- SQL Databases: Use structured query language (SQL), have predefined schemas, are table-based, and are best for complex queries and multi-row transactions.
- NoSQL Databases: Use dynamic schemas, store data as documents, key-value pairs, or graphs, and are ideal for unstructured data and scalability.
A relational database organizes data into tables (rows and columns) with relationships between them. Each row represents a record, and each column holds a specific type of data (attribute).
- Data Integrity: Ensures accurate and consistent data.
- Flexibility: Allows easy querying and modification.
- Security: Provides access control and permissions.
- Relationships: Handles complex relationships between data efficiently.
- Not ideal for unstructured or semi-structured data (e.g., multimedia).
- Scaling is limited (requires vertical scaling).
- Complex queries can become slower with very large datasets.
SQL is used to interact with relational databases. It allows users to create, read, update, and delete data, define schemas, and manage relationships and constraints in a structured and efficient manner.