SQLlekérdezés

SQLlekérdezés is the Hungarian term for an SQL query. SQL, or Structured Query Language, is a standardized programming language used for managing and manipulating data held in relational database management systems (RDBMS). A query, in this context, is a request for information from a database.

SQLlekérdezés allows users to retrieve specific data, insert new data, update existing data, and delete data from a database. Common operations include selecting data (using the SELECT statement), filtering it based on certain criteria (using the WHERE clause), joining tables to combine information from multiple sources, and aggregating data (using functions like COUNT, SUM, AVG).

The structure of a basic SQLlekérdezés is typically declarative, meaning the user specifies what data they want, rather than how to retrieve it. The RDBMS then interprets the query and executes the necessary steps to fulfill the request. Understanding SQLlekérdezés is fundamental for anyone working with relational databases, including database administrators, developers, and data analysts. Mastery of SQLlekérdezés enables efficient data retrieval and manipulation, which is crucial for many applications and business intelligence tasks.