In SQL, a synonym is an alternative name for a database object. Imagine you have a long and complex table name like customer_transaction_history_2026. Typing it again and again is tiring. So, you create a short name like cust_txn. That short name is called a synonym.
Synonyms are commonly used in large databases to make queries shorter, clearer, and easier to manage. They are helpful for developers, database administrators, and students learning SQL.
This article explains the meaning of synonyms in SQL, their types, syntax, benefits, and examples using popular systems like Oracle Database, Microsoft SQL Server, and MySQL.
What is a Synonym in SQL?
Definition
A SQL synonym is a database object that acts as an alias (alternative name) for another database object such as a table, view, function, or procedure.
It does not store data. It only points to another object.
Why Use Synonyms in SQL?
- To shorten long object names
- To improve readability of queries
- To hide the actual object location
- To simplify database maintenance
- To provide security abstraction
Basic Syntax
The syntax depends on the database system.
1. Synonyms in Oracle Database
In Oracle Database, you can create a synonym like this:
CREATE SYNONYM emp FOR employees;
This creates emp as a synonym for the employees table.
Public Synonym
CREATE PUBLIC SYNONYM emp FOR hr.employees;
Public synonyms are accessible to all users.
2. Synonyms in Microsoft SQL Server
In Microsoft SQL Server, the syntax is:
CREATE SYNONYM emp FOR dbo.employees;
To delete a synonym:
DROP SYNONYM emp;
3. Synonyms in MySQL
In MySQL, there is no direct synonym feature like Oracle or SQL Server.
Instead, developers use:
- Views
- Aliases in queries
Example using alias:
SELECT * FROM employees AS emp;
Types of SQL Synonyms
1. Private Synonym
Visible only to the user who created it.
2. Public Synonym
Accessible to all users in the database.
How Synonyms Work
When you query a synonym:
SELECT * FROM emp;
The database automatically redirects it to:
SELECT * FROM employees;
The synonym acts like a shortcut.
Advantages of SQL Synonyms
- Makes SQL code cleaner
- Reduces typing errors
- Helps when migrating databases
- Allows object renaming without breaking applications
Limitations
- Synonyms do not store data
- If the original object is deleted, the synonym becomes invalid
- Not supported the same way in all database systems
Example Scenario
Suppose a company database has this table:
company_sales_2026_final_report
Instead of writing that long name every time, create:
CREATE SYNONYM sales FOR company_sales_2026_final_report;
Now you can write:
SELECT * FROM sales;
This saves time and improves clarity.
Difference Between Alias and Synonym
| Feature | Alias | Synonym |
| Temporary | Yes | No |
| Stored in database | No | Yes |
| Scope | Query only | Database object |
Alias works only inside a query.
Synonym is a permanent database object.
When Should You Use Synonyms?
Use synonyms when:
- Working in large enterprise systems
- Accessing remote database objects
- Simplifying complex schema names
- Improving maintainability of applications
Conclusion
SQL synonyms are powerful tools that make database management easier and more efficient. They act as alternative names for database objects, improving readability and reducing complexity. While systems like Oracle Database and Microsoft SQL Server fully support synonyms, MySQL uses alternative methods like views and aliases.Learning SQL synonyms helps developers write cleaner queries, manage large systems better, and improve database design skills. Practice creating and using synonyms to strengthen your SQL knowledge.
I’m Zahid Abbas, an educator, researcher, and digital publishing strategist with a passion for linguistics, grammar, and clear communication. As a content creator and SEO specialist, I craft research-driven, reader-focused content that empowers learners and makes knowledge accessible worldwide.
