aliasing in sql code example

Example 1: sql alias

-- SELECT my_col_name AS my_alias FROM my_table;
SELECT sysdate() AS "Current date";   			-- MySQl Alias
SELECT sysdate AS "Current date" FROM dual;   	-- same in Oracle

Example 2: alias in sql

ALIAS command in SQL is the name that 
can be given to any table or a column.
This alias name can be referred in WHERE
clause to identify a particular table or a column.