July 20th, 2023
Welcome back to our SQL blog series! In the last post, we covered how to create a database and table using SQL, and how to insert data into a table using the INSERT INTO command. In this post, we will cover how to retrieve data from a table using the SELECT command.
Retrieving Data from a Table
To retrieve data from a table using SQL, you can use the SELECT command. Here's an example:
SELECT * FROM mytable;
This command selects all columns and rows from the "mytable" table. The asterisk (*) represents all columns in the table. You can also select specific columns by listing them after the SELECT keyword. Here's an example:
SELECT id, name FROM mytable;
This command selects only the "id" and "name" columns from the "mytable" table.
Filtering Data
You can also filter the data retrieved from a table using the WHERE clause. Here's an example:
SELECT * FROM mytable WHERE age > 18;
This command selects all columns and rows from the "mytable" table where the "age" column is greater than 18.
Sorting Data
You can also sort the data retrieved from a table using the ORDER BY clause. Here's an example:
SELECT * FROM mytable ORDER BY name ASC;
This command selects all columns and rows from the "mytable" table and sorts them in ascending order by the "name" column.
Limiting Data
You can limit the data retrieved from a table using the LIMIT clause. Here's an example:
SELECT * FROM mytable LIMIT 5;
This command selects the first 5 rows from the "mytable" table.
Conclusion
In this post, we covered how to retrieve data from a table using the SELECT command. We also covered how to filter, sort, and limit the data retrieved from a table using the WHERE, ORDER BY, and LIMIT clauses. In the next post, we will cover how to update data in a table using the UPDATE command. Stay tuned!