What is database Comments?
Comments are the lines that are non-executable in programming languages or SQL. Humans or database administrators can easily understand the comments but compiler not understands these statements. Comments in python language are the way to increase the reliability of the code for a database administrator. Comments will very helpful for future developers, they can easily understand the work using comments on it.
How to Comments in SQL?
SQL provides multiple ways to add comments in your database or tables and want to add constraints in that column. In SQL we can add single line comments and multiple line comments. Single line comments mean you are commenting only one line, but in multiline comments means commenting on or more lines in the same block.
Single-Line Comments in SQL
In SQL we “ — ” operators for single-line comments.
But some versions of SQL and almost all DBMS ( Database Management Systems ) provide another operator for commenting a single line, with number sign operator “ = ”.
# Comments goes here :
Multiline Comments in SQL
SQL also provides a way to comment on multiple lines in the same block. The syntax for multiple lines is given below,
Author: Database name etc.
How to Comment in SQL Shortcuts
Commands for commenting one or multiple lines.
Ctrl + K: Select the one or multiple lines and press this command the selected paragraph will be a comment.
Ctrl + C: it also works same as above Select the one or multiple lines and presses this command.
Commands for uncommenting one or multiple lines.
For Uncommenting again select one or more lines and press these command.
Ctrl + K, and Ctrl + C
After press one of these commands, your text will be uncommented.
Example of Comments in SQL
Below statements contains many singles as well as multiline comments.
SELECT last_name, salary + NVL(commission_pct, 0),
job_id , e.department_id
Select all employees whose compensation is
greater than that of Pataballa.
FROM employees e, departments d
/* The DEPARTMENTS table is used to get the department name. */
WHERE e.department_id = d.department_id
AND salary + NVL ( commission_pct , 0 ) > /* Subquery: */
( SELECT salary + NVL ( commission_pct , 0 )
/* total compensation is salar + commission_pct */
WHERE last_name = ‘ Pataballa ‘ ) ;
SELECT last_name, — select the name
salary + NVL ( commission_pct , 0 ) , — total compensation
job_id , — job
e.department_id — and department
FROM employees e , — of all employees
WHERE e.department_id = d.department_id
AND salary + NVL ( commission_pct , 0) > — whose compensation
— is greater than
( SELECT salary + NVL ( commission_pct , 0 ) — the compensation
WHERE last_name = ‘ Pataballa ‘ ) — of Pataballa.
Can you comment out in SQL?
What does /* mean in SQL?
How do I comment out code in SQL Server?
How do I comment out a single line in MySQL?
How do I comment in Oracle SQL?
- Begin the comment with a slash and an asterisk (/*). Proceed with the text of the comment. This text can span multiple lines.
- Begin the comment with — (two hyphens). Proceed with the text of the comment. This text cannot extend to a new line.
How do you comment in SQL access?
How do you comment in Microsoft Access?
How do you comment out code in access?
- Select the lines to comment.
- On the Toolbar click or the Code VBA menu select Comment » Comment Lines ( Alt-CMC )
How do you comment in Visual Basic?
How do I comment in a macro?
- First, click on the line where you want to insert the comment.
- After that, type an APOSTROPHE using your keyboard key.
- Next, type the comment that you want to add to the code.
- In the end, hit enter to move to the new line and the comment will turn green.
How do you comment out text in VBA?
How do you comment a section in VBA?
How do I comment multiple lines in a macro?
Commenting a block of code in VBA
- Go to View-Toolbars-Customise.
- Select the Command tab.
- Select the Edit Category on the left.
- Drag the “Comment Block” and “Uncomment Block” icons onto your toolbar.