| 发表于：2007-12-06 22:59:591楼 得分:0 |
给你一个例子看看
samples\java\jdbc\dtlob.java
import java.io.*;
import java.lang.*;
import java.util.*;
import java.sql.*;
class dtlob
{
public static void main（string argv[])
{
try
{
db db = new db（argv);
system.out.println（);
system.out.println（"this sample shows how to use lob data type.");
// connect to the 'sample' database
db.connect（);
blobfileuse（db.con);
// disconnect from the 'sample' database
db.disconnect（);
}
catch （exception e)
{
jdbcexception jdbcexc = new jdbcexception（e);
jdbcexc.handle（);
}
} // main
static void blobfileuse（connection con)
{
try
{
system.out.println（);
system.out.println（
"----------------------------------------------------------\n" +
"use the sql statements:\n" +
" select\n" +
" insert\n" +
" delete\n" +
"to show how to use binary large object （blob) files.");
string osname = system.getproperty（"os.name");
string photoformat;
string filename;
string empno;
if （osname.equals（"windows nt"))
{
photoformat = "bitmap";
filename = "photo.bmp";
}
else
{
// unix
photoformat = "gif";
filename = "photo.gif";
}
// ---------- read blob data from file -------------------
system.out.println（);
system.out.println（
" ---------------------------------------------------\n" +
" read blob data from the file '" + filename + "':");
system.out.println（);
system.out.println（
" prepare the statement:\n" +
" select picture\n" +
" from emp_photo\n" +
" where photo_format = ? and empno = ?");
preparedstatement pstmt = con.preparestatement（
"select picture " +
" from emp_photo " +
" where photo_format = ? and empno = ?");
system.out.println（);
system.out.println（
" ＥＸＥＣute the prepared statement using:\n" +
" photo_format = 'bitmap'\n" +
" empno = '000130'");
empno = "000130";
pstmt.setstring（1, photoformat);
pstmt.setstring（2, empno);
resultset rs = pstmt.ＥＸＥＣutequery（);
rs.next（);
blob blob = rs.getblob（1);
rs.close（);
pstmt.close（);
system.out.println（);
system.out.println（" read from blob file successfully!");
// -------------- write blob data into file -----------------
system.out.println（);
system.out.println（
" ---------------------------------------------------\n" +
" insert blob file " + filename + " into the db:");
system.out.println（);
system.out.println（
" prepare the statement:\n" +
" insert into emp_photo（photo_format, empno, picture)\n" +
" values （?, ?, ?)");
preparedstatement pstmt2 = con.preparestatement（
"insert into emp_photo （photo_format, empno, picture) " +
" values （?, ?, ?)");
system.out.println（);
system.out.println（
" ＥＸＥＣute the prepared statement using:\n" +
" photo_format = 'bitmap'\n" +
" empno = '000137'\n" +
" and the blob object that we get from reading the\n" +
" file 'photo.*' eariler.");
empno = "000137";
pstmt2.setstring（1, photoformat);
pstmt2.setstring（2, empno);
pstmt2.setblob（3, blob);
pstmt2.ＥＸＥＣuteupdate（);
pstmt2.close（);
system.out.println（);
system.out.println（" insert blob file to db successfully!");
// ------------ delete new record from the database ---------
system.out.println（);
system.out.println（
" ---------------------------------------------------\n" +
" delete the new record from the database:");
system.out.println（);
system.out.println（
" prepare the statement:\n" +
" delete from emp_photo where empno = ?");
preparedstatement pstmt3 = con.preparestatement（
"delete from emp_photo where empno = ? ");
system.out.println（);
system.out.println（
" ＥＸＥＣute the prepared statement using:\n" +
" empno = '000137'");
pstmt3.setstring（1, empno);
pstmt3.ＥＸＥＣuteupdate（);
pstmt3.close（);
system.out.println（);
system.out.println（" delete the new record from db successfully!");
}
catch （exception e)
{
jdbcexception jdbcexc = new jdbcexception（e);
jdbcexc.handle（);
}
} // blobfileuse
} // dtlob class | | |
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