Synonyms in SQL Server

Synonyms in SQL Server

In SQL Server, synonyms provide an alternative name for a database object. This can be very useful for simplifying code and providing a layer of abstraction. Here's a breakdown of how they work and why they're used:

What are Synonyms?

·???????? A synonym is essentially an alias. It allows you to refer to a database object (like a table, view, stored procedure, or function) by a different name.

·???????? This can be particularly helpful when:

• Objects are renamed or moved.
• You want to simplify complex object names.
• You need to access objects in different databases.

Key Benefits:

·???????? Abstraction:

·???????? Synonyms shield applications from changes to the underlying object's name or location. If the original object changes, you only need to update the synonym, not every piece of code that uses it.

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·???????? Simplified Code:

·???????? They can make your SQL code more readable by using shorter, more intuitive names.

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·???????? Cross-Database Access:

·???????? Synonyms can simplify accessing objects in other databases on the same SQL Server instance.

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·???????? Security Management:

·???????? Users can be granted access to the synonym without direct access to the base object.

How to Use Synonyms:

·???????? Creating a Synonym:

·???????? You use the?CREATE SYNONYM?statement.

·???????? Here's the basic syntax:

CREATE?SYNONYM [schema_name].[synonym_name]?FOR?[server_name].[database_name].[schema_name].[object_name];

??????????????????????????????CREATE?SYNONYM Emp?FOR?HumanResources.Employees;

·???????? Using a Synonym:

·???????? Once created, you can use the synonym just like the original object name in your SQL queries.

???????????????????????????????Select * from?Emp;

·???????? Dropping Synonym:

·???????? We can drop the synonyms. Dropping a synonym?does not?affect the base object

DROP?SYNONYM?Emp;

·???????? Using Synonyms for Cross-Database Queries?:

·???????? If you have a table in?DatabaseA, you can create a synonym in?DatabaseB?to reference it

USE DatabaseB;

CREATE?SYNONYM OrdersSynonym?FOR?DatabaseA.dbo.Orders;

SELECT?*?FROM?OrdersSynonym;

Important Considerations:

·???????? Scope:

·???????? Synonyms are scoped to the database in which they are created.

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·???????? Limitations:

·???????? There are some limitations on the types of objects (Indexing, Full-Text Search, or Triggers)?that can be referenced by synonyms.

·???????? Synonyms cannot be used in DDL statements.

·???????? They?do not support dependencies, meaning they won't show up in dependency reports.

·???????? If the base object is?dropped or renamed, the synonym will break.

In essence:

Synonyms are a valuable tool in SQL Server for improving code maintainability and simplifying database access. They provide a layer of abstraction that can make your database applications more robust and easier to manage.

?https://handbookofsuresh.blogspot.com/2025/02/synonyms-in-sql-server.html

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