Introduction to Database Management

  What is XML ? ML (Extensible Markup Language) is a markup language similar to  HTML , but without predefined tags to use. Instead, you define your own tags designed specifically for your needs. This is a powerful way to store data in a format that can be stored, searched, and shared. Most importantly, since the fundamental format of XML is standardized, if you share or transmit XML across systems or platforms, either locally or over the internet, the recipient can still parse the data due to the standardized XML syntax. XML VS. HTML: WHAT’S THE DIFFERENCE? XML is a markup language used to store, transport and exchange data.  HTML  is a markup language used to create web pages. XML focuses on storing data. HTML displays data. XML uses tags to describe the data, but the tags are defined by the user. HTML has predefined tags. JSON JSON (JavaScript Object Notation)  is a lightweight format for storing and transmitting data. It’s commonly used in web applications f...

 WHAT IS SQL? SQL (Structured Query Language)  is a standard language used for  storing, manipulating, and retrieving data  in databases. It provides a consistent way to interact with various database management systems (DBMS) such as  MySQL ,  SQL Server ,  Oracle , and more. Here are some key points about SQL: Data Manipulation : SQL allows you to perform various operations on data: Querying : Retrieving specific data from tables using the  SELECT  statement. Inserting : Adding new records into tables using the  INSERT INTO  statement. Updating : Modifying existing records using the  UPDATE  statement. Deleting : Removing records from tables using the  DELETE FROM  statement. Data Definition : SQL includes commands for defining and modifying the  structure  of database objects: Creating Tables : Using the  CREATE TABLE  statement. Altering Tables : Modifying existing table structures with...

  DDL is a standardized language with commands to define the storage groups (stogroups), different structures and objects in a database. DDL statements create, modify and remove database objects, such as tables, indexes and stogroups. DDL is also used in a generic sense to refer to any language that describes data. DDL includes Structured Query Language ( SQL)  statements to create and drop databases, aliases, locations, indexes, tables and sequences. It also includes statements to alter these objects and impose or drop certain constraints on tables, such as the following: UNIQUE PRIMARY FOREIGN KEY CHECK The  CREATE  group of DDL commands includes the following: CREATE DATABASE  defines a logical database under the active location root  directory . The database normally consists of a subdirectory of the same name that holds the physical table and index files. Users can use stogroups to implicitly specify different storage directories for individual databas...