Day Five - Free Internship - Web Designing & Development

Introduction

Good evening everyone! I hope my voice is audible and that you're able to see the screen clearly. Over the past four days, we have been diving deep into PHP, including integrating content and backend systems. Just a quick reminder, I assigned you an exercise to store data, and I encourage you to take your time to complete it. Remember, even if you encounter errors, that's part of the learning process.

On the previous days we reviewed a couple of MySQL commands, including:

1. Data Definition Language (DDL) - Focuses on table structure commands like CREATE, ALTER, and DROP.
2. Data Manipulation Language (DML) - Concerned with data change commands like INSERT, UPDATE, and DELETE.

MySQL Queries

We practiced creating tables using the CREATE TABLE command and learned how to insert data using the INSERT INTO command. For example, to create a table named users could look like this:

CREATE TABLE users (
    name VARCHAR(20)
);

We then learned that you can also create a database using the command:

CREATE DATABASE database_name;

For practical exercises, I suggested using SQL online editors where you can practice commands without needing a local setup.

Next, we explored the UPDATE command used for modifying existing data. The syntax involves specifying the table name, the values to update, and a condition to determine which rows to update:

UPDATE table_name
SET column_name = new_value
WHERE condition;

We then processed an example where we updated a customer's first name by specifying the customer ID as the condition.

Selecting Data

The SELECT command is crucial for retrieving data. It can display all data with:

SELECT * FROM customers;

Or just specific columns with:

SELECT first_name, country FROM customers;

We also learned how to filter results with conditions, using operators like IN, AND, and OR.

Wildcards Searching

For pattern-based searching, the LIKE operator is essential. It allows for flexible queries even when you don’t know the exact data in a table. Two important wildcards include:

• Percentage (%): Represents zero or more characters.
• Underscore (_): Represents a single character.

For instance, WHERE name LIKE 'J%' will find names starting with "J", while WHERE name LIKE 'S_W%' targets names that start with "S", have any character in the second position, and then "W".

Joins

Finally, we discussed the concept of joins to combine data from multiple tables. For instance, if we wanted to understand what item John bought, we could use an INNER JOIN on the customer and orders tables linked by customer_id.

Assignments and Additional Tools

After running through the SQL queries and concepts, I assigned tasks for today, requiring you to:

1. Create a search and edit form in HTML and connect it with PHP.
2. Download and redesign a one-page template.
3. Utilize Wix, a user-friendly website builder, to create a portfolio website.

Wix allows easy drag-and-drop designing, making it perfect for those who prefer not to code. You can add images, change text, and adjust styles simply and effectively.

Remember to fill out your attendance sheet and submit your assignments, as these will be assessed for potential internship opportunities with us.

As for your certificates, they will be sent out next week. Keep an eye on the WhatsApp channel for updates.

Keywords

• PHP
• MySQL
• SQL Commands
• Data Definition Language
• Data Manipulation Language
• Wildcards
• Joins
• Website Builder
• Wix
• Internship

FAQ

1. What is DDL in MySQL?
DDL stands for Data Definition Language, which includes commands for defining database structures like tables.

2. What is DML in MySQL?
DML stands for Data Manipulation Language, which includes commands to manipulate data in a database such as INSERT, UPDATE, and DELETE.

3. How do I update a record in SQL?
You can update records using the UPDATE statement followed by the SET clause to specify changes with a WHERE condition.

4. What is the purpose of the SELECT statement?
The SELECT statement is used to retrieve data from a database, allowing you to specify which columns to view and apply filtering conditions.

5. How do wildcards work in SQL?
Wildcards are special characters used in SQL to represent unknown characters in a query. % represents zero or more characters, while _ represents a single character.

6. What are joins in SQL?
Joins are used to combine rows from two or more tables based on related columns, enabling complex queries that retrieve information from multiple tables.