SQL: Query data with SELECT

You can get data out of tables using the SELECT command.

Get all rows and columns:

SELECT * FROM people;

This is query.

You can see the result below:

You can use this tool to get any data out of the database, combine multiple tables, filter data… it’s super powerful.

Let’s do a few examples.

Get only the name column:

SELECT name FROM people;

Count the items in the table:

SELECT COUNT(*) from people;

You can filter rows in a table adding the WHERE clause:

SELECT age FROM people WHERE name='Tony';

The results of a query can be ordered by column value, ascending (the default) or descending, using ORDER BY:

SELECT * FROM people ORDER BY name;

SELECT * FROM people ORDER BY name DESC;

Use LIMIT to limit the number of results returned:

SELECT * FROM people ORDER BY name DESC LIMIT 2;

Lessons in this unit:

0: Introduction
1: Using TablePlus
2: Create a Postgres database
3: Create a new table
4: Add data to a table
5: ▶︎ Query data with SELECT
6: Delete data from the database
7: Update data with UPDATE
8: Null constraints
9: Unique and primary keys
10: Updating a table structure
11: Joins