In a complex join, how is the number of tables you wish to join related to the number of WHERE conditions?

When we retrieve data from 2 tables, why do we need to specify a join condition to join the tables in the Where clause?

How do global temporary tables differ from local temporary tables in SQL Server, and when might each be used?

My SQL WORKBENCH **Please note that you may actually use as many tables as you need. You are not limited to use only twotables.Example:SELECT *FROM DEPARTMENTS;SELECT *FROM EMPLOYEES;Now join departments and employees tables.SELECT FIRST_NAME, DEPARTMENT_NAMEFROM EMPLOYEES, DEPARTMENTSWHERE EMPLOYEES.DEPARTMENT_ID = DEPARTMENTS.DEPARTMENT_ID;NOTE: If you omit the join condition, the result will be the Cartesian Product of the two tables. A CartesianProduct joins all rows of the first table with all rows of the second table.That is if the first table has n rows and the second table has m rows, the output will have n*m rows.The following query will produce a Cartesian Product:SELECT FIRST_NAME, DEPARTMENT_NAMEFROM EMPLOYEES, DEPARTMENTS;**When table names are long, qualifying column names might be very time consuming. Usually peopleprefer to use table aliases for this purpose.Example: List the name of all employees who work for 'Purchasing' departmentSELECT E.FIRST_NAME "EMPLOYEE…