Overview of SQL
Structured Query Language (SQL) is a programming language for managing and manipulating relational databases. Here’s an overview of crucial SQL concepts:
- Database: A collection of organized data. It can contain multiple tables, views, stored procedures, and more.
- Table: A structured set of data elements organized in rows and columns. Each column represents a different attribute, and each row is a record.
- Column: Represents a single data item in a table. It defines the type of data that can be stored in that column.
- Row: A record in a table containing data for each column defined in the table.
- Primary key: A unique identifier for each record in a table. It ensures that each row can be uniquely identified.
- Foreign key: A field in a database table that links to the primary key in another table. It establishes a link between the two tables.
- Index: A data structure that improves the speed of data retrieval operations on a database table...