1. Select SQL code

   SELECT TOP 3 * FROM CUSTOMER WHERE Customerid ='4de3092d03b742f3b2b88cf6fe0b09d0'

2. Press CTRL+/ (or CMD+/ on Mac) on the keyboard

3. Code will be commented

   --SELECT TOP 3 * --FROM CUSTOMER --WHERE Customerid ='4de3092d03b742f3b2b88cf6fe0b09d0'

4. If you need to uncomment it, you need to mark commented code and press the same keyboard combination CTRL+/ (or CMD+/ on Mac) on the keyboard Code will become uncommented again:

   SELECT TOP 3 * FROM CUSTOMER WHERE Customerid ='4de3092d03b742f3b2b88cf6fe0b09d0'

/*
 SELECT * 
   FROM Academics
   WHERE Academic_id = 1
*/

Same as:

--SELECT * 
   --FROM Academics
   --WHERE Academic_id = 1

If you're working with SSMS, use CTRL + K, then press C for "comment" or U for "uncomment"

If you are using SSMS, you can go to:

Tools - Options - Keyboard (under Environment)

• type in 'comment' in the 'Show Commands containing:"
• select Edit.CommentSelection
• select 'Text Editor' under "Use new shortcut in:"
• Assign a shortcut key that you like (ex: Ctrl + /) --> Assign --> Click Okay

If you want to uncomment then choose Edit.UncommentSelection and follow the step above, but it will need to be assigned to a different key other than Ctrl + /, may be use Ctrl+'

Step to change CommentSelection shortcut key

Documentation for how to comment out queries can be found Here.

But in short, press Ctrl + slash (/) together to toggle between commented/uncommented on highlight lines.

Ctrl + Shift + Slash can be used to comment/uncomment blocks of queries.