node.js - 如何在NodeJs中的sequelizer中执行异步查询

Question

你好，我尝试了以下代码，但我的代码无法正常工作

tags.forEach(function(value) {
    var where1 = {};
    var attr1 = ['id'];
    attr1 = ['id'];
    where1['name'] = value;
    tagData['name'] = value;
    tagModel.getTag(where1, attr1, function(code2,result2){
        if(result2.length!=0) {
            var quick_start_tagData={'quick_start_id' : result1['id'], 'tag_id' :result2[0]['id']}
            quick_start_tagModel.saveData(quick_start_tagData, function(code2,result2){
            });
            console.log(quick_start_tagData); 
         } else {
              tagModel.saveData(tagData, function(code2,result2) {});
           }
     });
});

问题是当我将该数据的值检查到表中时，for循环迭代数据数量，如果表具有相同的值，则获取其id并插入，如果不是则添加新记录并获取其id并插入另一个表

但首先 select 查询始终执行，然后 insert 查询在循环中执行

如何解决这个问题

像这样查询执行

执行(默认):

SELECT id FROM pxl_tag AS pxl_tag WHERE pxl_tag.name = 'a1';

SELECT id FROM pxl_tag AS pxl_tag WHERE pxl_tag.name = 'a2';

SELECT id FROM pxl_tag AS pxl_tag WHERE pxl_tag.name = 'a3';

INSERT INTO pxl_tag (id,name,created_at,updated_at) VALUES (DEFAULT,'a3','2018-05-04 04:35:32','2018-05-04 04:35:32');

INSERT INTO pxl_tag (id,name,created_at,updated_at) VALUES (DEFAULT,'a3','2018-05-04 04:35:32','2018-05-04 04:35:32');

INSERT INTO pxl_tag (id,name,created_at,updated_at) VALUES (DEFAULT,'a3','2018-05-04 04:35:32','2018-05-04 04:35:32');

但我想先一步一步选择并插入

Answer 1

您可以使用each方法来自 async图书馆。例如:

更新

async.each(tags, function(value, cb) {
  var where1 = {};
  var attr1 = ['id'];
  attr1 = ['id'];
  where1['name'] = value;
  tagData['name'] = value;
  tagModel.getTag(where1, attr1, function(code2, result2) {
    if (result2.length != 0) {
      var quick_start_tagData = {
        'quick_start_id': result1['id'],
        'tag_id': result2[0]['id']
      }
      quick_start_tagModel.saveData(quick_start_tagData, function(code2, result2) {
        cb();
      });
      console.log(quick_start_tagData);
    } else {
      tagModel.saveData(tagData, function(code2, result2) {
        cb();
      });
    }
  });
}, function(err) {
  if (err) {
    console.log('An error ocurred');
  } else {
    console.log('Nothing happens');
  }
});