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Asked: 2024-09-27T03:41:30+05:30 In:

how to add a comment in sql

Hi there! I’m currently working on a SQL project, and I’ve hit a bit of a snag regarding comments in my SQL code. I know that adding comments is essential for making the code more readable and understandable for myself and others who might look at it later, but I’m not quite sure how to do it correctly.

I’ve come across different types of comments in programming, like single-line comments and multi-line comments, but I’m confused about how to implement these in SQL specifically. For instance, how do I write a comment that only occupies one line? And if I want to add a longer explanation that spans several lines, what’s the best way to do that without causing any syntax errors?

I’ve seen snippets of SQL code where comments seem to interrupt the flow of the queries, and I’m worried that I might accidentally break something if I don’t do it right. Could someone please clarify how to effectively add comments in SQL? Also, are there any best practices or guidelines I should follow to make sure my code remains clean and maintainable? Thanks in advance for the help!

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    2 Answers

    1. So, like, if you wanna add a comment in SQL, it’s pretty simple, I think. 🤔 You just kinda do it like this: 

      
        -- This is a single line comment
        SELECT * FROM my_table; -- This part gets a lot of data
        
        /* 
           And if you wanna do a multi-line comment, 
           just wrap it in these cool stars and slashes. 
           Super helpful for explaining stuff in your code!
        */
        SELECT * FROM another_table;

      Just remember, comments are like little notes for you (or anyone else) to understand what’s going on later. They won’t mess up your queries or anything. So, yeah, comment away!

    2. In SQL, comments can be included in the code to enhance readability and provide explanations for complex queries. A single-line comment can be initiated using two dashes (`–`), where everything following these dashes on that line will be ignored by the SQL engine. This is particularly useful for brief annotations or to disable a portion of the code temporarily. For example:

      SELECT * FROM employees -- This retrieves all employee records

      For multi-line comments, SQL utilizes a block comment syntax that starts with `/*` and ends with `*/`. This allows you to encapsulate larger blocks of text without affecting the execution of the SQL statements. Such comments are valuable for providing detailed documentation or multi-line descriptions. Here’s an example:

      /* This query retrieves employee records for the Sales department
      including their names, positions, and salaries */
      SELECT name, position, salary FROM employees WHERE department = 'Sales';

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