<-- Chapter 23: SQL Wildcards
Chapter 24
SQL Aliases
SQL Aliases are used to rename a particular table name or column name in a temporary manner. In a SQL statement , any table or column name can be temporary change.
SQL Syntax for Columns :-
SELECT columnname AS columnaliasname
FROM tablename;
SQL Syntax for Tables :-
SELECT columnname(s)
FROM tablename AS tablealiasname;
Lets see an examples from the below table "employees" :-
employee_id |
name |
code |
designation |
salary |
101 |
ABC |
E-101 |
Engineer |
12000 |
102 |
DEF |
E-102 |
Doctor |
8000 |
103 |
GHI |
E-103 |
Software Developer |
8000 |
104 |
JKL |
E-104 |
CEO |
12000 |
105 |
MNO |
E-105 |
Software Developer |
100000 |
Alias TABLE COLUMN SQL syntax :-
SELECT `name` AS [Employee Name], `designation` AS [Employee Designation]
FROM `employees`
Now run the above SQL query, we will see the output below :-
Employee Name |
Employee Designation |
ABC |
Engineer |
DEF |
Doctor |
GHI |
Software Developer |
JKL |
CEO |
MNO |
Software Developer |
Now we can see here, columns "name" and "designation" are renamed temporary to Employee Name and Employee Designation.
Alias TABLE SQL syntax :-
SELECT `emp`.`name`,`emp`.`code`
FROM `employees` AS `emp`
Now run the above SQL query, we will see the output below :-
name |
code |
ABC |
E-101 |
DEF |
E-102 |
GHI |
E-103 |
JKL |
E-104 |
MNO |
E-105 |
Now we can see here, table name "employee" is renamed temporary to "emp" .
Chapter 25: SQL Joins -->
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