JDBC Type 4 Driver 2.0 Programmer's Reference (SQL/MX 2.x)

Note:

The EMPTY_CLOB() function is an HP NonStop specific function and might not work

on other databases.

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Do not use the EMPTY_CLOB() function when using the PreparedStatement

interface.

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The Type 4 driver scans the SQL string for the EMPTY_CLOB() function and substitutes the

next-available data locator.

Then, obtain the handle to the empty CLOB column by selecting the CLOB column for update. The

following code illustrates how to obtain the handle to an empty CLOB column:

Clob myClob = null;

Statement s = conn.createStatement();

ResultSet rs = s.executeQuery("Select myClobColumn

from myTable where ….for update");

if (rs.next())

myCLOB = rs.getClob(1);

You can now write data to the CLOB column. See Writing ASCII or Unicode Data to a CLOB Column.

Note: Limitation: Do not rename the CLOB column in the select query.

Writing ASCII or MBCS Data to a CLOB Column

You can write ASCII or MBCS data to a CLOB column.

Note: Multibyte Character Set (MBCS) data and ASCII data are handled the same way.

ASCII Data

To write ASCII or MBCS data to the CLOB column, use the Clob interface. The following code

illustrates using the setAsciiStream method of the Clob interface to write CLOB data.

// stream begins at position: 1

long pos = 1;

//String containing the ASCII data

String s ;

// Obtain the output stream to write Clob data

OutputStream os = myClob.setAsciiStream(pos);

// write Clob data using OutputStream

byte[] myClobData = s.getBytes();

os.write(myClobData);

The Type 4 driver splits the output stream into chunks and stores the chunks in the LOB table.