发信人: gts()
整理人: dongbao(2002-04-19 16:38:48), 站内信件
|
Q. How do I store/retrieve text and image data in SQL Server?
A. To store/retrieve this sort of data within TSQL scripts you have to
use the WRITETEXT and READTEXT commands rather than standard INSERT/S
ELECT statements. These are documented, with examples, in the books-o
nline but are basically a real pain to use. There are more manageable
commands available from within the relevant programming languages - e
.g. RDO and ADO from VB/C can use GetChunk and AppendChunk commands -
but you still have to manage the image/text chunks/blocks of data at a
time. About the only upside of storing this sort of data within SQL
Server is that it can be kept transactionally consistent with the othe
r data.
For native ODBC access use the SQLPutData and SQLGetData commands.
If you just want to insert/retrieve an entire image/text then look at
the TEXTCOPY program (textcopy /? for parameters) in the <sql>\BINN di
rectory. It is a command-line program along the lines of BCP.
There is a very useful (free) dll available from http://www.chriscrawf
ord.com/DBImage (courtesy of Chris Crawford). It has three functions:
GetImage Used for getting an image from the database
StoreImage Used to send an image to the database
GetWebImage Used to send a DB image to a browser
If transactional consistency doesn't matter, or can be achieved progra
mmatically, then it is easier to store the data outside the database a
s an ordinary file. Within the database just hold a UNC pointer to wh
ere the file is held. This usually makes it much easier to display/ed
it the data as the name can simply be passed to whatever tool is doing
the manipulation.
--
※ 来源:．月光程序代码网 http://www.moon-soft.com．[FROM: 202.106.21.78]
|
|