SQL BETWEEN operator

In the area of database management and relational databases, SQL provides us with the power to navigate through data with precision and finesse. The BETWEEN operator is one of the cornerstones of the querying capabilities of SQL and this operator serves as a bridge for effortless sifting through the data within the given ranges and makes data retrieval and analysis a seamless process. In this blog, we provide a comprehensive guide to SQL BETWEEN operator as we dive into the depths of the Between operator and unravel the syntax, use cases, applications, and practical examples which will empower our readers with the skills to wield it in an effective manner.

Table of Contents

Introduction

The SQL BETWEEN operator is used for retrieving rows from a database table within the specified range of values and is used in conjunction with the WHERE clause. It is used for filtering data based on a specified range. The BETWEEN operator is inclusive which means that it includes both the lower and upper bounds of the specified range.

The basic syntax of the ‘BETWEEN’ Operator is as follows:

SELECT column_name(s)
FROM table_name
WHERE column_name BETWEEN value1 AND value2;

In the following syntax,

‘column_name(s)’ specifies the column(s) that we want the data to be retrieved from.
‘table_name’ is the name of the table we are querying.
‘column_name BETWEEN value1 AND value2’ specifies the actual BETWEEN condition and is used for checking whether the values in the specified column lie within the given range defined through ‘value1’ and ‘value2’.

Let us look at an example of BETWEEN operator to understand the working of this operator

Suppose that the database has a table named ‘employees’ having columns ‘employee_id’, ‘first_name’, ‘last_name’, and ‘salary’. We have to retrieve all employees whose salaries lie between $30,000 and $50,000. The query will be:

SELECT employee_id, first_name, last_name, salary
FROM employees
WHERE salary BETWEEN 30000 AND 50000;

This query returns all rows where the salary lies between $30,000 and $50,000, and since BETWEEN operator is inclusive, it also includes the data of $30,000 and $50,000.

We can also use the ‘NOT BETWEEN’ operator for retrieving rows that lie outside a specified range. The syntax for the same is:

SELECT column_name(s)
FROM table_name
WHERE column_name NOT BETWEEN value1 AND value2;

For retrieving the details of employees whose salaries do not lie between $30,000 and $50,000, the following query is used:

SELECT employee_id, first_name, last_name, salary
FROM employees
WHERE salary NOT BETWEEN 30000 AND 50000;

Applications of the BETWEEN operator

The BETWEEN operator can be used in a spectrum of applications and scenarios where we need to filter data within a specified range. Some of the common use cases where the BETWEEN operator can be used are described as follows:

Numeric Filtering of data: One of the primary applications of the BETWEEN operator is filtering the numeric data which includes filtering values such as prices, quantities, ages, and other numerical attributes in data. An example query for the same is:

SELECT product_name, price
FROM products
WHERE price BETWEEN 10 AND 50;

Filtering of dates and times: While dealing with data containing date and time, the BETWEEN operator is very useful for filtering events that occur within a specified timeframe and this can be helpful for analysis of trends, sales periods, or time-based data. An example query for the same is:

SELECT order_id, order_date
FROM orders
WHERE order_date BETWEEN '2023-01-01' AND '2023-03-31';

Textual ranges:

Even though the BETWEEN operator is usually associated with numeric and date values, the BETWEEN operator can also be used for filtering textual data. For example, the BETWEEN operator can be used for retrieving products whose names are arranged alphabetically within a certain range:

SELECT product_name
FROM products
WHERE product_name BETWEEN 'A' AND 'G';

Combining multiple filters: The BETWEEN operator can be combined with other conditions to create more complex queries and is useful to us when we have to filter data based on multiple criteria simultaneously. An example query for the same is:

SELECT employee_name, salary
FROM employees
WHERE job_title = 'Manager' AND salary BETWEEN 50000 AND 80000;

Filtering the ID ranges: In cases when we have records with numerical identities, we can use the NETWEEN operator for filtering specific ranges of IDs. This is very useful when we have to retrieve a subset of records on the basis of their IDs.

SELECT customer_name
FROM customers
WHERE customer_id BETWEEN 1001 AND 1050;

Filtering NULL values: The BETWEEN operator can be used for filtering rows having NULL values which is a very helpful feature in SQL. An example query showing how the products can be retrieved with prices within a certain range, including them with the NULL prices is:

SELECT product_name
FROM products
WHERE price BETWEEN 20 AND 100 OR price IS NULL;

Filtering using different data types: the BETWEEN operator can be used with multiple data types and not just with numbers and dates. It can be used with strings, timestamps, or other compatible data types for filtering the data within the specified range.

The versatility of the BETWEEN operator makes it a powerful operator and tool for filtering data on the basis of ranges across different scenarios and provides precise and efficient results.

For mastering the SQL BETWEEN operator, we must mind the data types that are used, ensuring that the data type of column and values in the BETWEEN condition aligns harmoniously, as mismatched data types lead to puzzling outcomes. The BETWEEN operator is inclusive, which means that it includes the specified lower and upper bounds. We must pay attention to this inclusivity while crafting our queries. While working with the date and time data, we must remember to consider time components, and depending on the situation, one might need to adjust the queries for accommodating time portions accurately.

Conclusion

This blog discussed the SQL BETWEEN operator in a detailed manner by proving an appropriate introduction, syntax, and applications. The SQL BETWEEN operator is a versatile tool for filtering and querying data within specified ranges and has a lot of applications. Mastering the BETWEEN operator helps us empower to harness the full potential of SQL in the management and analysis of data.

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