SequelizeEagerLoadingError：（父）未关联到（子）！

Question

我正在使用 sequelize 构建一个应用程序。我目前有 3 张桌子；用户、游览和位置。位置与巡回赛具有 n:1 的关系。 Tour 与用户具有 n:1 的关系。

没有用户关联，其他两个表工作正常。一旦我添加了用户关联（并且我尝试通过迁移和删除然后重新创建我的整个数据库来做到这一点），我得到一个 SequelizeEagerLoadingError: Location is not associated with Tour！

这是我的模型：

module.exports = function(sequelize, DataTypes) {
  var Location = sequelize.define("Location", {
    title: {
      type: DataTypes.STRING,
      allowNull: false
    },
    description: {
      type: DataTypes.TEXT,
      allowNull: false,
      validate: {
        len: [500]
      }
    },
    address: {
      type: DataTypes.TEXT,
      allowNull: false
    }
  });

  Location.associate = function(models) {
    Location.belongsTo(models.Tour, {
      onDelete: "cascade"
    });
  };

  return Location;
};

module.exports = function(sequelize, DataTypes) {
  var Tour = sequelize.define("Tour", {
    title: {
      type: DataTypes.STRING,
      allowNull: false
        },
    description: {
      type: DataTypes.TEXT,
      allowNull: false,
      validate: {
        len: [1, 1000]
      }
    },
    neighborhood: {
      type: DataTypes.STRING,
      allowNull: false
    },
    URL: {
      type: DataTypes.TEXT,
      allowNull: false,
      validate: {
        len: [1, 1000]
      }
    },
    numberOfStops: DataTypes.INTEGER,
    duration: {
      type: DataTypes.INTEGER,
      allowNull: false
    },
    tags: DataTypes.STRING
  });

    Tour.associate = function(models) {
    Tour.hasMany(models.Location);
  };

  Tour.associate = function(models) {
    Tour.belongsTo(models.User);
  };

  return Tour;
};
 

var bcrypt = require("bcrypt-nodejs");
module.exports = function(sequelize, DataTypes) {
  var User = sequelize.define("User", {
    name: {
      type: DataTypes.STRING,
      allowNull: false
    },
    email: {
      type: DataTypes.STRING,
      allowNull: false,
      unique: true,
      validate: {
        isEmail: true
      }
    },
    password: {
      type: DataTypes.STRING,
      allowNull: false
    }
  });
  User.prototype.validPassword = function(password) {
    return bcrypt.compareSync(password, this.password);
  };

  User.hook("beforeCreate", function(user) {
    user.password = bcrypt.hashSync(
      user.password,
      bcrypt.genSaltSync(10),
      null
    );
  });

  User.associate = function(models) {
    User.hasMany(models.Tour);
  };

  return User;
};

这里是包含语句失败的地方，以及我们用 tourId 建立到该位置的链接：

app.get("/tour/:id", function(req, res) {
    db.Tour.findOne({
      where: { id: req.params.id },
      include: [db.Location]
    }).then(function(tour) {
      res.render("tour", {
        tour: tour
      });
    });
  });
  
  
  
  
   

var API = {
  saveTour: function(tour) {
    return $.ajax({
      headers: {
        "Content-Type": "application/json"
      },
      type: "POST",
      url: "api/tours",
      data: JSON.stringify(tour)
    });
  },
  saveLocations: function(locations) {
    return $.ajax({
      headers: {
        "Content-Type": "application/json"
      },
      type: "POST",
      url: "api/locations",
      data: JSON.stringify(locations)
    });
  },
  getUserId: function() {
    return $.ajax({
      type: "GET",
      url: "api/user_data"
    });
  }
};

var tour = {
    Users: thisUser.getUserId(),
    title: title,
    description: description,
    neighborhood: neighborhood,
    URL: URL,
    duration: duration,
    tags: tags
  };

  // console.log(tour);

  if (!errors.length) {
    // Post our tour to the Tours table, then reveal the form and set our local tour object.
    API.saveTour(tour).then(function(tour) {
      document.getElementById("submit-tour").remove();
      document.getElementById("tourstopssection").style.display = "block";
      thisTour.setId(tour.id);
    });
  }
}

// Function takes in the newly created tour object, grabs DOM values for each.
function addTourLocations(e) {
  e.preventDefault();
  // Grab and process all of our tour stops.
  var locationElements = document.getElementsByClassName("tourstop");
  var areStopErrors = false;
  var locations = [];

  // Loop over every location element on the DOM.
  for (var j = 0; j < locationElements.length; j++) {
    var children = locationElements[j].children;

    // Initialize this location with the tour id; we'll pass in data...
    var thisLocation = {
      TourId: thisTour.getId()
    };

    // ... by looping over the DOM children and grabbing their form values.
    for (var k = 0; k < children.length; k++) {
      if (
        children[k].classList.value.includes("stoptitle") &&
        children[k].value
      ) {
        var stopTitle = children[k].value;
        thisLocation.title = stopTitle;
      }

      if (
        children[k].classList.value.includes("stopaddress") &&
        children[k].value
      ) {
        var stopAddress = children[k].value;
        thisLocation.address = stopAddress;
      }

      if (
        children[k].classList.value.includes("stopdescription") &&
        children[k].value
      ) {
        var stopDescription = children[k].value;
        thisLocation.description = stopDescription;
      }
    }

    // Push this location into our locations array.
    locations.push(thisLocation);

最后，app/db 是这样同步的：

require("dotenv").config();
var express = require("express");
var session = require("express-session");
var exphbs = require("express-handlebars");
var helpers = require("./lib/helpers");

var db = require("./models");
var passport = require("./config/passport");

var app = express();
var PORT = process.env.PORT || 3000;

// Middleware
app.use(express.urlencoded({ extended: true }));
app.use(express.json());
app.use(express.static("public"));

var hbs = exphbs.create({
  defaultLayout: "main",
  helpers: helpers // Require our custom Handlebars helpers.
});

//Sessions are used to keep track of our user's login status
app.use(
  session({ secret: "keyboard cat", resave: true, saveUninitialized: true })
);
app.use(passport.initialize());
app.use(passport.session());
app.use(function(req, res, next) {
  res.locals.user = req.user; // Set a local variable for our user.
  next();
});

// Handlebars
app.engine("handlebars", hbs.engine);
app.set("view engine", "handlebars");

// Routes
require("./routes/apiRoutes")(app);
require("./routes/htmlRoutes")(app);

var syncOptions = { force: false };

// If running a test, set syncOptions.force to true
// clearing the `testdb`
if (process.env.NODE_ENV === "test") {
  syncOptions.force = true;
}

// Starting the server, syncing our models ------------------------------------/
db.sequelize.sync(syncOptions).then(function() {
  app.listen(PORT, function() {
    console.log(
      "==> ????  Listening on port %s. Visit http://localhost:%s/ in your browser.",
      PORT,
      PORT
    );
  });
});

module.exports = app;

我已经用谷歌搜索了四天....帮助！

Answer 1

尝试将此添加到您的关联中，还有为什么您在 Tour 上定义了两倍的关联功能？

module.exports = function(sequelize, DataTypes) {
  var Location = sequelize.define("Location", {
    //
  });

  Location.associate = function(models) {
    Location.belongsTo(models.Tour, { as:'Tour', foreignKey:'tourId', onDelete: "cascade"});
  };

  return Location;
};

module.exports = function(sequelize, DataTypes) {
  var Tour = sequelize.define("Tour", {
    //
  });

  Tour.associate = function(models) {
    Tour.hasMany(models.Location, { as: 'Locations', foreignKey: 'tourId'});
    Tour.belongsTo(models.User, { as: 'User', foreignKey: 'userId' });
  };


  return Tour;
};

module.exports = function(sequelize, DataTypes) {
  var User = sequelize.define("User", {
    //
  });

  User.associate = function(models) {
    User.hasMany(models.Tour, {as: 'Tours', foreignKey: 'userId'});
  };

  return User;
};

并在查询中添加相同的内容。

db.Tour.findOne({
  where: { id: req.params.id },
  include: [{ 
    model: db.Location,
    as: 'Locations'
  }]
}).then(function(tour) {
  res.render("tour", {
    tour: tour
  });
});

Answer 2

我想通了——我在 tour 模型上定义了两次关联的事实打破了一切。一旦我如上所述将它们组合在一起，一切都完美无缺！

还有一点需要注意 - sequelize 会自动分配外键和别名，所以我把这部分省略了。