Introduction to SQL: Module 3

 

 INTRODUCTION TO SQL: Module 3
Data Definition Language:

Database structure is defined and maintained using Data Definition Language (DDL), a subset of SQL (Structured Query Language). Using DDL, database objects such as tables, indexes, and constraints can be created, changed, and destroyed.

You can create and modify tables, indexes, and other database objects using the DDL statements' CREATE, ALTER, and DROP commands. These statements outline the structure of a database, describing data types, relationships, and constraints to protect data integrity.

Among the DDL statements are the following:

The database's CREATE TABLE statement is used to create new tables. The table's columns are described together with their data types and any column limitations.

Changes to a table's structure can be made using the ALTER TABLE statement. It can be used to change data types, add or remove columns from tables, and create limitations.

Use the statement "DROP TABLE" to eliminate a table from the database.

DDL is an essential part of database management since it makes it possible to construct and modify the underlying database structure.

Interactive Data Manipulation Language:

Users can interactively modify and query data in a database thanks to the Interactive Data Manipulation Language (IDML), a computer language. IDML is designed to be user-friendly and doesn't need any programming or database management expertise.

In a database management system (DBMS), IDML is frequently used to manage tasks including data querying, record updating, and report preparation. End users typically use it when they need to extract specific data from a database or perform basic data manipulation activities.

Data Control Language (DCL), which is used to control database access, and Data Definition Language (DDL), which is used to design a database's structure, are different from IDML.

Two examples of IDML include SQL (Structured Query Language), which is frequently used for relational databases, and NoSQL, a more recent IDML used for non-relational databases.

For data analysts, database administrators, and other professionals who frequently work with data, IDML is a useful tool. Its simplicity and adaptability make it a great tool for extracting insights from data and producing reports.

Embedded Data Manipulation Language:

A computer language called Embedded Data Manipulation Language (EDML) enables users to alter data while still using another programming language like C, Java, or Python. Developers can integrate database operations directly into their programs by using the programming language EDML to execute SQL commands within a host computer language.

Applications that require real-time data processing or frequent database connections commonly employ EDML. For instance, an e-commerce website might use EDML to retrieve product details from a database and present them to customers in real time.

The most common kind of EDML is SQL embedded in a computer language. In this case, SQL statements are runtime-embedded within the host programming language's source code. The host programming language offers more advanced data processing and manipulation capabilities, whereas SQL is used to connect to the database.

Because it allows programmers to design database-driven applications using just one programming language, EDML is significant. This reduces the complexity of the application and makes it simpler to maintain. Also, EDML can speed things up by reducing the amount of data that needs to be transferred between the database and the application.