SQL stands for Structured Query Language. It is a programming language used for managing and manipulating relational databases.

A database is a structured collection of data that is organized and managed for efficient retrieval and manipulation.

A primary key is a unique identifier for each record in a table. It ensures that each row can be uniquely identified and provides a way to enforce data integrity.

A foreign key is a column or a set of columns in a table that refers to the primary key of another table. It establishes a relationship between the two tables.

SQL databases are relational databases that store data in structured tables, while NoSQL databases are non-relational and store data in a flexible format like key-value pairs or JSON documents.

The WHERE clause is used to filter rows based on a condition before grouping them, while the HAVING clause is used to filter groups based on a condition after the grouping is done.

INNER JOIN returns only the matching rows between two tables, while OUTER JOIN returns all rows from one table and the matching rows from the other table.

ACID stands for Atomicity, Consistency, Isolation, and Durability. These properties ensure that database transactions are reliable, consistent, and maintain data integrity.

Normalization is the process of organizing data in a database to eliminate redundancy and dependency issues. It involves splitting data into multiple tables and defining relationships between them.

A subquery is a query nested within another query. It is used to retrieve data from one or more tables based on the result of another query.

UNION combines the result sets of two or more SELECT statements and removes duplicates, while UNION ALL combines the result sets without removing duplicates.

A stored procedure is a set of SQL statements that are stored in the database and can be executed multiple times. It helps improve performance, code reusability, and security.

A table stores data physically in the database, while a view is a virtual table that is derived from one or more tables or views. Views provide a way to simplify complex queries and restrict access to data.

The GROUP BY clause is used to group rows based on one or more columns. It is often used with aggregate functions like COUNT, SUM, AVG, etc., to perform calculations on grouped data.

The ORDER BY clause is used to sort the result set based on one or more columns in ascending or descending order. It helps in presenting data in a specific order.

A primary key is a special type of unique key that uniquely identifies each record in a table and is automatically created when defining a table. A unique key ensures that a column or a set of columns has unique values but does not automatically define the record's identity.

An INDEX is a database structure that improves the speed of data retrieval operations. It allows the database engine to quickly locate specific rows based on the values in the indexed columns.

DDL (Data Definition Language) is used to define and modify the structure of database objects, such as tables, indexes, and views. DML (Data Manipulation Language) is used to manage and manipulate the data within those objects, such as inserting, updating, and deleting records.

A self-join is a join operation where a table is joined with itself. It is useful when a table has a hierarchical or recursive structure, and you need to retrieve related data from the same table.

Triggers are special types of stored procedures that are automatically executed in response to specific events, such as INSERT, UPDATE, or DELETE operations on a table. They are used to enforce business rules, maintain data integrity, or perform additional actions based on the event.