ALIASES

SQL aliases are used to give a table, or a column in a table, a temporary name. Aliases are often used to make column names more readable. It only exists for the duration of that query and is created with the AS keyword.

• The table_name can also be changed using this as shown in the second code of the below example.

• If you want to name aliases in more than one character and with spaces, square bracket is used or double quotes " "to name it in query

SELECT employee_Id AS ID/ employee_number/ [employee number]
FROM employees;

SELECT employee_id
FROM employees AS workforce 

Concatenate Columns

Concatenating columns in SQL is used to combine multiple column values into a single column value. This is useful for formatting output, creating full names from first and last names, merging address components, or generating unique identifiers.

Example: SELECT CustomerName, CONCAT(Address,', ',PostalCode,', ',City,', ',Country) AS Address
FROM Customers;