SQL Formatting Standards: A Beginner’s Guide to 24 Essential Rules

24 SQL Standard Formatting Rules

Code formatting is a very significant concept in any programming language. When we attempt to note the best code for any problem, then that code should be formatted and well-written. There are multiple rules in every programming language for standard formatting. When we obey all the rules of formatting, then that code is straightforward to understand and maintain. There are some rules of standard formatting for SQL language. This writing will give you 24 rules to comprehend the formatting rules for SQL language. So, you can write accurate queries every time for any problem.

Why Do We Need Standard Code Formatting Rules?

When we try to write any query without any standard format, then we may face issues. Let’s see an example based on this.

select  emp.id,emp.name,emp.salary from emp_table 
where (emp.salary > 5000) and (emp.department='IT') 
order by emp.name;
Code language: SQL (Structured Query Language) (sql)

Try to analyze the above query. It is challenging to comprehend what’s the logic we are executing. The overall query is confusing. From this sample query, we can undoubtedly say that we need to obey standard formatting rules while writing.

The flow of the queries is enhanced by proper line spacing, indenting, and capitalizing. There are several reasons and benefits to using correct/standard formatting techniques in our query:

  1. Code is more readable: When any query is written with proper indentation, spacing, casing and format, it is simply easier to read, write and maintain. This kind of code will allow for logical transparency.
  2. Easy to maintain: Queries are challenging to understand sometimes when complicated logic is employed. When we write queries with proper format, then it becomes easy to comprehend the logic. Once the logic is clear, then we can smoothly maintain the code.
  3. Consistent and Optimized queries: Code consistency is very important in any model while getting the results. Consistent codes increase the overall efficiency of the query. Consistent codes deliver the best results with optimized solutions. Optimized codes always perform better under any databases and provide accurate outputs. 
  4. Easy for documentation: These standard formatting techniques help us to write consistent and well-maintained code. Therefore, we can easily document this code/query for a longer period. This is most beneficial for the developers to exchange their works. Documenting different queries for complex/high-level projects is a very important task.

These are a few reasons for writing code/query in the proper standard format. Now, let’s see the rules of formatting.

24 Rules to the SQL Formatting Standard

Let’s see 24 rules of formatting for SQL language.

1. Consistent Indentation in Queries

The indentation is very necessary when we write any query in SQL language. Correct indentations help you to present the query in clear form. The logic of the query is also understandable in a well-indented query. Using consistent indentation is the best practice. The ideal number of spaces is 2 or 4. Also, indent keywords are present within the clauses. 

2. Minimize Line Length

Line length i.e. query length should be limited for each line. For example, if the query is too long, it creates confusion. The flow and readability of the query are clear if we limit the length to 100-120 characters. This practice creates a flow in the query so we can understand logic clearly.  

3. Capitalizing Keywords

When we note table names, and column names in queries and subqueries along with the keywords, then it confuses. But if we capitalize all the keywords, then we can effortlessly differentiate between the column name, table name, etc. We can use lowercase for all other names.

4. Column Alignment in SELECT Statement

If we position all the columns in the SELECT statement then we can smoothly comprehend the logic. Because we always need several columns named from the diverse tables to solve complex problems. A clear insight into column names can ease the complexity of the overall problem. 

5. Meaningful Alias Name

If we are writing any aliases for columns or tables, then that name should hold some meaning. It enhances the readability of queries.

6. Formatting Rules for ‘SELECT’ Statements

As we discussed in rule no. 4, all the columns are aligned under SELECT statements. Therefore, there are some rules like proper indentation inside SELECT statements that should be followed while writing any query/subquery line. The second rule is always to place individual columns on a new line. This clarifies the flow of the query. 

7. Formatting Rules for the ‘FROM’ Clause

All the tables are aligned under the FROM clause. Hence, always note a new table on a separate line. Indentation of the table in a proper way is also essential to comprehend the logic of the FROM clause in a query. 

8. Formatting Rules for the ‘WHERE’ Clause

The WHERE clause consistently creates a lot of confusion because all the complicated conditions are written under this clause. The first rule to diminish the complexity is to break down complex conditions into multiple lines. 

9. Sufficient Amount of Comments

Writing comments in a query will help you to understand the meaning of code. Proper comments always explain a solution without any extra effort. Adding the right comments at the right place is a best practice while writing queries. 

10. Formatting Rules for the ‘JOINs’

When we mention any JOINs in our query to solve problems, first write it in explicit form. For example, INNER JOIN, LEFT JOIN, RIGHT JOIN, etc. It is best practice to use explicit JOINs over implicit JOINs. The implicit JOINs are comma-separated tables. The second rule is not to forget to indent JOINs properly in the query. 

11. Consistent Casing

The consistent casing inside every query eases the complexity of the problem. Just stick to one casing pattern while writing any query. For example, camelCase, PascalCase, snake_case, etc. 

12. Use of Whitespace

Queries are made much more straight by including whitespace generously. Proper flow is achieved when whitespace is put between column names, operators, expressions, keywords and table names.

13. Explicit Declaration of Data Types

When noting any query, the most crucial concern is the declaration of data types. To prevent any confusion, it’s advisable to explicitly display data types when constructing queries. Make sure to always keep this in mind.

14. Formatting Rules for the ‘GROUP BY’ and ‘ORDER BY’ Clauses

The GROUP BY and ORDER BY clauses have a set of formatting rules to be followed when decoding complex problems through queries. It is necessary to mention any table names, column names or anything related on a separate line. The indentation of every line in the query is also crucial.

15. Formatting Subqueries

To properly solve problems within a query, the skilful utilization of subqueries is vital. Inside those subqueries, we employ a variety of column and table names, along with other clauses. Thus, an essential aspect of successfully resolving issues is the appropriate formatting and indentation of the subqueries.

16. Nested Subqueries

The nested subqueries become problematic when we use many subqueries inside the main query. When we write too many subqueries, the general query can be confusing. So, try to limit the number of subqueries present in the main query.

17. Use of Quotation marks

The quotation marks are very important because they describe string literals. You can utilise single or double quotation marks. This sidesteps confusion.

18. Control Over Transaction

Use transactions when it is needed to define and use. The transactions make everything straightforward.

19. Error Handling Rules

When we write any query, we may face some errors while executing it. That’s why we can use TRY-CATCH blocks where it is needed. Also, implement other error-handling techniques while running queries on diverse databases.

20. Formatting Stored Procedure

Proper formatting is necessary for stored procedures, specifically accurate indentation.

21. Correct Use of Indexes

Indexes must be positioned with accuracy in queries to prevent any perplexity.

22. Use ‘SELECT’ implicitly

Implicitly list SELECT statements for only the necessary columns, as this will simplify the overall issue.

23. Consistency of the Query

The logic of the query will be transparent if consistency in formatting, indentation, and style pattern is maintained. Thus, it is important to keep the query consistent.

24. Testing

Deploying a query without testing is doomed to failure. Thus, testing is an essential practice in the formatting process, and should always be the final step.


In this article, the 24 formatting rules for SQL language are mentioned. The formatting rules always play an important role in easing down the complexity of the problems. If we obey the rules properly, then optimized results are obtained. These rules are very simple and easy to follow. Hope you will enjoy this article!