Introduction to Operators

Operators in MySQL are essential for performing various operations in SQL queries. This guide focuses on comparison and logical operators, which allow you to compare and evaluate conditions to retrieve specific data from your database.


Comparison Operators

Comparison operators are used to compare values in SQL. Here are some commonly used operators:

  • =
    : Equal to
  • !=
    or
    <>
    : Not equal to
  • <
    : Less than
  • <=
    : Less than or equal to
  • >
    : Greater than
  • >=
    : Greater than or equal to

Example of using a comparison operator:

SELECT product_name
FROM products
WHERE price < 50;

This query retrieves product names where the price is less than 50.


Logical Operators

Logical operators are used to combine multiple conditions in SQL. Here are some commonly used logical operators:

  • AND
    : Returns true if all conditions are true
  • OR
    : Returns true if any condition is true
  • NOT
    : Negates a condition

Example of using logical operators:

SELECT product_name
FROM products
WHERE category = 'Electronics' AND price < 500;

This query retrieves product names from the "Electronics" category with a price less than 500.


Conclusion

MySQL comparison and logical operators are fundamental for filtering and retrieving specific data from your database. You've learned how to use comparison operators such as

=
,
<
, and logical operators like
AND
,
OR
in your SQL queries. As you advance in your SQL skills, mastering operators will be crucial for precise data retrieval and manipulation.