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[Music]
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hello friends welcome back to our
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channel so in today's session we'll go
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with a one command sql command in dbms
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that is a create command
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so create command in sql
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so first of all we'll start with the dm
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ddl command so d d l commands so ddl
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commands we have discussed about these
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things in the previous sessions which is
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nothing but a definition
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which gives the definition right so
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one is a create
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drop
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truncate
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etc etc all these will be the
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data definition language commands so in
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that we will see the create command so
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how what is the syntax for create
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command so in order to use this sql
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commands
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sql commands
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we require one dbms tool
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one dbms2
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so we will select
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mysql as a
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dbms tool to execute the queries
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so why because i mean why to select this
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mysql means it's a open source
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right so we can also select the oracle
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or sql server
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etc right so i will
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choose this mysql as a dbms tool to
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execute the sql queries
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right so how to download this mysql and
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how to install this mysql in our system
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i have recorded the session and i will
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post the
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link in the description section you just
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follow that and you can install download
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and install the mysql
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and then you can execute these queries
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now
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so by if you want to execute this sql
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command so first of all we have to
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create the database the first step we
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need to create a database
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so inside this database
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we have to create
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tables
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we have to create
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tables
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right so all these tables will be stored
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in this particular database
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okay and
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this
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dbms tool this mysql will be having a
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lot of databases
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and inside this table databases will be
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having lot of tables
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inside the databases will be having a
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lot of tables so first we have to create
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a database and then we have to create
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the table into this particular database
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now first of all let us see the syntax
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for creating the database
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okay so here uh mysql we have chosen the
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dbms tool as a mysql it will comes under
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the two different variations one is a
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gui graphical user interface in the
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command line interface
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so what's the difference what is the
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difference so here everything all the
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queries you need not write the queries
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you can simply use a
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selections okay mouse selections and
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mouse moves to execute the queries so
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the query will be automatically
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generated right but here in the command
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line you have to write down the query so
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we will use this command line because we
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have to practice the sql commands by
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writing the queries so that's why we'll
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go with the command line i will show
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everything in the system don't worry
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about that
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so first of all let us see how to create
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a database
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how to create a database so if you log
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into the mysql command line you will get
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a sql prompt
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you will get sql prompt and here you
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need to write down the queries so in
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order to create the database
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create database
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so the syntax is
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create
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database
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followed by
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database name so whatever the name you
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you are going to give so that will be
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given here right database name so one
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database will be created in my in in
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this particular mysql with a given name
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with a given name and one thing just
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remember every query will be terminated
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with a semicolon so that's the most
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important thing
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every query
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so which we have you are going to write
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in this sql prompt
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will be terminated
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using
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semicolon using semicolon so after end
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of the query you have to place the
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semicolon so if you are not placing the
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semicolon if you press enter
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automatically the query will be
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continued with the next line so here the
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query can be written in a multiple lines
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so the query is not restricted to write
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in a single line so the query can be
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written in a multiple line so unless the
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user gives the semicolon the query will
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be keep on going with the new lines
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so once you give the semicolon that
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shows the end of the query so then the
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query will be executed so i will show
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everything in the
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command line of mysql okay so the syntax
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for creating the database is create a
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database database name and semicolon so
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if you want to check how many databases
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and what are the databases available in
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this particular
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mysql the command
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so the next one is displaying
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databases
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it
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mysql
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so that is the command is
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show
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databases
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show
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databases so automatically it will give
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a table of
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databases
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so it will give a table of databases
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so once you execute this one it will
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give that this one
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okay now
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we have created a database and
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we have seen whether the database has
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been created in the mysql or not so if
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if the database was created here so that
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will be available in this particular
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list
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right so once it was done our next step
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is we have to create a table
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so in order to create a table that table
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should be created in a particular
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database so first we have to enter into
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the database and in that particular
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database we have to write on the
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tables i mean we have to create the
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tables and we can execute the queries so
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how to
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enter into that particular database how
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to enter into particular database so
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see i will show you
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so it will show the result here with a
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list of databases
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so
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entering
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into database
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sorry
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entering into the database the query is
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sql
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use
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database name
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use database
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name so automatically we will be
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entering into that particular database
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now after this one we'll get a command
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that database changed
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we'll get the statement
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simply here the database
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changed
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so if you got this statement that
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implies we are entering into that
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particular database and we are going to
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use this particular database so in that
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particular database we are going to
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write the tables so whatever the tables
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we are creating that will be saved in
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this particular database
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okay whatever the database given here
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so
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once you enter into this particular
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database now we have to create a table
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so whatever the tables we are going to
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create everything will be in this
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particular database name so
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next step how to create a table
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how to create a table
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creating
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table
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so as i have said that the query can be
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written in
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a multiple
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rows okay multiple lines
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so
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sql
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the prompt and here we give the command
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create
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table
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give the table name
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table name
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and open the parenthesis and in the
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table we know that there will be columns
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and rows so we have to give the columns
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that we call it as an attributes so we
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have to define the attributes which
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should be available in this particular
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table
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with the corresponding data types so
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based upon the value we are storing into
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the attribute we have to define the
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particular attribute with the
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corresponding data type so in the
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previous session we have seen the
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different data types right so here
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see
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if you press enter automatically you
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will get one more line
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okay and because here we have not given
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semicolon if you're given semicolon that
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will be treated as a end of the query so
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if you are not giving any semicolon and
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press enter automatically it will go
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with the new line and here you can
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define attribute
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attribute one and corresponding data
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type
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data type comma and again if you press
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enter again it will move with the next
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line
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attribute
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to
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and
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data type
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and if you press enter third line
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so it will be keep on moving unless that
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user enters the semicolon
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data type okay and so on
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so on
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and finally if you use a closed
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parenthesis and
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you use a semicolon then the table will
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be created with the following attributes
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a table will be created with the
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following attributes
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right
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so hope you understood this one so i
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will explain this
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table creation also in the mysql command
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line okay we'll create one table with a
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different attributes and here
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one more thing
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so we can create a table without the
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constraints and with constraints so we
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can give the constraints for this
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particular attributes
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okay in order to avoid the redundancy if
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you
11:02
in order to
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link one table with another table in
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order to give the default values okay so
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there are many constraints so those
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constraints should be given for these
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attributes while creating a table so we
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have not discussed about these
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constraints so far so in this session i
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am just showing how to create a table
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without any constraints here we are not
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giving any constraints this is a simple
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creation of a table okay in the next
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sessions i will explain you about the
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constraints what are the different
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constraints we can give for the
11:33
attributes and then we will see one more
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time how to create a table with a
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particular constraints
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okay i will demonstrate everything with
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an example right so this is how we can
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create the table
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in inside the database
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okay inside a database now
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if you want to
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look at what are the tables available in
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the database
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if you want to look at what are the
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tables available in the database so i
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will execute the same query in the mysql
12:03
command line don't worry so i will show
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everything in a practical
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so
12:08
displaying
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tables
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in database
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in database
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so the query is similar to our databases
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here also we can use
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show
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tables
12:30
so show tables
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short tables
12:34
okay show tables will give a list of
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tables which are available in that
12:40
particular database
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in that particular database it will give
12:44
a complete list okay the queries index
12:47
will be small different there will be a
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light difference with the different dbms
12:50
tools so if you are using some oracle
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if you are using some oracle
12:55
the syntax will be
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select
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star
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from
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tab
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so this is the syntax to
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list out all the tables of particular
13:06
database okay the syntax would be a
13:09
light difference slight difference
13:12
so we are using a mysql in this mysql
13:16
so this is a syntax to create or to list
13:19
out all the tables available in the
13:21
database
13:23
so
13:24
let us see everything the execution of
13:26
uh
13:27
each and every syntax that means how to
13:30
create a table how to create a database
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how to use the database how to show the
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database table databases and how to show
13:37
the tables in the mysql command line
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prompt
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so let us move on to the system and let
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us see the execution of all these
13:44
queries so let's move on to the s mysql
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hello friends so just now we have seen
13:51
the create command in sql right so now
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we'll see the implementation part so how
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we can
13:58
execute the query create so in this
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session we have seen how to create a
14:04
database and how to create a table
14:06
without constraints okay so after this
14:09
session from the next session we'll see
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how to create a table with the
14:13
constraint right so let us see
14:16
first uh here i am using
14:19
the dbms tool mysql to execute the
14:21
queries
14:22
right so in the previous sessions
14:25
already have
14:26
recorded how to download and install the
14:28
mysql so i will post the link in the
14:31
description section so you can just
14:33
follow that and you can install the
14:34
mysql so i have chosen this mysql you
14:37
can use oracle sql server etc etc so i
14:41
why i have preferred this mysql means
14:43
it's an open source so you did not pay
14:46
anything so it will be available in the
14:48
internet so you can download and install
14:50
and you can execute all the queries and
14:52
mysql will be coming in two interfaces i
14:55
mean two different interfaces one is a
14:57
graphical user in the command line so we
14:59
will execute the queries in the command
15:01
line because if you use the
15:04
user interface graphical user interface
15:06
so you did not execute the query
15:08
directly by using the most moves and
15:09
clicks you can directly create a table
15:12
and you can execute the queries but you
15:13
have if you want to learn the queries
15:16
sql queries so if my suggestion is work
15:19
with the command line interface so you
15:21
will be getting these two icons you can
15:23
see mysql workbench and mysql command
15:25
line so
15:27
here you will be getting mysql folder
15:31
so i will show you
15:33
see
15:34
mysql folder in this mysql you will be
15:36
finding all these options so one is a
15:38
command line and mysql workbench so user
15:41
mysql command line so i have already
15:45
taken so it will prompt for the password
15:47
just give the password
15:48
so
15:49
here we'll get the prompt
15:51
okay so the first one if you want to
15:54
clear the screen use the command system
15:56
cls so it will clear the screen
15:59
now
16:00
as we have discussed it just now
16:02
before creating the tables first we have
16:05
to create a database
16:06
so if you want to create a database
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in mysql simply use create
16:13
a database name
16:15
okay create
16:16
database
16:18
database name so i'll give the database
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name as youtube
16:22
okay semicolon it will end the query so
16:25
execute you can get the you will getting
16:28
the command like a query okay one row
16:30
affected now if you want to
16:33
uh look at the databases which are
16:35
available in our mysql
16:37
use the command use
16:39
sir show
16:41
database
16:43
databases
16:45
so these are all the databases available
16:47
in
16:48
mysql okay these are all the database
16:51
available in mysql
16:52
so
16:53
here we have created the database
16:56
youtube so you can find the name here
16:58
here itself
16:59
okay and also
17:02
now we have to create a table inside
17:05
this database so first of all we have to
17:08
select the database in which we want to
17:10
create a table and then we have to enter
17:12
into that particular database and then
17:15
there we have to create a table if you
17:17
want to enter into a particular database
17:19
which we want to select use a command
17:21
use the database name
17:23
so
17:25
so you can you will get the statement
17:27
database changed now we are in the
17:29
youtube database now whatever the tables
17:31
we are going to create everything will
17:33
be saved in this particular youtube so
17:35
in order to
17:37
get the details of the tables available
17:39
in this particular database use the
17:40
command show
17:42
tables
17:43
so you can see empty set that means
17:44
there are no tables till now there are
17:46
no tables right so first we'll create a
17:49
table student okay without any
17:51
constraints so actually we have to
17:53
create a table with a multiple
17:54
constraints so we'll see what are the
17:56
constraints we can see in the next
17:58
session and again we will see the same
18:00
command that means how to create a table
18:02
using those constraints but now in this
18:05
session we'll see how to create a table
18:07
without the constraints so that
18:11
syntax is create table student
18:14
and you can give the query in a multiple
18:17
lines we can write the query in multiple
18:19
lines and here the semicolon is a
18:21
termination of a query and until the
18:24
user gives the semicolon the query will
18:26
be continuously keeps on moving so just
18:29
give enter give the attribute so what is
18:32
the first attribute student id and give
18:34
the corresponding data type what is the
18:36
student id data type that means the
18:38
value which holds the student id is an
18:41
integer so
18:42
declare this one with a integer
18:44
comma the second attribute is the
18:46
student name
18:47
the student name will be the character
18:49
so the data type can be where care and
18:51
do the maximum size of the name it
18:53
should accept so the student name can
18:56
have only the characters 30 characters
18:59
okay not more than 30 characters and the
19:01
third one student branch so which branch
19:04
he or she belongs to the student branch
19:07
is also
19:09
a character so where can offer some 20
19:12
the length of the branch should be not
19:14
more than 20 and the last one is a
19:16
student percentage which is of a real
19:17
number that is a float value
19:20
so float value and close the parenthesis
19:22
and use a semicolon so that the table
19:25
will be created so you can see the query
19:27
okay 0 rows affected
19:29
so a table has been created now now use
19:32
the command show tables to display all
19:35
the tables of this youtube database so
19:38
tables
19:40
see
19:40
there is a table in a youtube database
19:43
that is a student
19:45
so what are the records of a student so
19:48
this is an empty table okay empty table
19:51
so in order to use a in order to list
19:53
out all the records of a student table
19:55
so you have to use a command select star
19:57
from table name so it will display all
19:59
the
20:01
sorry
20:02
select star from student okay table name
20:06
so it's an empty set because we have not
20:08
inserted any rows or records inside the
20:10
table just we have created a table
20:12
now
20:13
if you want to know about the structure
20:15
of this particular table which we call
20:17
it as a schema
20:19
schema of the table right so what are
20:21
the attributes and what is the data
20:22
types given for those attributes use the
20:24
command called the description dsc
20:26
describe
20:28
describe table name so that it will give
20:31
all the field field names okay all the
20:33
attribute names those types data types
20:37
and the constraints what are the
20:38
different constraints given for those
20:40
attributes so actually here we have not
20:42
given any constraint so null value is by
20:45
default so everything it will accept a
20:46
null value and the default value is a
20:49
null value for all the attributes so we
20:51
can set all these things while creating
20:54
a table okay we can set all the
20:56
constraints given for the attributes
20:59
while creating a table so
21:02
we have created a table without any
21:04
constraints without any constraints we
21:06
have created a table
21:07
right so this is how we can create a
21:11
table and a database the create command
21:14
the data definition language command is
21:16
a create the first ddl command is a
21:18
create so for that create we have seen
21:21
the syntax how to create a database and
21:23
how to create that table okay and once
21:26
again i am repeating creating a table
21:28
without constraints without giving the
21:31
constraints but we have to create the
21:33
table by using the constraints so that
21:35
the redundancy will be avoided so that
21:38
will discuss in the further sessions
21:40
right so hope you understood this simple
21:43
create command
21:44
so
21:45
uh if you are having any doubts
21:47
regarding this one feel free to post
21:48
your doubts in the comment section
21:49
definitely i'll try to clarify all your
21:51
doubts and if you're real enjoyed my
21:52
session like my session share my session
21:54
with your friends and don't forget to
21:55
subscribe to our channel thanks for
21:57
watching thank you very much