Retos Tema 2

Author: Cristina Taboada

Diff for: RetosTema2/main.js

@@ -0,0 +1,76 @@
+const mysql = require('mysql2/promise');
+
+const connect = async()=>{
+    try{
+        const connection = await mysql.createConnection({
+            host: 'localhost',
+            user: 'root',
+            password: 'Secur3MyS4QL',
+            database: 'escuela'
+        });
+
+        console.log('Conexión correcta');
+
+
+        //-- Nota media
+        const sql1 = `SELECT AVG(mark) FROM marks WHERE subject_id=1;`;
+        const [result1] = await connection.execute(sql1);
+        console.log('------Nota-media-asignatura-1------');
+        console.log(result1);
+
+        //-- Total alumnos
+        const sql2 = `SELECT COUNT(*) FROM students;`;
+        const [result2] = await connection.execute(sql2);
+        console.log('------Total-alumnos------');
+        console.log(result2);
+
+        //-- Listar campos de la tabla students_groups
+        const sql3 = `SELECT * FROM students_groups;`;
+        const [result3] = await connection.execute(sql3);
+        console.log('------Campos-de-la-tabla-groups------');
+        console.log(result3);
+
+        //-- Eliminar todas las notas > 5 del año pasado
+        // const sql4 = `DELETE FROM marks WHERE (mark > 5) AND (date < curdate() AND date > DATE_SUB(NOW(),INTERVAL 1 YEAR));`;
+        // const [result4] = await connection.execute(sql4);
+        // console.log('Notas > 5 del año pasado eliminadas');
+
+        //-- Listar estudiantes del año en curso
+        const sql5 = `SELECT * FROM students WHERE year = YEAR(NOW());`;
+        const [result5] = await connection.execute(sql5);
+        console.log('------Estudiantes-del-año-en-curso------');
+        console.log(result5);
+
+        //-- Calcular el número de profes por asignatura
+        const sql6 = `SELECT subject_id, COUNT(*) FROM teachers GROUP BY subject_id;`;
+        const [result6] = await connection.execute(sql6);
+        console.log('------Profes-por-asignatura------');
+        console.log(result6);
+
+        //-- Obtén el id y la nota de los alumnos que tengan un id entre 1 y 20,
+        //-- o que tenga una nota mayor de 8 y la nota tenga fecha del año pasado.
+        const sql7 = `SELECT student_id, mark FROM marks WHERE (student_id BETWEEN 1 AND 20) OR (mark > 8) AND (date BETWEEN curdate() AND DATE_SUB(NOW(),INTERVAL 1 YEAR));`;
+        const [result7] = await connection.execute(sql7);
+        console.log('------ID-entre-1y20-O-nota>8-del-año-pasado------');
+        console.log(result7);
+
+        //-- Media de las notas que se han dado en el último año por asignatura.
+        const sql8 = `SELECT subject_id,AVG(mark) FROM marks WHERE (date BETWEEN DATE_SUB(NOW(),INTERVAL 1 YEAR) AND curdate()) GROUP BY subject_id;`;
+        const [result8] = await connection.execute(sql8);
+        console.log('------Media-notas-ultimo-año-por-asignatura------');
+        console.log(result8);
+
+        //-- Media de las notas que se han dado en el último año por alumno.
+        const sql9 = `SELECT student_id,AVG(mark) FROM marks WHERE (date BETWEEN DATE_SUB(NOW(),INTERVAL 1 YEAR) AND curdate()) GROUP BY student_id;`;
+        const [result9] = await connection.execute(sql9);
+        console.log('------Media-notas-ultimo-año-por-alumno------');
+        console.log(result9);
+
+
+    }catch(err){
+        console.log(err);
+        await connection.end();
+    }
+};
+
+connect();