WordPress SQL Query to retrieve data

Can anyone provide me the Wordpress SQL queries to retrieve data from the table i have created in my database, but before executing that i need to know how to write the code for the WordPress SQL Query does it require any special editor to write it, could we make changes to the already existing code.

WordPress is a state-of-the-art semantic personal publishing platform with a focus on aesthetics, web standards, and usability. Simply enter your SQL query and click “Execute SQL”. If it’s a select, describe, show, or explain, an HTML table will be returned with your results.To execute an insert, update, delete, or alter, but after that, your fate is in your own hands. If it’s any other command that modifies data or structure, you’ll get a message about the number of rows affected.

I will suggest you to follow the steps given below this will help you to download the SQL executioner that will execute the SQL query.

1. Download wp-sql-executioner-1.0.zip (v1.0)
2. Unzip the file and upload wp-sql-executioner.php to your plugins directory:
   /path/to/wordpress/wp-content/plugins
3. Activate the plugin (don’t forget!)
4. Goto Manage > SQL Executioner

Following are the 5 wordpress SQL Query that are very important from the retrieving data from the database.

• SELECT * FROM wp_users WHERE user_login = ”
  
• SELECT post_date, post_name FROM wp_posts WHERE ID = 0
  
• SELECT option_name, option_value FROM wp_options
  
• SELECT * FROM wp_users
  
• SELECT * FROM wp_categories WHERE 0=0