Description
DB2 Alias are used to give a temporary and customize and more readable name of a database column while retrieving value with a select query. We can also give a alias to a table. It will help us to shorten the table name while performing join on a tables.
The database DB2 is utilized to deal with a wide assortment of information, for example, the outcome of exploration tests, document assets for organization managers, or the areas and serial quantities of bits of hardware's. At first, IBM had created the product of DB2 for the platforms that are explicit and in the year 1990, Universal Database DB2 Server has been developed, which can keep running on any legitimate working frameworks, for example, Windows,UNIX, and Linux.
Syntax
The DB2 Alias syntax for a column is as follows:
db2 create alias for <table_name>
Table_name => The accurate table name in the database
Alias_name => The operations that can be performed on a column in the table.
Examples
If we want to join 'student_details' table with 'dept' table then we can use aliases to avoid use of long table name.
[c]
SELECT d.dept_num, std. student_name, std. student_id FROM dept d INNER JOIN student_details std ON d.dept_num = std.dept_num;[/c]
Description
Aliases are defined for columns and tables. Basically aliases are created to make the column selected more readable.
Examples
To select the first name of all the employees, the query would be like:
TABLE NAME: EMPLOYEE_NAME
[c]SELECT FIRST_NAME FULL_NAME FROM EMPLOYEE_NAME;[/c]
Output -
| First Name | Last Name |
|---|---|
| Michel | Kors |
| Jhon | Ceana |
| Full Name |
|---|
| Michel |
| Jhon |
Key Points
- DB2 Alias - Used to give a temporary and customise and more readable name of a database column.