Query

Key points of this
  • It’s a command to the database.
  • These are search keywords that you enter into a search engine.
I’ll write it simply.

What is a query ?

It is a command to the database like “Hey! Do this.”

or

Search keywords that you enter into a search engine when researching something

The term query refers to a command or request made to a database or search engine. Its meaning depends on the context.

1. Queries in Databases

In the context of databases, a query is a command used to retrieve or manipulate data. It instructs the database to perform specific tasks.

  • Definition: A command or request made to a database, usually written in SQL (Structured Query Language).
  • Example: To retrieve user information, you might write a SQL query like SELECT * FROM users WHERE age > 25;.

SQL vs. Query:

  • SQL: Stands for Structured Query Language, a language used to write queries.
  • Query (SQL Query): The actual command written in SQL.

While queries can be written in languages other than SQL, SQL is commonly used, so the terms “query” and “SQL query” are often used interchangeably.

2. Queries in Search Engines

In the context of search engines, a query is a keyword or phrase entered to find information.

  • Definition: Keywords or phrases entered into a search engine to specify what information you are looking for.
  • Example: When you enter “pizza recipe” into Google or Yahoo!, that search term is called a query.

Search Engine Queries:

  • The input search keywords are referred to as “queries” or “search queries.” The search engine uses these to find relevant web pages.

Summary

  • Database Query: A command to the database.
  • Search Engine Query: A search keyword or phrase.

When you see the term “query,” understand it as referring to either a database command or a search keyword, depending on the context.