The difference between where and on in mysql

The difference between WHERE and ON in MySQL is: Usage: WHERE is used to filter records, while ON is used to join tables. Statements: WHERE is used in SELECT, UPDATE, DELETE statements, while ON is used in JOIN statements. Clause: WHERE condition is in WHERE clause and ON condition is in ON clause. Scope: WHERE can only be used for a single table, while ON can be used to join multiple tables. Purpose: WHERE is used to filter data, while ON is used to establish relationships between tables.

The difference between WHERE and ON in MySQL

In MySQL, WHERE and ON are both used for filtering Keywords for data tables, but they differ in usage and purpose:

WHERE keyword

• is used in SELECT, UPDATE, and DELETE statements
• Used to filter returned records or modified/deleted records
• Conditions are placed in the WHERE clause to specify the conditions to be met
• Can only be used for a single table, cannot be used to join multiple tables

ON keyword

• is used in the JOIN statement
• is used to specify Connection conditions when connecting multiple tables
• Conditions are placed in the ON clause to specify the basis for connecting records between two tables
• Can be used to connect multiple tables through comparison Column values ​​of different tables to establish relationships

Summary

##FeaturesWHEREONUsageFilter recordsConnect tableStatementSELECT, UPDATE, DELETEJOINClauseWHEREONRangeSingle tableMultiple tables##Purpose

Filter data	Establish table relationship

Example

Filter records:

<code class="sql">SELECT * FROM employees WHERE salary > 50000;</code>

Join table:

<code class="sql">SELECT * FROM employees AS e JOIN departments AS d ON e.department_id = d.id;</code>

I hope this information will be helpful for you to understand the difference between WHERE and ON in MySQL.

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