Added price history log.

app/crawler/savers/postgres.js

@@ -1,6 +1,7 @@
 const moment = require("moment");
 
 const { bulkUpsertRealEstates } = require("../../helpers/db/realEstate");
+const { bulkUpsertPriceHistory } = require("../../helpers/db/priceHistory");
 
 class PostgresSaver {
   connect() {
@@ -11,6 +12,21 @@ class PostgresSaver {
 
   async save(results) {
     const savedRecords = await bulkUpsertRealEstates(results);
+    //Extruding data for price history table
+    const resultPrices = savedRecords.map(realEstate => {
+      //Null values canot be recognized by ignore duplicates in sequalize
+      //Value price = 0 indicates 'cijena na upit'
+      const priceTmp =
+        realEstate.dataValues.price === null ? 0 : realEstate.dataValues.price;
+
+      return {
+        realEstateId: realEstate.dataValues.id,
+        price: priceTmp,
+        createdAt: realEstate.dataValues.createdAt,
+        updatedAt: realEstate.dataValues.updatedAt
+      };
+    });
+    const savedPrices = await bulkUpsertPriceHistory(resultPrices);
 
     if (Array.isArray(savedRecords)) {
       const newRealEstates = [];

app/helpers/db/priceHistory.js

@@ -0,0 +1,20 @@
+"use strict";
+const db = require("../../models/index");
+const sequelize = require("sequelize");
+
+const bulkUpsertPriceHistory = async priceHistoryData => {
+  try {
+    const order = [["realEstateId", "desc"]];
+
+    return await db.PriceHistory.bulkCreate(priceHistoryData, {
+      order,
+      ignoreDuplicates: true
+    });
+  } catch (e) {
+    console.log("Error bulk upserting priceHistory : ", e);
+  }
+};
+
+module.exports = {
+  bulkUpsertPriceHistory
+};

app/migrations/20200121000524-add-priceHistory-table.js

@@ -0,0 +1,42 @@
+"use strict";
+
+module.exports = {
+  up: (queryInterface, Sequelize) => {
+    const tableFields = {
+      id: {
+        type: Sequelize.BIGINT,
+        autoIncrement: true,
+        allowNull: false,
+        primaryKey: true
+      },
+      realEstateId: {
+        type: Sequelize.BIGINT,
+        allowNull: false,
+        unique: "uniquePriceRealEstate",
+        references: {
+          model: "RealEstates",
+          key: "id"
+        },
+        onUpdate: "CASCADE",
+        onDelete: "SET NULL"
+      },
+      price: {
+        type: Sequelize.REAL,
+        unique: "uniquePriceRealEstate"
+      },
+      createdAt: {
+        type: Sequelize.DATE,
+        defaultValue: Sequelize.literal("NOW()")
+      },
+      updatedAt: {
+        type: Sequelize.DATE,
+        defaultValue: Sequelize.literal("NOW()")
+      }
+    };
+    return queryInterface.createTable("PriceHistory", tableFields);
+  },
+
+  down: queryInterface => {
+    return queryInterface.dropTable("PriceHistory", {});
+  }
+};

app/migrations/20200121094500-add-constraint-priceHistory.js

@@ -0,0 +1,10 @@
+"use strict";
+module.exports = {
+  up: (queryInterface, Sequelize) =>
+    queryInterface.addConstraint("PriceHistory", ["realEstateId", "price"], {
+      type: "unique",
+      name: "uniquePriceRealEstate"
+    }),
+  down: queryInterface =>
+    queryInterface.removeConstraint("PriceHistory", "uniquePriceRealEstate")
+};

app/models/priceHistory.js

@@ -0,0 +1,44 @@
+"use strict";
+
+module.exports = (sequalize, DataTypes) => {
+  const PriceHistory = sequalize.define(
+    "PriceHistory",
+    {
+      id: {
+        type: DataTypes.BIGINT,
+        autoIncrement: true,
+        primaryKey: true,
+        allowNull: false
+      },
+      realEstateId: {
+        type: DataTypes.BIGINT,
+        allowNull: false,
+        unique: "uniquePriceRealEstate",
+        references: {
+          model: "RealEstates",
+          key: "id"
+        },
+        onUpdate: "CASCADE",
+        onDelete: "SET NULL"
+      },
+      price: {
+        type: DataTypes.REAL,
+        unique: "uniquePriceRealEstate"
+      }
+    },
+    {
+      freezeTableName: true
+    }
+  );
+
+  PriceHistory.associate = models => {
+    PriceHistory.hasMany(models.RealEstate, {
+      foreignKey: "id",
+      sourceKey: "realEstateId",
+      targetKey: "id",
+      as: "realEstates"
+    });
+  };
+
+  return PriceHistory;
+};

app/seeders/20200121150443-initial-price-history.js

@@ -0,0 +1,34 @@
+"use strict";
+
+const { RealEstate } = require("../models");
+
+module.exports = {
+  async up(queryInterface, Sequelize) {
+    //Reading initial data from RealEstate table in db
+    const realEstateInitialData = await RealEstate.findAll();
+    //Extruding data for table PriceHistory
+    const priceHistoryInitialData = realEstateInitialData.map(realEstate => {
+      //Null values canot be recognized by ignore duplicates in sequalize
+      //Value price = 0 indicates 'cijena na upit'
+      const priceTmp =
+        realEstate.dataValues.price === null ? 0 : realEstate.dataValues.price;
+
+      return {
+        realEstateId: realEstate.dataValues.id,
+        price: priceTmp,
+        createdAt: realEstate.dataValues.createdAt,
+        updatedAt: realEstate.dataValues.updatedAt
+      };
+    });
+
+    return queryInterface.bulkInsert(
+      "PriceHistory",
+      priceHistoryInitialData,
+      {}
+    );
+  },
+
+  async down(queryInterface, Sequelize) {
+    return queryInterface.bulkDelete("PriceHistory", null, {});
+  }
+};

package.json

@@ -8,6 +8,7 @@
     "start": "node ./index.js",
     "start-mon": "nodemon ./index.js",
     "migrate": "cd app && npx sequelize db:migrate",
+    "seed": "cd app && npx sequelize db:seed:all",
     "setup": "docker build -t marketalerts .  && docker run -e POSTGRES_USER=docker -e POSTGRES_PASSWORD=docker -e POSTGRES_DB=marketalerts --name pg_marketalerts -d -p 5432:5432 marketalerts && sleep 10 && npm run migrate",
     "docker-start": "docker start pg_marketalerts",
     "docker-stop": "docker stop pg_marketalerts",