SQL Tutorial - 10: Creating Tables from Other Tables Video Lecture | Microsoft SQL for Beginners - Database Management

hello guys welcome to my channel this is
the tenth tutorial in this course and in
this tutorial we are going to understand
how we can create tables and SQL using
tables that are already existing in our
database right and what this means is
that as you can see it's possible to
create tables through other tables and
when you're doing this you can select
one two or as many columns as you want
from tables that are already existing
and the statement that we are going to
use to do this is the create table
statement and we've seen the create
table statement in action the last
tutorial it has a very simple syntax and
the syntax is going to be the same for
you know doing this is valid but it's
it's going to have a few more keywords
so you know we have the create and the
table both the keywords at the beginning
and then you have to specify the name
for your new table and then a keyword as
and then another keyword select and then
you have to mention the columns that you
want to sort of pull from the existing
table and then you mention the keyword
from and then finally you mention the
name of the table from which you want
the fields or the columns to be pulled
right and whatever you see in the square
brackets or that is optional so if you
want all that all the columns to be
pulled from the existing table then
although that doesn't make sense you're
just duplicating the table but if you
want to do that then you cannot specify
any column after the Select keyword
right and also the very clause that you
see at the end that's optional too and
we're going to talk about the where
clause later on in this course but for
the time being we are going to see very
simple application of this and we're
going to see how we can create one table
from another so I've got my MySQL
workbench here now and before we do
anything we are going to check out the
structure of the employee table that we
created in the last tutorial and as I
mentioned the last tutorial there are
two ways of doing this
firstly we can see that in the object
browser in the test database I have the
employee table here and if I want to see
the columns that are there in the table
then I can you know click on the drop
down for the employee table and then
click on the drop down for columns and
I can see the four columns that I have
in the table alternatively if I wanted
to use an SQL command to do this then
the command is de SC and I told you that
de SC is the short form for describe and
if you want to type in the entire word
described then you can do that too right
so if I type in describe and then the
name of the table which is employee and
press the control enter key combination
I see that I get the result set and in
the set I see my four columns I see the
data types of my columns and I see where
you know there are any constraints on
the columns or not so if suppose I want
to create another table let's say I want
to call it employee info right or EMP
underscore info something like that and
if I want that table to have just two
columns right the ID column and the name
column and I don't want the DOB column
or the email column to be in that table
then I can use the syntax that we just
discussed in the PowerPoint to you know
do that and the reason why someone would
want to do something as crazy as this is
you know if suppose you got let's say 15
columns in your table and you know all
the information when put together it
just becomes too overwhelming for you
and you just want to you know have you
know little bit of information from that
table so you just want to see few fields
like one or two fields you know in that
case you can you know create another
table and you can you know sort of copy
those fears that interest you in that
table and you can know you know execute
your SQL queries on that table right so
anyway let's see how to create the EMP
underscore info table so I'm going to
type in the keyword create first and
then table and then the name of the
table which I said I am going to name it
EMP underscore info and then the keyword
as and then on the next line SQL by the
way is case insensitive and also vice
whitespace insensitive so you know I can
type in the from SOI I'm supposed to
type in the select keyword here first so
I can type in the select keyword here
right or I can type it on the next line
I just don't want things to shift too
much towards the
the right that's why I'm going to type
in the select keyword on the on the line
number four and then since I just want
the ID column and the name column from
the employee table I'm just going to put
in those column names and of course you
know you have to put in commas between
the columns and then I'll type in the
from keyword and then the name of the
table which is employee employee and
I'll put in the semicolon determinate
the statement when I press the ctrl
enter key combination I see in the
output section that the create table
statement has been processed and if I
click on the refresh button here let me
first collapse some of these and when I
click on the refresh button you see that
now I see two tables in the test
database the EMP underscore info table
and the employ table and if I would you
know describe the EMP underscore info
table and I would see that it just has
two columns the ID column in the name
column right so that's it for now in the
next tutorial we are going to discuss
something interesting again I hope you
guys had fun watching this one and
please subscribe to my channel in case
you haven't already and I'm going to see
you soon