DECLARE @Ellipsed VARCHAR(MAX)
SELECT @Ellipsed = COALESCE(@Ellipsed + @Separator, '') + Token FROM @Tokens
RETURN @Ellipsed
END
then you coul call the created function
SELECT dbo.EllipseTextWords(Details, 20, ' ', DEFAULT) FROM ErrorLog
but I wonder why dont you do it in the presentation layer.
How about the following solution. Assuming your table containing the errorlog is called ErrorLog
and has a column Details
which holds the large text you're referring to.
Create a special function that would split text content into words (took it from here but essentially any similar function will work):
CREATE FUNCTION dbo.Split(@String varchar(8000), @Delimiter char(1)) returns @temptable TABLE (items varchar(8000)) as begin declare @idx int declare @slice varchar(8000) select @idx = 1 if len(@String) < 1 or @String is null return while @idx != 0 begin set @idx = charindex(@Delimiter, @String) if @idx != 0 set @slice = left(@String, @idx - 1) else set @slice = @String if(len(@slice) > 0) insert into @temptable(Items) values(@slice) set @String = right(@String, len(@String) - @idx) if len(@String) = 0 break end return end
Then retrieve the text field from the ErrorLog table using the query below (basically, it iterates through all words, examines the length of each item and then concatenate them into a new string):
SELECT ( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( REPLACE( (SELECT (CASE WHEN LEN(items) > 50 THEN LEFT(items, 3) + '...' + RIGHT(items, 3) ELSE items END) + ' ' FROM dbo.Split(ErrorLog.Details, ' ') FOR XML PATH ('')) ,'&','&') ,'<','<') ,'>','>') ,'
',char(10)) ,'
',char(13)) ,'	',char(9)) ) AS Details FROM ErrorLog
Please note that I use 50 as a threshold value because otherwise it will also cut items like 'System.Web.HttpException' which have length > 20.
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