SELECT statement in SQL
SELECT is a fundamental SQL command that is used to retrieve data from one or more tables in a database. It is one of the most commonly used commands in SQL for querying a database to fetch data that matches specific criteria.
The result of a SELECT query is called a result set (basically a new table).
Syntax
Inside a SELECT statement, you can specify which columns you want to have in your result set.
You can use a wildcard symbol * to select all available columns from a table.
SELECT *
FROM users
Sometimes it returns too many columns, so usually you want to specify the columns you want to get:
SELECT
id,
email,
country,
age
FROM users
Using SELECT for learning SQL
SELECT is the most fundamental and most used keyword in SQL. You’ll for sure use it a LOT to get data for creating reports, hunting for insights, etc.
You can also use SELECT statement to learn SQL and practice different expressions, operators, or functions.
For example, this is a valid SQL query, try running it:
SELECT 1
We’re basically telling the database “Give me 1” and you’ll get a result set with just a number.
In the same way, you can test a comparison operator =:
SELECT 1 = 2
My favorite trick is to use the SELECT statement for playing with SQL functions and see what they return and if I use them correctly. For example, if you want to check if the first element in the split_part() is indexed with 0 or 1 you can run a query like this:
SELECT split_part('Hello world', ' ', 1)
Database compatibility
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MySQL
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PostgreSQL
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SQLite
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Redshift
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Big Query
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Snowflake
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SELECT
