--BASIC SELECT

SELECT EmployeeID, LastName, FirstName, BirthDate
FROM Employees

-- Returns Error
SELECT EmployeeID, LastName, FirstName, BirthDate

-- With comment
SELECT EmployeeID --, LastName, FirstName, BirthDate
FROM Employees

SELECT *
FROM dbo.Employees

-- Not Case sensitive
SELECT employeeid, LASTNAME
FROM Employees

-- Conventions:

select employeeid, lastname from employees

-- Case and New line:
SELECT employeeid, lastname
FROM Employees

--ALIAS
SELECT EmployeeID AS ID, LastName "Last name", FirstName first_name, BirthDate 
FROM dbo.Employees

-- Quotation marks
SELECT EmployeeID AS ID, LastName last name, FirstName first_name, BirthDate 
FROM dbo.Employees

SELECT EmployeeID ID, LastName "Last name", FirstName first_name, BirthDate 
FROM dbo.Employees

--CONCATENATE
SELECT LastName, FirstName Name 
FROM dbo.Employees

SELECT LastName+FirstName 
FROM dbo.Employees

SELECT LastName+FirstName Name 
FROM dbo.Employees

-- Include literal
SELECT LastName+ ' ' +FirstName Name, EmployeeID  
FROM dbo.Employees

-- Illegal " instead of '
SELECT LastName+ " " +FirstName AS 'Full Name', EmployeeID  
FROM dbo.Employees

-- If I want to include a ' in the string, I need to double it
SELECT LastName+ '''s first name is ' +FirstName Name, EmployeeID  
FROM dbo.Employees


--ARITHMETHMATIC EXPRESSION
SELECT ProductID, ProductName, UnitPrice, UnitPrice*1.1 RAISE
FROM dbo.Products

SELECT ProductName, UnitPrice, (UnitPrice+10)*1.1 RAISE
FROM dbo.Products

-- Order of precedence - *,/ Before +,-

SELECT ProductName, UnitPrice, UnitPrice+10*1.1 No_Sograyim, (UnitPrice+10)*1.1 Sograyim
FROM dbo.Products

--DISTINCT
SELECT CustomerID
FROM dbo.Orders

SELECT DISTINCT CustomerID
FROM dbo.Orders

-- Distinct rows (Instances) - Any distinct combination of the column values
SELECT DISTINCT CustomerID, employeeid
FROM dbo.Orders

SELECT DISTINCT CustomerID, employeeid, orderid
FROM dbo.Orders