NodeRed函数节点崩溃 - [红色]未捕获异常：

Question

我很难理解为什么我的Node-Red Flow不断崩溃[RED] Uncaught Exception。它几乎看起来像是功能节点崩溃了，并且我的函数节点内的代码从来没有机会去捕捉它。

我有一个非常简单的Node-Red流程，它执行一个IBMDB node.js库来将数据插入到我的数据库中。为了使用IBMDB库，我必须将包添加到我的packages.json文件中的包列表中。我还必须在Bluemix-setings.js文件中设置全局上下文变量。我将这个全局上下文变量IBMDB命名为与require语句等效的变量。一旦完成，我可以使用函数节点内的库。

**以下是我正在使用的Node.js IBMDB库。 https://github.com/ibmdb/node-ibm_db

**这里是流

**下面是函数内的代码。

try { 
context.global.ibmdb.open("DATABASE=database;HOSTNAME=hostname;PORT=port;PROTOCOL=TCPIP;UID=username;PWD=password;", function (err,conn) { 

    conn.beginTransaction(function (err) { 
    if (err) { 
     //could not begin a transaction for some reason. 
     console.log(err); 
     return conn.closeSync(); 
    } 

    for (i = 0; i < msg.payload.Readings.length; i++) 
    { 
     var result = conn.querySync("INSERT INTO db2.table (" + 
            "I_ID," + 
            "D_ID," + 
            "field1," + 
            "field2," + 
            "field3," + 
            "field4," + 
            "field5," + 
            "field6," + 
            "field7," + 
            "field8," + 
            "field9," + 
            "field10)" + 
            "values (" + 
            "1A," + 
            "'"+ msg.payload.field1 + "',"+ 
            "'" + JSON.stringify(msg.payload.Readings[i].field2) + "'," + 
            msg.payload.Readings[i].field3 + ","+ 
            msg.payload.Readings[i].field4 + ","+ 
            msg.payload.Readings[i].field5 + ","+ 
            msg.payload.Readings[i].field6 + ","+ 
            msg.payload.Readings[i].field7 + ","+ 
            msg.payload.Readings[i].field8 + ","+ 
            msg.payload.Readings[i].field9 + ","+ 
            msg.payload.Readings[i].field10 + ","+ 
            "'2016-05-31 22:28:51.000000'" + 
            ");"); 
    } 

    conn.commitTransaction(function (err) { 
     if (err) { 
     //error during commit 
     console.log("****ERROR: " + err); 
     node.error("**** ERROR: ", err); 
     //return conn.closeSync(); 
     } 

     //Close the connection 
     conn.closeSync(); 
    }); 
    }); 
}); 
} catch (e) { 
    node.error("**** ERROR: ", err); 
} 

当我跑这与有效的SQL语句，所有的数据类型正确发送，我没有得到任何错误。一切正常！

***问题：当我做了一些测试来强制SQL错误时，Node-Red实例崩溃。我通过发送一个有效的SQL语句来强制该错误，但其中一个字段中的数据元素是一个非数字值，其中表定义只期望数字。我在错误日志（控制台输出）中看到两行..

• 显示的错误SQL错误消息正是我期望在我的应用程序中捕获的内容。相反，应用程序只是崩溃。

[red] Uncaught Exception: Error: [IBM][CLI Driver][DB2/LINUXX8664] SQL0103N The numeric literal "1A" is not valid. SQLSTATE=42604

上究竟发生什么事，将不胜感激任何了解。我想知道如果我把这个代码放在一个自定义的内置节点中，我能够发现错误。这可能是使用函数节点作为我的代码包装的限制。 ???? *

Answer 1

尝试在它自己的try/catch块中包装conn.querySync调用。当前块超出范围，因为该调用发生在另一个函数（传入beginTransaction的函数）中。

例如

try { 
context.global.ibmdb.open("DATABASE=database;HOSTNAME=hostname;PORT=port;PROTOCOL=TCPIP;UID=username;PWD=password;", function (err,conn) { 

    conn.beginTransaction(function (err) { 
    if (err) { 
     //could not begin a transaction for some reason. 
     console.log(err); 
     return conn.closeSync(); 
    } 

    for (i = 0; i < msg.payload.Readings.length; i++) 
    { 
     try { 
     var result = conn.querySync("INSERT INTO db2.table (" + 
            "I_ID," + 
            "D_ID," + 
            "field1," + 
            "field2," + 
            "field3," + 
            "field4," + 
            "field5," + 
            "field6," + 
            "field7," + 
            "field8," + 
            "field9," + 
            "field10)" + 
            "values (" + 
            "1A," + 
            "'"+ msg.payload.field1 + "',"+ 
            "'" + JSON.stringify(msg.payload.Readings[i].field2) + "'," + 
            msg.payload.Readings[i].field3 + ","+ 
            msg.payload.Readings[i].field4 + ","+ 
            msg.payload.Readings[i].field5 + ","+ 
            msg.payload.Readings[i].field6 + ","+ 
            msg.payload.Readings[i].field7 + ","+ 
            msg.payload.Readings[i].field8 + ","+ 
            msg.payload.Readings[i].field9 + ","+ 
            msg.payload.Readings[i].field10 + ","+ 
            "'2016-05-31 22:28:51.000000'" + 
            ");"); 
     } catch (excp) { 
     //do stuff 
     } 
    } 

    conn.commitTransaction(function (err) { 
     if (err) { 
     //error during commit 
     console.log("****ERROR: " + err); 
     node.error("**** ERROR: ", err); 
     //return conn.closeSync(); 
     } 

     //Close the connection 
     conn.closeSync(); 
    }); 
    }); 
}); 
} catch (e) { 
    node.error("**** ERROR: ", err); 
}