What is ANSI SQL?

ANSI SQL (American National Standards Institute Structured Query Language) is a standardized version of SQL (Structured Query Language) designed to ensure consistency and interoperability across different database systems. SQL is the language used for managing and manipulating relational databases, and ANSI SQL defines a common set of guidelines and syntax that all compliant databases should follow.

This article explores the concept of ANSI SQL, its features, and its role in database management.

Table of Contents

1. Getting the Understanding of ANSI SQL
   • 1. Definition and Purpose
   • 2. History of ANSI SQL
2. Key Characteristics of ANSI SQL
   • Data Definition Language (DDL)
   • Data Manipulation Language (DML)
   • Data Query Language (DQL)
   • Data Control Language (DCL)
3. Pros of ANSI SQL
   • Cross-Platform Compatibility
   • Standardization and Portability
   • Improved Collaboration
4. Cons of ANSI SQL
   • Vendor-Specific Extensions
   • Missing Advanced Features
5. ANSI SQL vs. Vendor-Specific SQL
6. Conclusion
7. FAQs

1. Getting the Understanding of ANSI SQL

Definition and Purpose

ANSI SQL is a set of standards developed by the American National Standards Institute, ANSI, so that SQL implementations developed by different database systems follow a common structure and syntax. This standard helps maintain consistency and simplify database portability and integration.

History of ANSI SQL

The first SQL standard was introduced in 1986 by ANSI; however, years later, subsequent versions and changes included SQL-89, SQL-92, SQL:1999, and SQL:2016. They were introduced mainly to enhance added features in SQL, considering database requirements are subject to change as time passes by.

2. Key Characteristics of ANSI SQL

Data Definition Language (DDL)

DDL permits a user to create or modify a structure of databases. The DDL commands often include:

CREATE TABLE employees (

    id INT PRIMARY KEY,

    name VARCHAR(50),

    salary DECIMAL(10, 2)

);

ALTER TABLE employees ADD COLUMN department VARCHAR(30);

DROP TABLE employees;

Data Manipulation Language (DML)

DML is used to manipulate data within tables. Some of the most common DML commands are as follows: we have considered the employee table for performing our task.

1. INSERT INTO employees (id, name, salary) VALUES (1, ‘John Doe’, 50000);
   1. This command is for inserting a record in a specified table.

2. UPDATE employees SET salary = 55000 WHERE id = 1;
   1. This is for updating an already existing record.

3. DELETE FROM employees WHERE id = 1;
   1. This is for deleting the records provided a specific condition.

Data Query Language (DQL)

DQL is primarily used to query data. The SELECT statement is the key command:

SELECT name, salary FROM employees WHERE department = 'IT';

Data Control Language (DCL)

DCL manages access control and permissions within the database. Some common DCL commands are:

1. GRANT SELECT, INSERT ON employees TO user123;
2. REVOKE INSERT ON employees FROM user123;

Both the command methods above are trying to provide either a particular access to the user or they are revoking the access for the user.

3. Advantages of ANSI SQL

Cross-Platform Compatibility

ANSI SQL ensures queries that are implemented on one system may be directly implemented on the other if both have been designed using the standard.

Standardization and Portability

It is simpler to switch and switch between several different database systems by having only one standard; hence learning curves may decrease.

Improved Collaboration

With the same rules applied, both developers and the administrators of database may work perfectly with each other.

4. Limitations of ANSI SQL

Vendor-Specific Extensions

While ANSI SQL provides a standard, most database vendors introduce proprietary extensions for advanced features, which reduces full cross-platform compatibility.

Missing Advanced Features

Some modern database requirements, such as JSON manipulation or full-text search, may not be fully covered by ANSI SQL standards.

Some of the most modern database requirement

5. ANSI SQL vs. Vendor-Specific SQL

ANSI SQL

• Follows the standard syntax defined by ANSI.
• Ensures maximum compatibility across databases.
• Limited to core features of SQL.

Vendor-Specific SQL

• Database-specific enhancements such as stored procedures, indexing options, or advanced data types are included.
• It may provide performance optimization for specific use cases.
• Reduces portability between databases.

Example Comparison:
ANSI SQL:

SELECT name FROM employees WHERE salary > 50000;

Vendor-Specific SQL (PostgreSQL):

SELECT name FROM employees WHERE salary > 50000 AND name ~ '^J';

6. Conclusion

ANSI SQL is very important in providing a standardized framework for database management, allowing developers to write portable and consistent queries. Although it forms the basis, most real-world applications use vendor-specific extensions for more advanced capabilities. Understanding ANSI SQL is important for building a solid foundation in database management, ensuring cross-platform compatibility, and maintaining best practices in SQL development.

FAQs