从csv文件加载数据时asynchronous节点/mongoose问题

我是Node新手，一般的asynchronous编程，我无法绕开这个问题。

我使用Mongoose将注册选民的数据导入到MongoDB中。 你可以想象，许多选民住在同一条街上。 在我的导入过程中，我检查一下街是否已经存在。 如果没有，我需要创build一个新的街道文件。 如果是这样，我只是想创build一个地址子文档。

我遇到的问题是我不知道如何处理find（）Mongoose命令是asynchronous的。 所以在我的代码中发生的事情是，当CSV行被parsing时，所有的find命令都被排队，但是不会立即执行。 我的程序读取一行，例如看到一个“Choctaw St”的logging，并排队find（）命令以查看它是否存在。 但下一行也可能是Choctaw St，另一个find（）命令将排队。 在Mongo中创build文档发生在find（）命令的callback中，在执行完所有的find命令之后，find（）命令可能无法运行。 因此，当发现一个接一个地运行时，程序将尝试多次创build文档

这里是我的代码片段：

Street.findOne( { campaign_id: user_id, street_name: streetData.street_name, city: streetData.city }, function(err, foundStreet) { if(err) { console.log(err) } if(foundStreet) { console.log('Found street: ' + foundStreet.street_name + '. Not adding!!!') //Code for address insertion will go here. } else { console.log(streetData.street_name + ' not found. Adding now.') let newStreet = new Street({ campaign_id: user_id, street_name: streetData.street_name, city: streetData.city }) newStreet.save((err, streetDoc) => { if(err) { console.log('Error creating street: ' + newStreet.street_name) } if(streetDoc) { console.log('Street created: ' + streetDoc.street_name) } }) } }) 

下面是我的程序的输出，突出了我的问题。 我提前道歉的长度。 正如你所看到的，当试图创build重复的街道文档时，会引发错误。

任何帮助将不胜感激。 我不敢相信我的情况是那么特别，但是我一直被困在这个问题上3天，还没有find解决办法。

 Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"DEERPATH RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"HUNTINGTON PL","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"SULLIVAN DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"QUAIL CREEK DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"N CHEROKEE AVE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"STEEPLECHASE CT","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"LOCKWYNN TRCE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"SHOREWOOD DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"TWIN OAKS LN","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"BAKER TRCE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"N ENGLEWOOD AVE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"PLANTATION RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"OVERLOOK DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"ADRIAN RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"DEERPATH RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"N CHEROKEE AVE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"EMERALD LAKE DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"RADCLIFF RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"BAKER TRCE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"GABRIEL CT","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"RENDALE RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"MILL RIDGE RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"CHOCTAW ST","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"RICHMOND RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"BRIARCLIFF RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"GIRARD AVE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"HEATHERBROOK PL","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"CARDINAL CT","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"GARDENIA DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"HOUSTON ST","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"BUENA VISTA DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"MOCKINGBIRD LN","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"LASALLE DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"WHIFFLETREE WAY","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"LOBLOLLY LN","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"DEERPATH RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"FOXRIDGE RD","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"AZURE DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"SHADYBROOK LN","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"FAIRFIELD DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"AZURE DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"QUAIL CREEK DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"SUMMERRAIN TER","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"FAIRFIELD DR","city":"DOTHAN","addresses":[]} DEERPATH RD not found. Adding now. STEEPLECHASE CT not found. Adding now. QUAIL CREEK DR not found. Adding now. Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"HUNTINGTON PL","city":"DOTHAN","addresses":[]} N CHEROKEE AVE not found. Adding now. Street created: DEERPATH RD Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"N PONTIAC AVE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"N CHEROKEE AVE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"IMPALA DR","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"BAKER TRCE","city":"DOTHAN","addresses":[]} Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"AZURE DR","city":"DOTHAN","addresses":[]} Street created: STEEPLECHASE CT BAKER TRCE not found. Adding now. DEERPATH RD not found. Adding now. GABRIEL CT not found. Adding now. BRIARCLIFF RD not found. Adding now. HOUSTON ST not found. Adding now. LOBLOLLY LN not found. Adding now. FAIRFIELD DR not found. Adding now. TWIN OAKS LN not found. Adding now. ADRIAN RD not found. Adding now. BAKER TRCE not found. Adding now. RICHMOND RD not found. Adding now. GARDENIA DR not found. Adding now. WHIFFLETREE WAY not found. Adding now. SHADYBROOK LN not found. Adding now. FAIRFIELD DR not found. Adding now. SULLIVAN DR not found. Adding now. SHOREWOOD DR not found. Adding now. OVERLOOK DR not found. Adding now. RADCLIFF RD not found. Adding now. N ENGLEWOOD AVE not found. Adding now. N CHEROKEE AVE not found. Adding now. RENDALE RD not found. Adding now. GIRARD AVE not found. Adding now. BUENA VISTA DR not found. Adding now. DEERPATH RD not found. Adding now. AZURE DR not found. Adding now. Street created: N CHEROKEE AVE Adding streetData: {"campaign_id":"59dcde03ea6bdc44cb51b655","street_name":"HAYES DR","city":"DOTHAN","addresses":[]} Street created: QUAIL CREEK DR N PONTIAC AVE not found. Adding now. AZURE DR not found. Adding now. CHOCTAW ST not found. Adding now. CARDINAL CT not found. Adding now. LASALLE DR not found. Adding now. AZURE DR not found. Adding now. SUMMERRAIN TER not found. Adding now. HUNTINGTON PL not found. Adding now. BAKER TRCE not found. Adding now. Found street: N CHEROKEE AVE. Not adding!!! HUNTINGTON PL not found. Adding now. LOCKWYNN TRCE not found. Adding now. PLANTATION RD not found. Adding now. EMERALD LAKE DR not found. Adding now. MILL RIDGE RD not found. Adding now. HEATHERBROOK PL not found. Adding now. MOCKINGBIRD LN not found. Adding now. FOXRIDGE RD not found. Adding now. QUAIL CREEK DR not found. Adding now. IMPALA DR not found. Adding now. Street created: HOUSTON ST Street created: BAKER TRCE Street created: FAIRFIELD DR Street created: N ENGLEWOOD AVE Error creating street: DEERPATH RD Street created: GARDENIA DR Street created: SHOREWOOD DR Street created: RENDALE RD Error creating street: DEERPATH RD Error creating street: FAIRFIELD DR Street created: BRIARCLIFF RD Street created: ADRIAN RD Street created: SHADYBROOK LN Street created: RADCLIFF RD Street created: BUENA VISTA DR Street created: GABRIEL CT Street created: TWIN OAKS LN Street created: WHIFFLETREE WAY Street created: OVERLOOK DR Street created: GIRARD AVE Street created: LOBLOLLY LN Street created: RICHMOND RD Street created: SULLIVAN DR Street created: AZURE DR Error creating street: BAKER TRCE Error creating street: N CHEROKEE AVE HAYES DR not found. Adding now. Street created: CHOCTAW ST Error creating street: AZURE DR Street created: N PONTIAC AVE Street created: HUNTINGTON PL Error creating street: AZURE DR Street created: CARDINAL CT Street created: MILL RIDGE RD Error creating street: BAKER TRCE Street created: LASALLE DR Street created: EMERALD LAKE DR Error creating street: QUAIL CREEK DR Street created: IMPALA DR Street created: SUMMERRAIN TER Street created: PLANTATION RD Street created: LOCKWYNN TRCE Street created: MOCKINGBIRD LN Street created: FOXRIDGE RD Street created: HEATHERBROOK PL Error creating street: HUNTINGTON PL Street created: HAYES DR