与执行单条语句类似，提交或回滚事务也可能触发警告。为了能够处理这些警告，需要检查 Session.commit(); 或 Session.rollback(); 返回的结果对象。

以下示例展示了这一点。该示例假设测试模式存在，而集合 my_collection 不存在。

var mysqlx = require('mysqlx');

// Connect to server
var mySession = mysqlx.getSession( {
        host: 'localhost', port: 33060,
        user: 'user', password: 'password' } );

// Get the Schema test
var myDb = mySession.getSchema('test');

// Create a new collection
var myColl = myDb.createCollection('my_collection');

// Start a transaction
mySession.startTransaction();
try
{
    myColl.add({'name': 'Rohit', 'age': 18, 'height': 1.76}).execute();
    myColl.add({'name': 'Misaki', 'age': 24, 'height': 1.65}).execute();
    myColl.add({'name': 'Leon', 'age': 39, 'height': 1.9}).execute();

    // Commit the transaction if everything went well
    var reply = mySession.commit();

    // handle warnings
    if (reply.warningCount){
      var warnings = reply.getWarnings();
      for (index in warnings){
        var warning = warnings[index];
        print ('Type ['+ warning.level + '] (Code ' + warning.code + '): ' + warning.message + '\n');
      }
    }

    print ('Data inserted successfully.');
}
catch(err)
{
    // Rollback the transaction in case of an error
    reply = mySession.rollback();

    // handle warnings
    if (reply.warningCount){
      var warnings = reply.getWarnings();
      for (index in warnings){
        var warning = warnings[index];
        print ('Type ['+ warning.level + '] (Code ' + warning.code + '): ' + warning.message + '\n');
      }
    }

    // Printing the error message
    print ('Data could not be inserted: ' + err.message);
}

默认情况下，所有警告都从服务器发送到客户端。如果已知某个操作会生成许多警告，并且这些警告对应用程序没有价值，则可以禁止发送警告。这有助于节省带宽。session.setFetchWarnings() 控制是在服务器上丢弃警告还是将警告发送到客户端。session.getFetchWarnings() 用于了解当前的活动设置。

var mysqlx = require('mysqlx');

function process_warnings(result){
  if (result.getWarningCount()){
    var warnings = result.getWarnings();
    for (index in warnings){
      var warning = warnings[index];
      print ('Type ['+ warning.level + '] (Code ' + warning.code + '): ' + warning.message + '\n');
    }
  }
  else{
    print ("No warnings were returned.\n");
  }
}

// Connect to server
var mySession = mysqlx.getSession( {
  host: 'localhost', port: 33060,
  user: 'user', password: 'password' } );

// Disables warning generation
mySession.setFetchWarnings(false);
var result = mySession.sql('drop schema if exists unexisting').execute();
process_warnings(result);

// Enables warning generation
mySession.setFetchWarnings(true);
var result = mySession.sql('drop schema if exists unexisting').execute();
process_warnings(result);