Original subtitles

0 To practice on joins will be creating a separate data set of two tables, let us see how to create 1

these two tables. 2

The first table will be from the sales table, and it will contain only those records where ship date 3

lies between 1st January 2015 and 21st December 2015. 4

So this table will be named as sales_2015 as this sales of year 2015. The second table 5

we are creating is of customers whose ages between 20 and 60. 6

The name of this table will be customer_20_60, and it will be part of the customer table were 7

aged between 20 and 60. For the first table 8

The count of rows will be 2131. This you can check by running this check query. 9

And the number of distinct customers were purchasing in year 2015 is 578, This you can check using this second count 10

query in our customer table where customers are aged between 20 and 60, the count of customers is 597. 11

Some of the customers will be presenting both the tables. 12

Some will be present in only sales table and not in the second customer table. 13

Some will be present in the customer table and not in sales table. 14

This is what we wanted to create so that we can clearly see the difference between all these types of 15

joins, I'm copying these two queries into a text file and attaching it to the resources section of 16

the lecture. 17

You can copy paste these queries to run them. 18

I'm not discussing these queries in depth because we have not discussed subquery, which will be in 19

the later part of this course. 20

Next, we will discuss the inner join.