SQL Query Execution Order: Logical Steps Explained
SQL query execution follows a specific logical order: FROM, JOIN, WHERE, GROUP BY, HAVING, SELECT, DISTINCT, ORDER BY & LIMIT/OFFSET.
youtube.com
The logical processing order of a SQL query can be understood by diving deeper into each step. Though SQL queries are written in a particular order, the database engine executes them differently. Below is a detailed breakdown of the logical order with a sample query for clarity:
Logical Order of SQL Execution:
1. FROM: Identify and Load the Data
2. JOIN: Combine Tables (if applicable)
3. WHERE: Filter Rows Based on Conditions
4. GROUP BY: Group Rows for Aggregation
5. HAVING: Filter Groups Based on Aggregate Conditions
6. SELECT: Select Columns or Expressions
7. DISTINCT: Rem...