Difference Between Alias and Synonym
Even though the alias and synonym in SQL have some similarities, the alias and synonym have different purposes and usages. For a better understanding, we can see the list of differences between them below:
|
Alias |
Synonym |
|---|---|
|
To define an alias in SQL, we use the keyword AS. |
To define a synonym in SQL, we use the keyword SYNONYM. |
|
The keyword AS is optional, which means we can skip it. |
The keyword SYNONYM is mandatory, which means we cannot skip it. |
|
Alias is not a database object type. |
A synonym is a database object type. |
|
An alias can be used only for views, tables, or columns of a table. |
Synonym can be used for views, tables, triggers, sequences, etc. |
|
The alternative name created by using an alias is temporary |
The alternative name created by using a synonym is permanent. |
|
Alias is valid inside the query where it is being used. |
Synonym are valid inside the schema or the database. |
|
Alias is useful when column names are lengthy, unreadable, or meaningless. |
Synonym are useful when object names are lengthy and confusing. |
Difference Between Alias and Synonym in SQL
In SQL, two keywords are used to create an alternative name which are alias and synonym. Although both of these have similar functions, each of these keywords has its purpose. This means that the Alias has different usage from Synonym and vice versa.
This article aims to clarify the differences between the alias and the synonym and guide on when and how to use each effectively.