implements a category route

models/CategoryModel.js

@@ -0,0 +1,50 @@
+const db = require('../db/Pool');
+const pgp = require('pg-promise')({ capSQL: true });
+
+module.exports = class CategoryModel {
+    async getAll() {
+        try {
+            const statement = "SELECT * FROM category";
+            const result = await db.query(statement);
+            if (result.rows.length) return result.rows;
+            return null;
+        } catch(e) {
+            throw new Error(e);
+        }
+    }
+
+    async getById(id) {
+        try {
+            const statement = "SELECT * FROM category WHERE id = $1";
+            const values = [id];
+            const result = await db.query(statement, values);
+            if (result.rows.length) return result.rows;
+            return null;
+        } catch(e) {
+            throw new Error(e);
+        }
+    }
+
+    async getByName(name) {
+        try {
+            const statement = "SELECT * FROM category WHERE name = $1";
+            const values = [name];
+            const result = await db.query(statement, values);
+            if (result.rows.length) return result.rows;
+            return null;
+        } catch(e) {
+            throw new Error(e);
+        }
+    }
+
+    async insertOne(data) {
+        try {
+            const statement = pgp.helpers.insert(data, null, 'category') + "RETURNING *";
+            const result = await db.query(statement);
+            if (result.rows.length) return result.rows;
+            return null;
+        } catch(e) {
+            throw new Error(e);
+        }
+    }
+}