SQL Query to store text data in a Varbinary(max)

问题

Is there a way to make a varbinary accept text data in SQL Server?

Here is my situation. I have a fairly large amount of XML that I plan on storing in a "zipped" format. (This means a Varbinary.)

However, when I am debugging, I want to be able to flip a configuration switch and store in plain text so I can troubleshoot from the database (ie no client app to un-zip needed).

Is it possible to insert normal text in to a varbinary(max)?

回答1:

Is it possible to insert normal text in to a varbinary(max)?

Yes, just be sure of what you are storing so you know how to get it back out. This may shed some light on that:

-- setup test table
declare @test table (
    data varbinary(max) not null,
    datatype varchar(10) not null
)

-- insert varchar
insert into @test (data, datatype) select cast('asdf' as varbinary(max)), 'varchar'
-- insert nvarchar
insert into @test (data, datatype) select cast(N'asdf' as varbinary(max)), 'nvarchar'

-- see the results
select data, datatype from @test
select cast(data as varchar(max)) as data_to_varchar, datatype from @test
select cast(data as nvarchar(max)) as data_to_nvarchar, datatype from @test

UPDATE: All of this assumes, of course, that you don't want to utilize the expressive power of SQL Server's native XML datatype. The XML datatype also seems to store its contents fairly efficiently. In my database I regularly see that it's as little as half the size of an equal string of varchar, according to datalength(). This may not be all that scientific, and of course, YMMV.

回答2:

You can use this answer to convert your string to a byte array, and insert the result into a varbinary(max) column. The idea is to use BinaryFormatter with a MemoryStream to serialize the string, harvest the resulting byte array from the memory stream, and write it into a varbinary(max) column.

来源：https://stackoverflow.com/questions/9067470/sql-query-to-store-text-data-in-a-varbinarymax

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.net

sql-server

tsql

text

varbinary