preface

@TOC This article discusses the various operators used in SQL in the following order:

This article discusses the various operators used in SQL in the following order:

  • What is an operator?
  • Classification of operators:

Arithmetic operator Comparison operator Logic operator

What is an operator?

SQL operators are reserved keys used to perform arithmetic, logical, and comparison operations in the WHERE clause of AN SQL statement. Operators act as concatenators in SQL statements to satisfy multiple conditions in the statement.

Classification of operators:

Arithmetic operator

These operators are used to perform addition, multiplication, subtraction, etc.

Example:

SELECT 40 + 20;
 
SELECT 40 - 20;
 
SELECT 40 * 20;
 
SELECT 40 / 20;
 
SELECT 40 % 20;
Copy the code

Output:

60, 20, 800, 2, 0Copy the code

Comparison operator

These operators are used to perform equal, greater than, less than, and so on.

Example:

To better understand, I’ll consider the following table to perform various operations.

Example (equal to) :

SELECT * FROM Students
WHERE Age = 20;
Copy the code

Output:

Examples (greater than) :

SELECT * FROM students
WHERE Age > 23;
Copy the code

Output:

Example (less than or equal to) :

SELECT * FROM students
WHERE Age <= 21;
Copy the code

Output:

Example (not equal to) :

SELECT * FROM students
WHERE Age <> 25;
Copy the code

Output:

Logical operator

Example:

I will consider the student table mentioned above to perform some operations.

Example (ANY)

SELECT * FROM Students
WHERE Age > ANY (SELECT Age FROM Students WHERE Age > 21);
Copy the code

Output:Examples (BETWEEN & AND)

SELECT * FROM Students
WHERE Age BETWEEN 22 AND 25;
Copy the code

Output:

Example (IN)

SELECT * FROM Students
WHERE Age IN('23', '20');
Copy the code

Output:

In this article, I just cited the most common but example, of course, database and network technology is not quite the same, the network has a lot of original things, but the database is biased to actual combat, need constant practice to learn better, learn faster!