Database

  XML, or Extensible Markup Language, is a markup language used for structuring and organizing data in a hierarchical format. It is widely used for data representation and exchange between different systems and applications. XML utilizes tags to define elements and their relationships, allowing for flexibility and extensibility in data modeling. In an XML document, the data is enclosed within a pair of opening and closing tags. These tags define the structure and content of the data. Here is an example of an XML description: <?xml version="1.0" encoding="UTF-8"?> <bookstore>   <book category="fiction">     <title>Harry Potter and the Philosopher's Stone</title>     <author>J.K. Rowling</author>     <year>1997</year>   </book>   <book category="fiction">     <title>The Great Gatsby</title>     <author>F. Scott Fitzgerald</author> ...

  What is SQL? SQL stands for Structured Query Language. It is a programming language specifically designed for managing and manipulating relational databases. SQL allows users to store, retrieve, modify, and delete data from databases. It is widely used in the field of data management and is the standard language for interacting with relational database management systems (RDBMS). SQL provides a set of commands that enable users to perform various operations on databases. These operations include creating and modifying database schemas, inserting and updating data, querying the database to retrieve specific information, and defining relationships between tables. Some common SQL commands include: SELECT: Used to retrieve data from one or more tables based on specified criteria. INSERT: Used to add new records into a table. UPDATE: Used to modify existing records in a table. DELETE: Used to remove records from a table. CREATE: Used to create a new database, table, or other datab...