4 
PRINT Convert(VarChar(Max),Replicate('1234567890 ',1000))

这将返回到窗口 7,997 个字符。

SELECT Convert(VarChar(Max),Replicate('1234567890 ',1000))

这将返回到网格 7,996 个字符。打印窗口中的额外字符是 CRLF。我有这样的选择：工具→选项→查询结果→结果到文本→每列中显示的最大字符数= 8192

因此，我希望在网格中返回 8,192 个字符，并且希望在我的窗口中返回 11,001 个字符。

然后是这个测试：

DECLARE @VarCharMax VarChar(Max)
SET @VarCharMax = Replicate('123456',2000)
SELECT Right(@VarCharMax,3) -- returns 456
SELECT Right(Left(@VarCharMax,8000),3) -- returns 456
SELECT Right(Left(@VarCharMax,7999),3) -- returns 456
SELECT Right(Left(@VarCharMax,7998),3) -- returns 456
SELECT Right(Left(@VarCharMax,7997),3) -- returns 345
SELECT Right(Left(@VarCharMax,7996),3) -- returns 234

我在这里的理解中缺少什么？它似乎根本不像我预期的那样表现？

4

4 回答 4

4

8000 个字符是复制函数的限制，除非参数是 varchar(max)/nvarchar(max) 类型

https://msdn.microsoft.com/en-us/library/ms174383.aspx

如果 string_expression 不是 varchar(max) 或 nvarchar(max) 类型，则 REPLICATE 将返回值截断为 8,000 字节。要返回大于 8,000 字节的值，必须将 string_expression 显式转换为适当的大值数据类型。

于 2016-11-15T15:02:21.540 回答
2 
SELECT len(Replicate(cast('1234567890' as varchar(max)),1000))

Returns 10000
于 2016-11-15T15:03:01.033 回答
1

复制函数中的“123456”文本不是 varchar(max) 数据类型。正如 Dudu 提到的，如果表达式不是 varchar(max) 数据类型，则复制函数限制为 8000 个字符。

于 2016-11-15T15:10:26.643 回答
0

嘟嘟解释的很清楚。下面的字符串是 9,060 个字符。

 DECLARE @VarCharMax VarChar(Max)
 SET @VarCharMax = 'This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!This is a test!'
 PRINT Right(@VarCharMax,3)  -- returns st!
 PRINT Right(Left(@VarCharMax,8000),3) -- returns is 
 PRINT Right(Left(@VarCharMax,7999),3) -- returns his
 PRINT Right(Left(@VarCharMax,7998),3) -- returns Thi
 PRINT Right(Left(@VarCharMax,7997),3) -- returns !Th
 PRINT Right(Left(@VarCharMax,7996),3) -- returns t!h

如我所料，这将返回。

于 2016-11-15T15:22:55.707 回答