How does SQL query work?

Question

SQL Query mainly works in three phases . 1) Row filtering - Phase 1: Row filtering - phase 1 are done by FROM, WHERE , GROUP BY , HAVING clause. 2) Column filtering: Columns are filtered by SELECT clause. 3) Row filtering - Phase 2: Row filtering - phase 2 are done by DISTINCT , ORDER BY , LIMIT clause.

What is SQL and how it works?

SQL is the most common language for extracting and organising data that is stored in a relational database. A database is a table that consists of rows and columns. SQL is the language of databases. It facilitates retrieving specific information from databases that are further used for analysis.

How are the SQL queries executed?

SQL's from clause selects and joins your tables and is the first executed part of a query. This means that in queries with joins, the join is the first thing to happen. It's a good practice to limit or pre-aggregate tables before potentially large joins, which can otherwise be very memory intensive.

What is SQL query with example?

An SQL SELECT statement retrieves records from a database table according to clauses (for example, FROM and WHERE ) that specify criteria. The syntax is: SELECT column1, column2 FROM table1, table2 WHERE column2='value';

How does a query work in a database?

A query in a database is a request for information stored within a database management system (DBMS), which is the software program that maintains data. Users can make a query to retrieve data or change information in a database, such as adding or removing data.

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