Re: import_bytea function - Mailing list pgsql-general

From Thomas Kellerer
Subject Re: import_bytea function
Date
Msg-id nt7lnp$l9m$1@blaine.gmane.org
Whole thread Raw
In response to import_bytea function  (Stephen Davies <sdavies@sdc.com.au>)
Responses Re: import_bytea function  (Stephen Davies <sdavies@sdc.com.au>)
List pgsql-general
Stephen Davies schrieb am 07.10.2016 um 09:12:
> I am trying to use the import_bytea function described in various list posts (PG version 9.3.14) in a jsp.
>
> I get an error saying that only the super user can use server-side lo_import().
>
> If I change the Java connection to use user postgres, the function works but I would prefer not to do this.
>
> Is there a better way to update a bytea column from an uploaded file (in this case a small jpeg)?

Since you mention JSP, I assume you are using JDBC.

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.

Thomas



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