What Cant You Name Sql Columns

SQL Programming

When it comes to naming SQL columns, there are certain restrictions that you need to keep in mind. As a database enthusiast, I have encountered my fair share of naming challenges. In this article, I will delve deep into the intricacies of naming SQL columns and discuss what you can and cannot name them.

SQL Column Naming Basics

Before we dive into the restrictions, let’s first understand the basics of SQL column naming. In most database management systems, the following rules generally apply:

  1. Column names must start with a letter and can be followed by letters, digits, or underscores.
  2. Column names are case-insensitive, meaning “Name” and “name” would be considered the same.
  3. Column names can be up to a certain length, usually limited to around 128 characters. It’s always a good practice to keep them concise and descriptive.

Reserved Keywords

One of the first things you need to be aware of when naming SQL columns is the presence of reserved keywords. Reserved keywords are words that SQL uses for specific purposes and cannot be used as column names. These keywords vary depending on the specific database management system you are using.

For example, in MySQL, “SELECT”, “INSERT”, and “UPDATE” are reserved keywords. Attempting to name a column with one of these keywords would result in an error. To avoid conflicts and confusion, it’s best to steer clear of using reserved keywords as column names.

Avoiding Ambiguous Names

Another aspect to consider when naming SQL columns is the importance of avoiding ambiguous names. Column names should be descriptive and meaningful, reflecting the data they represent. It’s essential to choose names that accurately convey the purpose and content of the column.

Imagine you have a table that stores customer information, and you name one of the columns “Data.” This name is extremely vague and doesn’t provide any insight into what type of data the column contains. Instead, opt for more specific and descriptive names like “CustomerName” or “CustomerAddress” to ensure clarity and enhance maintainability.

Special Characters

While SQL allows the use of underscores in column names, it’s generally recommended to avoid special characters and spaces. Special characters and spaces can lead to complications, especially when writing SQL queries or accessing the columns programmatically.

For example, let’s say you name a column “Order Date”. Accessing this column in a SQL query would require backticks or double quotes to escape the space, making the code less readable and more prone to errors. It’s best to stick to alphanumeric characters and underscores for simplicity and consistency.


Naming SQL columns requires careful consideration and adherence to certain guidelines. Avoiding reserved keywords, choosing descriptive names, and steering clear of special characters are essential steps in ensuring the clarity and maintainability of your database.

As a database enthusiast, I have come to appreciate the importance of well-named columns. By following these best practices, you can create databases that are easier to work with, comprehend, and maintain. Happy naming!