Database functions

DATABASE:

A database is a collection of information that is organized so that it can easily be accessed, managed, and updated.

Every table that we are creating will be stored in a database.

so to create , update and delete the database a set of keywords are used.

creation of database:

the database can be created with the keyword 'create database'.

syntax: 'create database database_name';

eg: 'create database customer_database;

deletion of database:

similary, a database can be deleted.

syntax: 'delete database database_name';

eg: delete database customer_database;

the above command will delete the database with name 'customer_database'.

TO ALTER THE FIELDS IN A TABLE:

to add a column to the table:

syntax: alter table table_name

add column data_type;

eg: alter table products

add area varchar(120);

and the above code results in:

and similarly the column in a table can be dropped also:

to delete a column from the table:

syntax: alter table table_name

drop column column_name;

eg: alter table products

drop column area;

and the above code brings the following result:

deletion of table:

the deletion of the table can be achieved by delete keyword.

syntax: delete table table_name;

eg: delete table products;

the keyword delete table products, deleted the table in the name of products and hence there is no, no of records in the table.

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