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एएस के साथ नाम बदलना
By default, columns in the result have the same name as the source column.
When you select an expression (a calculation, a concatenation, an
aggregate) the default name may look ugly or unclear. With AS you assign
an alias, that is, a name of your choice:
SELECT <colonna_o_espressione> AS <alias>
FROM <tabella>;The keyword AS is optional (salary salary_eur works too), but writing it
makes the query more readable. If the alias contains spaces or significant
uppercase letters, wrap it in double quotes: AS "Annual Salary".
Examples
-- Rinomina semplice (in inglese per convenzione):
SELECT first_name AS name,
last_name AS surname
FROM employees;
-- Alias su un'espressione calcolata:
SELECT first_name,
last_name,
salary * 13 AS annual_pay
FROM employees;Try it
Extract each employee's last name and salary, renaming the columns to 'last' and 'salary_eur'.
संकेत दिखाएँ
The keyword is AS: SELECT column AS new_name.
3 प्रयासों के बाद समाधान उपलब्ध है
Review exercise
Extract first and last name concatenated into a single column called 'full_name'. Use the || operator to concatenate and put a space between the two.
संकेत दिखाएँ
In PostgreSQL string concatenation is done with ||, and then the alias with AS.
3 प्रयासों के बाद समाधान उपलब्ध है