Selecting Specific Columns

While SELECT * is convenient, it's often better to specify exactly which columns you need. This makes your queries clearer and can improve performance.

Selecting One Column

SELECT column_name FROM table_name;

Selecting Multiple Columns

Separate column names with commas:

SELECT column1, column2, column3 FROM table_name;

Exercises

Why Specify Columns?

There are several reasons to list specific columns instead of using *:

1. Clarity: Your query shows exactly what data you need
2. Performance: The database only fetches the columns you request
3. Stability: If the table structure changes, your query still works
4. Documentation: Other developers can understand your intent

Free Practice

Try selecting different combinations:

• Just id and created_at
• All columns related to location (city)
• All columns related to the person (name, age)