Simple SQL Queries for Beginners: SELECT, ORDER BY, CASE WHEN
Jun 17, 2024
In this video, we'll walk through some basic SQL queries using a small, generated table. This setup allows you to follow along without needing any pre-existing database.
Getting Started
We'll use an SQL query cheat sheet, available for free download in the video description. The queries are executed live on an SQL server, but they should work on other databases as well. The data is generated on the fly, making it easy for you to replicate.
Our Table Structure
| EmployeeId | DepartmentId | First Name | Last Name | Salary | ManagerId |
|---|---|---|---|---|---|
| 1 | 1 | Ben | Smith | 100000 | NULL |
| 2 | 1 | John | Miller | 80000 | 1 |
| 3 | 2 | Ed | Jones | 65000 | 1 |
| 4 | 2 | Ben | Holmes | 70000 | 1 |
| 5 | NULL | Norman | Brown | 1000 | 1 |
Basic SQL Queries
Select All Data
To select all data from the table:
Select Specific Columns
To retrieve specific columns, such as first_name and last_name:
Ordering Data
To sort the data by a specific column:
To sort in descending order:
Limiting Results
To limit the number of rows returned:
Distinct Values
To get unique values from a column:
Conditional Statements
To add conditional logic with the CASE WHEN statement:
Conclusion
These basic SQL queries will help you get started. For more detailed instructions and examples, download the SQL Query Cheat Sheet and follow along with the queries in the GitHub repository. Happy querying!
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