How to use the intersect function in Oracle?

In Oracle databases, the INTERSECT function is used to return the intersection of two or more queries, which means it returns the rows that appear in all query results simultaneously. Its basic syntax is as follows:

SELECT column1, column2, ...
FROM table1
INTERSECT
SELECT column1, column2, ...
FROM table2;

The INTERSECT keyword is used to combine the results of two or more SELECT statements and return the rows that appear in all result sets simultaneously. It is important to note that each SELECT statement must have the same number of columns and columns of the same data type.

Here is a simple example demonstrating how to use the INTERSECT function to find rows that exist in both tables at the same time:

SELECT employee_id, first_name, last_name
FROM employees
INTERSECT
SELECT employee_id, first_name, last_name
FROM temp_employees;

This will return rows containing employee_id, first_name, and last_name columns that exist in both the employees table and the temp_employees table.