Note FOR JOINS

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INNER VS OUTER JOIN

WE have to tables " Product table " And "Category Table"

We want To make Joins Between Them

But Their Is many Diffrents ways To join :

JOIN

RIGHT OUTER JOIN

LEFT OUTER JOIN

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AS you see prd and cty in the of each line that we did it just f the next we do need to type all the line on commande so prd is a shortcut for AdventureWorks2014.SimpleOrders.Product

"THE JOIN IS A INNER JOIN" AS you see prd and cty in the of each line that we did it just f the next we do need to type all the line on commande so prd is a shortcut for AdventureWorks2014.SimpleOrders.Product And cty is a shortcut for AdventureWorks2014.SimpleOrders.Category

So we just Display a list of the product and theire respective category

But if we want to display all category we need to diplay all from right or left Side

Let's see RIGHT OUTER JOIN

AS You see we force to display all rows in Category NAME

Let's See For Left OUTER JOIN

SELF JOIN

We have category and the parent category

So we want to joint Category With Parent category

USING "cty.parent.category=pty.category"

N.B --- TO get ALL GAtogreys EVEN WITHOUT A Parent Outer Join IS needed

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