On 2016-10-08 2:36 AM, Stephen Davies wrote:
On 07/10/16 19:24, Thomas Kellerer wrote:
Stephen Davies schrieb am 07.10.2016 um 10:46:
You can store the contents of a file in a bytea using plain JDBC no
lo_import() required
String sql = "insert into images (id, image_data) values (?,?)";
Connection con = ....;
File uploaded = new File("...");
InputStream in = new FileInputStream(uploaded);
PreparedStatement pstmt = con.prepareStatement(sql);
pstmt.setInt(1, 42);
pstmt.setBinaryStream(in, (int)uploaded.length());
pstmt.executeUpdate();
This *only* works with bytea column, not with "large objects".
In production code you obviously need to close all resources and
handle errors.
I left that out for simplicity.
That looks reasonable but I need to update rather than insert and my
similar
code with sql="update part set pic=? where id=3" did not work.
That *will* work (using that myself for updates as well).
What exactly is your problem? What was the error/exception?
I tried the prepared statement approach again and this time it worked.
No idea what I did wrong last time.
However, my display code still does not work.
You need to stream the data. Working from memory here, and it's been a
long time, but it's something like
rs = conn.executeQuery("SELECT byeta_column FROM foo WHERE bar = ?");
Blob b = (Blob) rs.getObject(1);
InputStream is = b.getInputStream();
byte[1024] bytes;
while (is.read(bytes)) {
System.out.print(String(bytes));
}
Something like this, modulo using PreparedStatements and proper use of
the byte[] buffer.
Cheers and thanks,
Stephen
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