How to use SELECT Statement? SQL Part 2

Select Statement:

It is one of the most basic statements in SQL as it allows us to retrieve information from a table.

Like: SELECT column_name FROM table_name

So, how does this code works:

As excel has multiple pages, SQL has multiple tables in a database. Thus, after knowing which database we are working on we need to retrieve the relevant tables and columns.

Example: We have the following database

Now, If we want 7,8,9 . Then, we will write:

SELECT C3 FROM Table 3

Result

Now if we want to select multiple columns than we specify all the column by using comma “,”.

For 4,5,6 and 7,8,9 from Table 3 we will write the code:

CODE: SELECT C2,C3 FROM Table 3

Result

If we want all the columns of the table then we use asterik “*”

For 1,2,3 and 4,5,6 and 7,8,9 from Table 3 we will use:

Code: SELECT * FROM Table 3

Result

Generally, we do not use * unless we want the whole table as it increases traffic and can slow down your results.

Try this yourself on SQL dvdrental database:

Retrieve the First name and last name from table actor

Retrieve all columns of table actor 

Credits: The concepts and materials are taken from the Udemy course:The complete SQL Bootcamp 2022: Go from Zero to Hero

Check out the other parts in the SQL series:

Previous: Why do we need Structured Query Language (SQL)? SQL PART 1