Learn Alias ​​in SQL


In the previous articles, Taimienphi.vn introduced you to SQL commands, including DELETE, CREATE, RENAME, … and SQL clauses including WHERE, LIKE, IN statements. , …. This article Taimienphi.vn will introduce you more about Alias ​​in SQL.


Alias, also known as aliases in SQL, is used to define columns and tables. Basically Aliases in SQL are created to make the selected columns more readable.

Examples of Alias ​​in SQL

To select the names of all students in the class, the Alias ​​query in SQL looks like this:

Alias ​​for columns in SQL:

SELECT first_name AS Name FROM student_details;

Or:

SELECT first_name Name FROM student_details;

In the above query, the column first_name aliases are provided Name. So when the result is displayed, the column name will display as Name, not first_name.

Output:

alias in sql 2

Alias ​​(alias) for the table:

SELECT s.first_name FROM student_details s;

In the above query, the alias “S“is used to define tables student_details and columns first_name selected from the table.

Some notes with Alias ​​in SQL

Alias ​​in SQL is more useful when:

– There are multiple tables related to a query.

– Functions used in the query

– Column names are large or unreadable.

– Multiple columns are combined together.

https://thuthuat.taimienphi.vn/alias-trong-sql-33277n.aspx
The above is information about Alias ​​in SQL. To learn more about SQL statements, readers can refer to the series of SQL commands or How to deploy SQL Server through PowerShell DSC on Taimienphi.vn page.

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