PostgreSQL \lo_import and how to get the resulting OID into an UPDATE command?

As your file resides on your local machine and you want to import the blob to a remote server, you have two options:

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) Use the psql meta-command like you have it.

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';

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

• \\ 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.

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