JDBC Driver for SQL/MX Programmer's Reference

// read Blob data using the InputStream
byte[] myBlobData = new byte[length];
is.read(myBlobData, offset, length);
Updating BLOB Data
You can update BLOB data by using the methods in the Blob interface or by using the
updateClob method of the ResultSet interface. The JDBC/MX driver makes changes to
the BLOB data directly. Hence, the JDBC/MX driver returns false to the
locatorsUpdateCopy method of the DatabaseMetaData interface. Applications do
not need to issue a separate update statement to update the BLOB data.
Update BLOB data in the following ways.
Updating Blob Objects by using the updateBlob Method●
Replacing Blob Objects●
Updating Blob Objects by Using the
updateBlob Method
Unlike some LOB support implementations, the JDBC/MX driver updates the BLOB data
directly in the database. So, when the Blob object is the same in the updateBlob method as
the object obtained using getBlob, the updateRow method of the ResultSet interface
does nothing with the Blob object.
When the Blob objects differ, the Blob object in the updateBlob method behaves as if the
setBlob method was issued. See Inserting a Blob Object with the setBlob Method.
Replacing Blob Objects
You can replace Blob objects in the following ways:
Use the EMPTY_BLOB() function to replace the Blob object with the empty Blob
object.
●
Replace an existing Blob object in a row by inserting the Blob with new data as
described under Inserting a BLOB Column Using the Blob Interface.
●
Use the setBinaryStream() method to of the PreparedStatement interface
replace the existing Blob object with new BLOB data.
●
Use the setBlob or updateBlob methods to replace the existing BLOB objects as
explained earlier under Inserting a Blob Object with the setBlob Method and Updating
Blob Objects with the UpdateBlob Method.
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