Model Answer

The following SQL DDL statements create the Books table:

CREATE TABLE Books (
BookID INT PRIMARY KEY AUTO_INCREMENT,
Title VARCHAR(255),
Author VARCHAR(100),
PublicationYear INT,
Genre VARCHAR(50)
);

SQL is the industry standard for DDL and DML due to several key benefits:

• Portability: SQL is a defined standard (ANSI/ISO SQL) which means that applications written using SQL can be used on different database management systems (DBMS) like MySQL, PostgreSQL, Oracle, and SQL Server with minimal modification. This avoids vendor lock-in.
• Ease of Learning: The SQL syntax is relatively consistent across different DBMS, making it easier for developers to learn and switch between systems.
• Powerful and Expressive: SQL provides a comprehensive set of commands for defining, manipulating, and querying data. It supports complex operations like joins, aggregations, and subqueries.
• Wide Support: Virtually all major DBMS vendors support SQL, ensuring a large community of developers and readily available resources.
• Standardized Semantics: The SQL standard defines the meaning of SQL commands, reducing ambiguity and improving interoperability.

A standardized approach to DDL and DML ensures that database operations are performed consistently and predictably, regardless of the underlying DBMS. This simplifies database administration, development, and maintenance.

SQL plays a fundamental role in both Data Definition (DDL) and Data Manipulation (DML) operations within a database system.

Data Definition Language (DDL): DDL commands are used to define and manage the structure of the database. Examples include:

• CREATE TABLE: Creates a new table in the database.

  CREATE TABLE Employees (
  EmployeeID INT PRIMARY KEY,
  FirstName VARCHAR(255),
  LastName VARCHAR(255),
  Salary DECIMAL(10,2)
  );
  

• ALTER TABLE: Modifies the structure of an existing table (e.g., adding a column).
• DROP TABLE: Deletes a table from the database.
• CREATE INDEX: Creates an index on a table to speed up data retrieval.

Data Manipulation Language (DML): DML commands are used to manipulate the data stored within the database. Examples include:

• SELECT: Retrieves data from one or more tables.

  SELECT FirstName, LastName FROM Employees WHERE Salary > 50000;

• INSERT: Adds new data into a table.
• UPDATE: Modifies existing data in a table.
• DELETE: Removes data from a table.

The standardization of SQL facilitates database management by providing a common language for interacting with databases. This allows database administrators and developers to work with different DBMS systems without needing to learn separate languages for each. It simplifies tasks such as data migration, backup and recovery, and query optimization.