070 Temporary Tables

SQL

--Way 1
select CustomerEmail, OrderDate 
into #tempOrders
from Orders
where Status = 'Shipped'

select * from #tempOrders

--Way 2
drop table #tempOrders
create table #tempOrders
(    
    CustomerEmail nvarchar(500),
    OrderDate datetime
)

insert into #tempOrders
select CustomerEmail, OrderDate 
from Orders
where Status = 'Shipped'

select * from #tempOrders

RealExamples

Data

-- Create the departments table
CREATE TABLE departments (
  dept_no INT NOT NULL PRIMARY KEY,
  dept_name VARCHAR(100) NOT NULL,
  dept_location VARCHAR(100) NOT NULL
);

-- Insert some test data into the departments table
INSERT INTO departments VALUES
(1, 'Sales', 'Chicago'),
(2, 'Marketing', 'London'),
(3, 'IT', 'Toronto');

-- Create the employees table
CREATE TABLE employees (
  emp_id INT NOT NULL PRIMARY KEY,
  emp_name VARCHAR(100) NOT NULL,
  emp_contact VARCHAR(25),
  salary INT NOT NULL,
  mgr_emp_id INT,
  dept_no INT NOT NULL,
  FOREIGN KEY (mgr_emp_id) REFERENCES employees (emp_id),
  FOREIGN KEY (dept_no) REFERENCES departments (dept_no)
);

-- Insert some test data into the employees table
INSERT INTO employees VALUES
(1, 'Alice', '[email protected]', 5000, NULL, 1),
(2, 'Bob', '[email protected]', 6000, 1, 1),
(3, 'Charlie', '[email protected]', 4000, 2, 2),
(4, 'David', '[email protected]', 5000, NULL, 2),
(5, 'Eve', '[email protected]', 3000, 4, 3),
(6, 'Frank', '[email protected]', 4000, NULL, 3);

Temporary Table

--select * from departments

--select * from employees


select
    d.dept_no, d.dept_name, avg(e.salary) as 'avg_salary'
into #deptavg
from departments d
 join employees e on d.dept_no = e.dept_no
group by d.dept_no, d.dept_name

--select * from #deptavg

select    
    e.emp_name as 'Name',
    e.salary as 'Salary',
    d.dept_name as 'Department',
    d.avg_salary as 'Avg_Salary',
    ISNULL(em.emp_name,'') as 'Manager'
from employees e
    join #deptavg d on d.dept_no = e.dept_no
    left join employees em on e.mgr_emp_id = em.emp_id

drop table #deptavg

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