附加三个VARCHAR（MAX）变量 [英] Append Three VARCHAR(MAX) variables

问题描述

DECLARE @FileBody1         VARCHAR(max)
            ,@FileBody2         VARCHAR(max)
            ,@FileBody3         VARCHAR(max)
            ,@StartingIndex     INT
            ,@FileLength        INT


    SET @StartingIndex = 1
    SELECT  @FileLength = DATALENGTH(DC.FileBody) FROM Configuration DC WHERE DC.ID = 1
    SELECT @FileBody1 = SUBSTRING(DC.FileBody,@StartingIndex,8000)FROM Configuration DC WHERE DC.ID = 1
    SET @StartingIndex = @StartingIndex + 8000
    SELECT @FileBody2 = SUBSTRING(DC.FileBody,@StartingIndex,8000) FROM Configuration DC WHERE DC.ID = 1
    SET @StartingIndex = @StartingIndex + 8000
    SELECT @FileBody3 = SUBSTRING(DC.FileBody,@StartingIndex,8000) FROM Configuration DC WHERE DC.ID = 1

select @FileBody1+''+@FileBody2+''+@FileBody3

推荐答案

你不能在实践中这样做，或者至少你不应该'' t。

想一想：如果你有两个字符串可以是一个字符串的最大长度，那么如果连接它们，结果可以有多长？答案：字符串最大长度的两倍......

You can''t in practice do that, or at least you shouldn''t.
Think about it: If you have two strings which can be the maximum length for a string, how long a string can the result be if you concatenate them? Answer: twice the maximum length of a string...

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