Reading and Writing LOBs En Bloc

Reading and writing LOBs en bloc implies that either you retrieve the value of the BLOB and CLOB columns into a byte array or a string, or you insert data from a byte array or a string.

Activities

Reading LOBs en Bloc

The JDBC API provides the methods getBytes() and getString() methods of java.sql.ResultSet. They enable you to read BLOB or CLOB columns into a byte array or a string respectively.

Syntax Syntax

Reading LOBs en Bloc using JDBC

String query = "select REFMANUAL, PICTURE from BC_CR_VEHICLE " +
	"where NAME = ?";
PreparedStatement ps = conn.prepareStatement(query);
try {
  ps.setString(1, "Golf");
  ResultSet rs = ps.executeQuery();
  try {
	while (rs.next()) {
		String refManual = rs.getString("REFMANUAL");
		byte[] image = rs.getBytes("PICTURE");
  ...
	}
  finally {
	rs.close();
  }
finally {
  ps.close();
}

End of the code.

Writing LOBs en Bloc

To insert data from a byte array or a string with JDBC, you should use setBytes() or setString() methods of java.sql.PreparedStatement.

Syntax Syntax

Writing LOBs en Bloc using JDBC

String manual = "...";
byte[] picture = ...;

String insertStmt = "insert into VEHICLE " +
	"(NAME, REFMANUAL, PICTURE) VALUES (?, ?, ?)";
PreparedStatement ps = conn.prepareStatement(insertStmt);
try {
	ps.setString(1, "Golf");
	ps.setString(2, manual);
	ps.setBytes(3, picture);
	ps.executeUpdate()
}finally{
ps.close();
}

End of the code.