PostgreSQL \lo_import以及如何将生成的OID转换为UPDATE命令? [英] PostgreSQL \lo_import and how to get the resulting OID into an UPDATE command?
问题描述
我正在使用Postgres 9.0,并且有一个应用程序需要在其中将图像插入到远程 c $ c服务器中。所以我用:
I'm working with Postgres 9.0, and I have an application where I need to insert images into the remote server
. So I use:
"C:\Program Files\PostgreSQL\9.0\bin\psql.exe" -h 192.168.1.12 -p 5432 -d myDB -U my_admin -c "\lo_import 'C://im/zzz4.jpg'";
其中
192.168.1.12
是服务器系统的IP地址
192.168.1.12
is the IP address of the server system
5432
是服务器系统的IP地址。端口号
5432
is the Port number
myDB
是服务器数据库名称
my_admin
是用户名
\lo_import'C:// im / zzz4 .jpg'
是触发的查询。
在将图像插入数据库后,我需要像这样更新表中的一行:
After the image has been inserted into the database I need to update a row in a table like this:
UPDATE species
SET speciesimages=17755; -- OID from previous command.. how to get the OID ??
WHERE species='ACCOAA';
所以我的问题是:如何获得 OID $ c在psql中
$ lo_import
之后返回$ c>?
So my question is: how do I get the OID
returned after the \lo_import
in psql?
我尝试运行 \ grelo_import'C://im/zzz4.jpg'
在Postgres中,但出现错误:
I tried running \lo_import 'C://im/zzz4.jpg'
in Postgres but I get an error:
ERROR: syntax error at or near ""\lo_import 'C://im/zzz4.jpg'""
LINE 1: "\lo_import 'C://im/zzz4.jpg'"
我也尝试了此操作:
update species
set speciesimages=\lo_import 'C://im/zzz4.jpg'
where species='ACAAC04';
但我收到此错误:
ERROR: syntax error at or near "\"
LINE 2: set speciesimages=\lo_import 'C://im/zzz4.jpg'
^
推荐答案
文件位于本地计算机上,并且您想将blob导入到远程服务器上,您有两个选择:
As your file resides on your local machine and you want to import the blob to a remote server, you have two options:
1)将文件传输到服务器并使用服务器端功能:
1) Transfer the file to the server and use the server-side function:
UPDATE species
SET speciesimages = lo_import('/path/to/server-local/file/zzz4.jpg')
WHERE species = 'ACAAC04';
2)使用 psql元命令,如您所愿。
2) Use the psql meta-command like you have it.
但是您不能将psql元命令与SQL命令混合使用,这是不可能的。
在:LASTOID
在同一psql会话中 \lo_import
元命令之后立即启动的> UPDATE 命令:
But you cannot mix psql meta commands with SQL-commands, that's impossible.
Use the psql variable :LASTOID
in an UPDATE
command that you launch immediately after the \lo_import
meta command in the same psql session:
UPDATE species
SET speciesimages = :LASTOID
WHERE species = 'ACAAC04';
编写脚本(在Linux中工作,我对Windows Shell脚本不熟悉):
To script that (works in Linux, I am not familiar with Windows shell scripting):
echo "\lo_import '/path/to/my/file/zzz4.jpg' \\\\ UPDATE species SET speciesimages = :LASTOID WHERE species = 'ACAAC04';" | \
psql -h 192.168.1.12 -p 5432 -d myDB -U my_admin
-
\\
是分隔符元命令。您需要在\
加倍,因为外壳解释了一层。 -
\
换行符只是Linux shell中的行延续。 \\
is the separator meta-command. You need to double the\
, in a""
string, because the shell interprets one layer.\
before the newline is just the line continuation in Linux shells.
备用语法(再次在Linux上测试):
Alternative syntax (tested on Linux again):
psql -h 192.168.1.12 -p 5432 -d myDB -U my_admin << EOF
\lo_import '/path/to/my/file/zzz4.jpg'
UPDATE species
SET speciesimages = :LASTOID
WHERE species = 'ACAAC04';
EOF
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