SQL 事务处理
我写了一个函数， 想要把删除和插入联合成一个事务， 要么全执行， 要么都不执行？
不知道 怎么写？


public boolean addBatch(int roleID, int permissionID[]) {

try {

// 先删除所有的数据, 然后再插入所有的数据
sSQL = "delete from RolesPermissions where RoleID= " + roleID;
stmt = conn.createStatement();
rs = stmt.executeQuery(sSQL);

PreparedStatement stmt = conn
.prepareStatement( "INSERT INTO RolesPermissions VALUES(?,?,?) ");

for (int i = 0; i < permissionID.length; i++) {
stmt.setInt(2, roleID);
stmt.setInt(1, permissionID[i]);
stmt.addBatch();
}
int[] counts=stmt.executeBatch();

} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return flag;

}

[解决办法]
给个例子：
***************************************

public class OrderHandler extends HttpServlet {

public void doPost(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
res.setContentType( "text/plain ");
PrintWriter out = res.getWriter();

Connection con = null;
try {
Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver ");
con = DriverManager.getConnection( "jdbc:odbc:ordersdb ", "user ", "passwd ");

// Turn on transactions
con.setAutoCommit(false);

Statement stmt = con.createStatement();
stmt.executeUpdate(
"UPDATE INVENTORY SET STOCK = (STOCK - 10) WHERE PRODUCTID = 7 ");
stmt.executeUpdate(
"UPDATE SHIPPING SET SHIPPED = (SHIPPED + 10) WHERE PRODUCTID = 7 ");

chargeCard(); // method doesn 't actually exist...

con.commit();
out.println( "Order successful! Thanks for your business! ");
}
catch (Exception e) {
// Any error is grounds for rollback
try {
con.rollback();
}
catch (SQLException ignored) { }
out.println( "Order failed. Please contact technical support. ");
}
finally {
// Clean up.
try {
if (con != null) con.close();
}
catch (SQLException ignored) { }
}
}
}