Merge pull request HackYourFuture#184 from HackYourFuture/unmesh

unmeshvrije · web-flow · commit 724aebefd2fa · 2018-12-03T14:03:36.000+01:00
update README of lesson 1
diff --git a/Week1/MAKEME.md b/Week1/MAKEME.md
@@ -1,52 +1,24 @@
 # Homework week 1
-
-## Draw a database design for a TODO App
-
-If you want to use software to do this use MySQL workbench or LucidCharts
-(online option)  And a tutorial on how to create an Entity-Relation-Diagram
-(ERD) (<https://www.youtube.com/watch?v=9L0CMnDGuLg>). Otherwise pen and paper
-is just fine, but take a picture put it in the homework directory! 
-
-*(Note: It's not important you learn how to use a specific drawing tool but it
-is important you learn how to design a database!)*
-
-Design a database for an app that keeps track of TODO lists of its users. In
-this app a user can:
-
-- Create a TODO item with some text in it
-- Add tags to the TODO items, like `homework`, `groceries` etc..
-- Mark a TODO item as done
-
-**Bonus round:**
-
-Write a `todo.sql` file and put it in the homework folder where you create the
-database structure from your ERD
-<https://www.w3schools.com/sql/sql_create_table.asp>. Make sure you can use the
-`source` command in MySQL to create the database.
-
-## World database queries!
-
-Create a database called `world` and `source` the SQL data into the database [databases/world.sql](databases/world.sql).
-
-*(Remember: first `create` the database, then `use` it, and then `source` the `world.sql` file.)*
-
-Some SQL refresh tutorial (if needed):
-
-- <https://www.w3schools.com/sql/sql_select.asp>
-- <http://www.geeksforgeeks.org/sql-tutorial/>
-
-Answer the following questions using the `world` database and put your answers
-in [homework/world-queries.txt](homework/world-queries.txt). You will have to
-use keywords that we did not see in class: `ORDER BY`, `LIMIT`, `GROUP BY`:
-
-*(Hint: Use `SHOW tables;` and `DESCRIBE <table>;` to see what the table structure looks like)*
-
-1. What are the names of all the cities in the Netherlands?
-2. What is the population of Rotterdam ?
-3. What's the name of all the countries on the continent ‘North America’ ? 
-4. What's the top 10 countries by SurfaceArea ?
-5. What's the top 10 most populated cities?
-6. Select the top 3 countries by population that their names start with the letter ‘P’
-7. What is the population in Asia?
-8. Which languages are spoken in the Region of ‘South America’
-9. What are the languages spoken on all cities named ‘Barcelona’ (you may need to join 3 tables =) )
+```
+Write a node-JS program to
+1. create a database world
+2. create a table country
+3. create a table city 
+4. Insert 10-20 rows in each table with relevant fields. 
+
+Choose the fields/columns such that you should be able to answer the following queries:
+(Queries 6-10 are bonus queries and require the knowledge of joins, group by and having clauses)
+
+Write a node-JS program to query (using select statements) the world database to answer following questions
+1. What are the names of countries with population greater than 8 million
+2. What are the names of countries that have “land” in their names ?
+3. What are the names of the cities with population in between 500,000 and 1 million ?
+4. What's the name of all the countries on the continent ‘Europe’ ?
+5. List all the countries in the descending order of their surface areas.
+6. What are the names of all the cities in the Netherlands?
+7. What is the population of Rotterdam ?
+8. What's the top 10 countries by Surface Area ?
+9. What's the top 10 most populated cities?
+10. What is the population of the world ?
+
+```
diff --git a/Week1/README.md b/Week1/README.md
@@ -1,42 +1,167 @@
-# Lesson 1: Retrieving Data
+# Lesson 1: MySQL and Node setup! Create, Insert and Select !
 
-In this class, students will be introduced to relational data terminology (row, column), the function of a primary key, and retrieving data from a MySQL database using SELECT queries.
+Objective : This module aims to incorporate JavaScript code to operate the MySQL database.
+MySQL client can be used to demonstrate SQL queries however, students should know how to
+make a MySQL database connection from JavaScript, run queries from JavaScript and
+capture results of queries in JavaScript.
 
-Objective: Students should be able to retrieve data from a database table using SELECT statements that include WHERE, GROUP BY, and ORDER BY.
-
-## Pre-Class Readings
+## Pre-Class Preparation
+- Install MySQL using the following [official docs](https://dev.mysql.com/downloads/mysql/)
+- MAC users may use `brew install mysql`
 
 Before arriving to class on Sunday, please watch all of the videos in [this video playlist](https://www.lynda.com/SharedPlaylist/0299ced540444d7197460e7f1f74ddab) on Lynda.
-- What are databases?
-- Exploring databases and database management systems
-- The features of a relational database
-- Introduction to database modeling
-- Using the basic SELECT statement
-- Creating SQL queries
-- Structuring the WHERE clause
-- Sorting query results
-- Using aggregate functions
-- Joining tables
+If you actually manage to watch them all and understand everything,
+then you are a database expert.
 
-## Pre-Class Preparation
-- Install MySQL windows guys can follow the [official docs](https://dev.mysql.com/doc/refman/5.7/en/windows-installation.html) unix users have it easyier as usual 😉
+## Setup
+
+### MySQL setup
+This setup assumes MySQL version 8.0.
+Windows users should use **Microsoft MySQL Command Line** client.
+Linux and MAC users should use **gnome-terminal** and **Terminal** respectively.
+**Microsoft MySQL Command Line** client gives you a **msql>** prompt after typing in your root password.
+Note that this password is the one you used for root user of the mysql.
+Linux and MAC users can execute `mysql -uroot -p` and then type the password.
+Following commands should be run under the **mysql>** prompt:
+```
+mysql> create user ‘hyfuser’@‘localhost’ identified with mysql_native_password by ‘hyfpassword’;
+# This command creates a user 'hyfuser' with password 'hyfpassword' for
+# the database server at 'localhost'
+
+mysql> grant all privileges on *.* to ‘hyfuser’@‘localhost’;
+# This command gives all permissions to user 'hyfuser'.
+(*.*) means every table of every database.
+
+mysql> create database userdb;
+This command creates a database 'userdb'
+```
+
+### Node setup
+This setup assumes that you have Node.js 0.6 or higher.
+We use **mysqljs** driver which can be installed using `npm install mysql`
+
+### Verification of the correct setup
+Run `node connection-test.js` from VScode(Windows) or the terminal(Linux or MAC).
+The output should be `The solution is:  2`.
+connection-test.js can be found in the Week1 folder.
+
+In this class, students will be introduced to
+
+* Basics of relational databases: Concepts of tables, rows, columns, primary key, foreign key.
+* Creation of a database table and insertion of values.
+* Retrieving data from a MySQL database using SELECT queries.
+
+Objective: Students should be able to create tables,
+insert values in tables and
+retrieve data from tables using SELECT statements that include FROM, WHERE clauses.
+
+
+## Topics to be covered
+
+### What is a Database ?
+* Definition : Organized collection of data and rules about its manipulation
+* Client-server architecture : E.g. (Relational) DBMS
+* Files as database
+* Data structure/object as database
+```js
+const capitals = [
+  "Amsterdam",
+  "Delhi",
+  "Damascus",
+  "Madrid"];
+```
+
+### Relations = Table
+
+* What is a relation (in the following sentences)?
+* Delhi is the capital of India
+* Amsterdam is the capital of Netherlands
+* Damascus is the capital of Syria
+
+Dan, 29, works in Amazon and lives in Seattle. His friend Ben who just celebrated
+his 24th birthday works in Facebook and lives in Redmond.
+
+### DBMS implementations
+
+* **MySQL**
+* PostgreSQL
+* MongoDB (NoSQL)
+* Cassandra (NoSQL)
+
+### MySQL components
+
+* MySQL server (runs as a service, default port: 3306)
+* mysql: monitor / terminal / client (to connect to the server and execute stuff)
+* mysqladmin: Administering a MySQL Server
+
+### Create a table in MySQL
+
+#### Collection of rows and columns
+#### SYNTAX
+```
+CREATE TABLE table_name (column_name, column_type [, column2_name, column2_type]);
+```
+
+* INT(N) type
+* DATE, DATETIME and TIMESTAMP, (set time_zone = '+03:00')
+* BLOB (LOAD_FILE(filename))
+
+
+### Fill up a table in MySQL: INSERT rows
+A row (aka record or tuple) represents a single, implicitly structured data item in the table.
+
+#### SYNTAX
+```
+INSERT INTO table_name VALUES(value1, value2 [,value3,...]);
+```
+* INSERT INTO table_name VALUES(...values...)
+* INSERT INTO table_name (column names) VALUES(..values...)
+* INSERT INTO table_name SET column_name = {expr | DEFAULT}
+
+### See the content of a table in MySQL: SELECT
+
+#### SYNTAX 
+```
+SELECT */column_1,column_2...
+FROM table_1
+[INNER | LEFT |RIGHT] JOIN table_2 ON conditions
+WHERE conditions
+GROUP BY group 
+HAVING group_conditions
+ORDER BY column_1 [ASC | DESC]
+LIMIT offset, row_count
+ 
+The SELECT statement is composed of several clauses:
+ 
+  -  SELECT chooses which columns of  the table you want to get the data.
+  -  FROM specifies the table from which you get the data.
+  -  JOIN gets data from multiple table based on certain join conditions.
+  -  WHERE filters rows to select.
+  -  GROUP BY group rows to apply aggregate functions on each group.
+  -  HAVING filters group based on groups defined by GROUP BY clause.
+  -  ORDER BY specifies the order of the returned result set.
+  -  LIMIT constrains number of returned rows.
+```
+
+### INSERT and SELECT together
 
+```
+Example: 
 
-## Main Topics
+INSERT INTO 'employees' ('shop_id', 'gender', 'name', 'salary')
+SELECT 3,
+       LEFT(gender, 1),
+       CONCAT_WS(' ', first_name, last_name),
+       salary
+FROM   transferred_ employees
+WHERE  transfer_date > '2008-01-01';
+```
 
-- The relational model of data
-- A 'database' vs. a 'DBMS' (database management system)
-- The concept of a schema
-- The properties of an 'entity' (or 'row')
-- Basic entity relationship diagrams
-- A basic SELECT statement
-- Constructing more complex SELECT statements
-- JOIN
-    - Selecting composite data from multiple tables
-    - Compare JOIN WHERE with cartesian product
-- Naming Conventions: UpperCamelCase/PascalCase, lowerCamelCase, snake_case, hnHungarianNotation/HNHungarianNotation
-- Character Sets in Databases (hint: always use UTF-8 encoding, called 'utf8mb4' in MySQL)
+### Uniqueness and Keys
 
+* Super key : set of columns that uniquely identify a row
+* Candidate key : minimal super key that can uniquely identify a row
+* Primary key : choice of candidate key chosen by database designer : cannot be null
 
 ## Reference Material
 
diff --git a/Week1/create-table.js b/Week1/create-table.js
@@ -0,0 +1,19 @@
+var mysql      = require('mysql');
+var connection = mysql.createConnection({
+  host     : 'localhost',
+  user     : 'hyfuser',
+  password : 'hyfpassword',
+  database : 'class17'
+});
+
+connection.connect();
+
+var create_query = "create table teachers (teacher_number int, teacher_name varchar(50), date_of_birth date, subject text, gender enum('m', 'f'))"
+
+connection.query(create_query, function (error, results, fields) {
+    if (error) {
+        throw error;
+    }
+    console.log("the reply is ", results[0]);
+});
+connection.end();
diff --git a/Week1/homework/world-queries.txt b/Week1/homework/world-queries.txt
diff --git a/Week1/insert-values.js b/Week1/insert-values.js
@@ -0,0 +1,26 @@
+var mysql      = require('mysql');
+var connection = mysql.createConnection({
+  host     : 'localhost',
+  user     : 'hyfuser',
+  password : 'hyfpassword',
+  database : 'class17'
+});
+
+connection.connect();
+var insert_queries = [
+                    "insert into students values (103, 'Ahmad', '1986-01-11', 8.3, 'm')",
+                    "insert into students values (104, 'Rim', '1979-11-01', 8.7, 'f')",
+                    "insert into students values (105, 'Rabia', '1978-05-30', 8.1, 'f')",
+                    "insert into students values (106, 'Karam', '1994-02-02', 8.8, 'm')"
+                    ]
+
+for(var i in insert_queries){
+    console.log("Going to run ", insert_queries[i])
+    connection.query(insert_queries[i], function (error, results, fields) {
+        if (error) {
+            throw error;
+        }
+        console.log("the reply is ", results[0]);
+    });
+}
+connection.end();
diff --git a/Week1/select-star.js b/Week1/select-star.js
@@ -0,0 +1,22 @@
+var mysql      = require('mysql');
+var connection = mysql.createConnection({
+  host     : 'localhost',
+  user     : 'hyfuser',
+  password : 'hyfpassword',
+  database : 'class17'
+});
+
+connection.connect();
+
+var select_query = "select * from students"
+
+console.log("Going to run ", select_query)
+connection.query(select_query, function (error, results, fields) {
+    if (error) {
+        throw error;
+    }
+    for (i in results) {
+        console.log(results[i]);
+    }
+});
+connection.end();
