BASIC SELECT

Key moments

SELECT statement introduction — The SELECT statement is introduced as the primary tool for picking data out of a database.

Specific column example — A simple query is presented to grab the CustomerName and City columns from the Customers table.

General syntax defined — The general structure of the SELECT column list FROM table_name syntax is defined.

Executing the demo query — The example query selecting CustomerName and City is executed against the sample Customers table.

Wildcard selection — The asterisk wildcard is introduced as a way to select all columns in the table.

Lesson summary — The basic functionality of the SQL SELECT statement is summarized as easy to use.

Bottom line: You will be able to retrieve specific columns or all data from a single database table using the fundamental SQL SELECT statement. You will learn the basic syntax for specifying columns and the use of the asterisk wildcard character.

This lesson on BASIC SELECT is hands-on and example-driven. You will be able to retrieve specific columns or all data from a single database table using the fundamental SQL SELECT statement. You will learn the basic syntax for specifying columns and the use of the asterisk wildcard character.

What You'll Be Able To Do

Identify the purpose of the SELECT statement in SQL.
Write a query to retrieve specific, named columns from a table.
Construct a query to return all columns from a specified table.
Apply the correct syntax for listing columns and specifying the source table.
Differentiate between selecting named columns and using the asterisk wildcard.

Topics Covered in BASIC SELECT

SELECT statement introduction (0:00 - 0:15) — The SELECT statement is introduced as the primary tool for picking data out of a database.
Specific column example (0:15 - 0:30) — A simple query is presented to grab the CustomerName and City columns from the Customers table.
General syntax defined (0:30 - 0:45) — The general structure of the SELECT column list FROM table_name syntax is defined.
Executing the demo query (0:45 - 1:00) — The example query selecting CustomerName and City is executed against the sample Customers table.
Wildcard selection (1:00 - 1:15) — The asterisk wildcard is introduced as a way to select all columns in the table.
Lesson summary (1:15 - 1:30) — The basic functionality of the SQL SELECT statement is summarized as easy to use.

SQL Cheat Sheet

SELECT — Specifies which columns or expressions should be returned in the result set
```
SELECT CustomerName, City
```
FROM <table> — Indicates the source table containing the data to be retrieved
```
FROM Customers;
```
SELECT col1, col2 FROM table; — Retrieves only the specified columns from the designated table
```
SELECT CustomerName, City FROM Customers;
```
* — Wildcard representing all columns in the specified table
```
SELECT * FROM Customers;
```

Comparison Table

Method	Syntax Example	Columns Returned
Specific Selection	SELECT CustomerName, City	Only CustomerName and City
Wildcard Selection	SELECT *	All columns in the table
General Form	column one, column two, etc.	Only the explicitly listed columns

Common Pitfalls

Mistake: Running a SELECT statement without specifying the source table. Avoid: Always include the FROM table_name clause after listing columns.
Mistake: Putting the table name in the column list or vice versa. Avoid: List columns after SELECT and the table after FROM.
Mistake: Using SELECT * when only two columns are needed. Avoid: Specify only the required column names for clarity and efficiency.
Mistake: Forgetting to separate multiple column names with a comma. Avoid: Use a comma (,) between every column name in the list.

FAQs

What is the purpose of the semicolon at the end of the query? The semicolon (;) is a statement terminator. It signals to the database that the current SQL command is complete and ready to be executed.
Do I need to capitalize SELECT and FROM? SQL keywords are generally case-insensitive, meaning the query will run either way. However, capitalization is standard practice for readability.
Can I select columns from multiple tables at once? Yes, but retrieving data from multiple tables requires using JOINs. This basic lesson focuses only on selecting data from a single table.

Hey there, future data wizards. Let's look at the SELECT statement. Think of it as your trusty tool for picking data out of a database, like choosing your favorite candies from a jar. So let's get started. The SELECT statement is used to grab data from a database. Here's a simple example to warm up. This code tells the database, "Hey, give me the customer name and city columns from the customers table." But how do we write this in a general form? Here's the syntax. Column one, column two, etc. are the columns you want, and table name is the table you're getting them from. Now, let's look at our demo database, the customers table. Here's a sneak peek. Let's do our SELECT statement from earlier. `SELECT CustomerName and City from Customers`. Pretty cool, right? But what if we want to see everything in the table? We use the star wildcard, like this. This tells the database, "Show me all the columns." And you get the whole shebang. And that's the basics of the SQL SELECT statement. Easy peasy, right? Thanks for watching. Like and subscribe to get notified about our latest videos. For more coding tips and tricks, keep it locked right here on w3schools.com. Don't forget to try out what you've learned in our interactive editor. Happy coding.

Frequently asked questions

What is the purpose of the semicolon at the end of the query?

The semicolon (;) is a statement terminator. It signals to the database that the current SQL command is complete and ready to be executed.

Do I need to capitalize SELECT and FROM?

SQL keywords are generally case-insensitive, meaning the query will run either way. However, capitalization is standard practice for readability.

Can I select columns from multiple tables at once?

Yes, but retrieving data from multiple tables requires using JOINs. This basic lesson focuses only on selecting data from a single table.

Ready to continue?