JDBC Type 2 Driver Programmer's Reference for SQL/MX Release 3.2.1 (H06.26+, J06.15+)

Then, you must obtain the handle to the empty BLOB column by selecting the BLOB column for
update.
The following code illustrates how to obtain the handle to an empty BLOB column:
Blob myBlob = null;
Statement s = conn.createStatement();
ResultSet rs = s.executeQuery("Select myBlobColumn
from myTable where …For update");
if (rs.next())
myBlob = rs.getBlob(1);
You can now write data to the BLOB column. See “Writing Binary Data to a BLOB Column”
(page 50).
Writing Binary Data to a BLOB Column
You can write data to the BLOB column by using Blob interfaces. The following code illustrates
using the setBinaryStream method of the Blob interface to write BLOB data.
Blob myBlob = null
// Stream begins at position 1
long pos = 1;
// Example string containing binary data
String s = "BINARY_DATA";
for (int i=0; i<5000; i++) s = s + "DATA";
// Obtain the output stream to write Blob data
OutputStream os = myBlob.setBinaryStream(pos);
// write Blob data using OutputStream
byte[] myBlobData = s.getBytes();
os.write(myBlobData);
The JDBC/MX driver splits the output stream into chunks and stores the chunks in the LOB table.
Inserting a BLOB Column by Using the PreparedStatement Interface
You can also insert a BLOB column that has binary data from a FileInputSteam. You must use
PreparedStatement interface to insert the BLOB column.
FileInputStream inputBinary = new FileInputStream(myBlobTestFile);
int blobLen = inputBinary.available();
PreparedStatement ps = conn.prepareStatement("insert
into myTable (myBlobColumn) values (?)");
ps.setBinaryStream(1, inputBinary, blobLen);
ps.executeUpdate();
The JDBC/MX driver reads the data from FileInputSteam and writes the data to the LOB table.
The JDBC/MX driver substitutes the next-available data locator for the parameter of the BLOB
column in the table.
Inserting a Blob Object by Using the setBlob Method
Your JDBC application cannot directly instantiate a Blob object. To perform an equivalent operation:
1. Obtain a Blob object by using the getClob method of the ResultSet interface.
2. Insert the Blob object into another row by using the setBlob method of the
PreparedStatement interface.
In this situation, the JDBC/MX driver generates a new data locator and copies the contents of the
source Blob into the new Blob object when the application issues the setBlob method of the
PreparedStatement interface.
50 Working with BLOB and CLOB Data