Jaybird 2.1 JDBC driver Java Programmer's Manual - Firebird

Batch Updates
Batch updates are intended to group multiple update operations to be submitted to
a database server to be processed at once. Firebird does not provide support for
such functionality, but Jaybird emulates it by issuing separate update commands.
Batch Updates with java.sql.Statement interface
The Statement interface defines three methods for batch updates: addBatch,
executeBatch and clearBatch. It is allowed to add arbitrary
INSERT/UPDATE/DELETE or DDL statement to the batch group. Adding a
statement that returns result set is an error.
Statement stmt = connection.createStatement();
stmt.addBatch("UPDATE products " +
"SET amount = amount – 1 WHERE id = 1");
stmt.addBatch("INSERT INTO orders(id, amount) VALUES(1,
1)");
int[]updateCounts = stmt.executeBatch();
Illustration 4.15.: Example of batch updates using Statement object
The JDBC specification recommends to turn the auto-commit mode off to
guarantee standard behavior for all databases. The specification explicitly states
that behavior in auto-commit case is implementation defined. Jaybird executes a
batch in a single transaction, i.e. the “all-or-nothing” principle. A new transaction
is started before the batch execution and is committed if there were no exception
during batch execution, or is rolled back if at least one batch command generated
an error.
The Statement.executeBatch method submits the job to the database server. In
case of successful execution of the complete batch, it returns an array of integers
containing update counts for each of the commands. Possible values are:
• 0 or positive value – an update count for the corresponding update/DDL
statement.
• Statement.SUCCESS_NO_INFO – driver does not have any information about
the update count, but it knows that statement was executed successfully.
The Statement.executeBatch method closes the current result set if one is open.
After successful execution the batch is cleared. Calling execute, executeUpdate
and executeQuery before the batch is executed does not have any effect on the
currently added batch statements.
If at least one statement from the batch fails, a
java.sql.BatchUpdateException is thrown. Jaybird will stop executing
statements from batch after the first error. In auto-commit mode it will also
rollback the transaction. An application can obtain update counts for the already
executed statements using getUpdateCounts method of the
BatchUpdateException class. The returned array will always contain fewer
entries than there were statements in the batch.
Batch Updates with java.sql.PreparedStatement and java.sql.CallableStatement
Chapter 4. Executing statements 50