📗 Ordering Data

Welcome to the Selecting Data module! This foundational learning path is designed to help you master the basics of querying data, particularly focusing on how to retrieve specific information from databases effectively.

📘 Creating SQL Table

In this tutorial, you'll learn how to interpret and use rows in a database table. Tables are essential to storing structured data, and each row in a table represents a unique item or record.

Each row of a table represents a new item.

Each column of a table represents a specific attribute of the data, such as id, name, or username. These columns define the type of information stored for each item in the table.

For example, consider a table named Friends. Below is how a simple table might look:

Task: Sort a table using the ORDER BY clause

Lesson Overview

After using ORDER BY, we specify the column by which we want to order the entries.
For example, to sort by the name column:

The first step in ordering table is the SELECT ORDER BY helps you to arrange data in readable form Here FROM specify the table we are selecting from ountries. Here the query is ordering the number by name/.

info

SQL Table

Friends

| name    | username |
-----------|---------|
Smith     | 19      |
Jones     | 60      |
Wilson    | 25      |

SQL Code

Creating SQL Tables & db.

-- creating orders
SELECT * FROM patients
ORDER BY name;

Output

name	age
Smith	19
Jones	60
Wilson	25

Example Practice

To query data from a table, use the FROM clause followed by the table's name.

For example, consider a table named Friends. Below is how a simple table might look:

info

SQL Table

Friends

| name    | gdp     |
|---------|---------|
| Greece  | 187.46  |
| Sweden  | 474.15  |
| Iceland | 21.6    |
| Germany | 3449.05 |

SQL Code

Creating SQL Tables.

SELECT *
FROM countries
ORDER BY name;

Output

name	gdp
Germany	3449.05
Greece	187.46
Iceland	21.6
Sweden	474.15

tip

When requesting data with SQL staments like SELECT, we say that we are making a query. From helps in select the name col from While not necessary but its a good practice to finish the sql queries with;

By following these best practices, ASC is the default sort ordering method followed.

🔄 Arranging ORDERS BY with ASC , DESC

info

Ordering text properties like name is different when comparing to the age We can order items in asseding starting with smalest value or deceding.

SQL Table

friends

| name   | age |
|--------|-----|
| Smith  | 19  |
| Jones  | 60  |
| Wilson | 25  |

SQL Code

Creating SQL Tables.

SELECT *
FROM patients
ORDER BY age ASC;

Output

name	age
Smith	19
Wilson	25
Jones	60

🧹 Selecting with DESC

For Text value it order by Alphabetically When arranging numerical value the item with smallest value in that coloumn comes first

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info

SQL Table

Subscribers

| name   | age |
|--------|-----|
| Smith  | 19  |
| Jones  | 60  |
| Wilson | 25  |

SQL Code

Creating SQL Tables.

SELECT *
FROM patients
ORDER BY age DESC;

Output

name	age
Jones	60
Wilson	25
Smith	19

✅ What You Have Learned

This module covers essential concepts related to ordering data in SQL:

• ORDER BY Clause
  Learn how to sort query results based on one or more columns using the ORDER BY keyword.

• Ascending Order (ASC)
  Understand that SQL sorts in ascending order by default, which is the same as explicitly using ASC.

• Descending Order (DESC)
  Use the DESC keyword to sort results from highest to lowest or reverse alphabetical order.

• Sort by Column Values
  Practice sorting by numeric or text column values to organize data meaningfully.

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