node.js - Arangodb 中的交易

Question

我在 ArangoDB+nodejs 中的事务有一些问题。我需要做这样的事情:

transaction
{ 
      insertedId=insertItemOneInDB();
     insertItemTwoInDB();
}

但是当第二次插入失败时，第一次没有回滚!请帮我举个例子!

这是我的代码:

var transaction = function (collections,params,callback)
{
    try
    {

        db.transaction.submit("user_merchant_tbl",params,
            function () 
            {
                console.log("_collections:",collections);
                console.log("params:");
                console.log(params);
                console.log("---");
                console.log("+==========+");

                //
                var insertedDataId;
                var relationsArrayIds=[];
                db.document.create(collections,params.data).then(function(_insertedId)
                {   
                    insertedDataId=_insertedId;
                }
                ,function(err)
                { 
                    console.log("ERROR: Arango--insert-->err: %j", err);
                    //throw "Error: "+err;
                    return false; 
                });

                /////
                var relations=params.relations;
                for(var i=0;i<relations.length;i++)
                {
                    db.document.create(relations[i].edge,relations[i].data).then(
                    function(_id)
                    {   
                        relationsArrayIds.push(_id);
                        next(true);
                    }
                    ,function(err)
                    { 
                        console.log("ERROR: Arango--insert.edge-->err:23232 %j", err);
                        console.log("after return");
                        next(false); 
                        return false
                    });
                }

                console.log("transaction before true"); 

                function next(result)
                {
                    if(result==true)
                    {
                        console.log("transaction is ok:",result);
                        callback(insertedDataId,result);
                    }
                    else 
                    {   
                        console.log("transaction is not OK:",result);
                        callback(insertedDataId,false);
                    }
                }
            }
            );
    }
    catch(e)
    {
        console.log("catch->error in -->Arango.transaction: ",e);
    }
}

Answer 1

首先，似乎对如何编写应该执行的操作存在误解。此操作直接在数据库服务器上执行，因此您不能使用 Arango Javascript api 提供的任何功能。如果你想设计你的 Action ，它必须在 arango shell 或服务器控制台上运行(bin/arangod data --console)我查看了您的代码并假设您想要存储用户和商家之间的关系。由于 Arango 带有一个很好的图形模块，您可以遵循以下方法:

// First we define a graph, containing of 2 document collections ("users" and "merchants")        and 2 edge collections (one per relation type, in this example "contactRequested" and "boughtSomethingFrom".
// Note that in this definition the relation "boughtSomethingFrom" is only allowed from a user to a merchant. Of course this is just one way to design it, you have to do it the way it suits you the best.
var edgeDefinitions = [{
  collection: "contactRequested",
  from: ["users", "merchants"],
  to: ["users", "merchants"]
}, {
collection: "boughtSomethingFrom",
from: ["users"],
to: ["merchants"]
}];

// Now we create a graph called "user_merchant_graph" and in the callback function execute a transaction
db.graph.create("user_merchant_graph", edgeDefinitions, function(err, ret, message) {

  // Lets define the action for the transaction, again this will be executed directly on the server ......
  var action = function (params) {

// We have to require the database module ....

var db = require("internal").db;
var relationsArrayIds = [];

// now we store the user provided to the function
var insertedUserId = db["users"].insert(params.data)._id;

var relations = params.relations;
// Now we loop over through the relations object, store each merchant and it's relations to the user
Object.keys(relations).forEach(function (relation) {
  // store merchant
  var insertedMerchantId = db["merchants"].insert({merchantName : relation})._id;
  // store relation as edge from "insertedUserId" to "insertedMerchantId".
  var edgeId = db[relations[relation].relation].insert(insertedUserId, insertedMerchantId, relations[relation].additionalData)._id;
  relationsArrayIds.push(edgeId);
});
  };
  // End of action

  var options = {};
  options.params = {
data: {
  userName : "someUserName",
  userSurname : "someUserSurname"
},
relations : {
  merchantA : {relation : "contactRequested", additionalData : {data :"someData"}},
  merchantB : {relation : "boughtSomethingFrom", additionalData : {data :"someData"}},
  merchantC : {relation : "contactRequested", additionalData : {data :"someData"}}
}
  };
  // Now we call the transaction module ...  a note to the collections parameter, it has to be an object containing the keys "write" and "read" which have a list of all collections as value into which the action is writing /reading from
  // This collections object is NOT available within your action, the only thing passed as argument to your action is "options.params" !!
  db.transaction.submit({write : ["users", "merchants", "contactRequested", "boughtSomethingFrom"]}, action, options, function(err, ret, message) {
//some callback
  });

});

关于他们正在处理的交易，您可以试一试这段代码，如果您觉得。弄乱边的存储(将其更改为“var edgeId = db[relations[relation].relation].insert(relations[relation].additionalData)._id;”)你会看到你的用户和商户还没有被存储

希望对你有帮助