Master SQL BETWEEN operator: filter data within a certain range

SQL BETWEEN operator: efficiently filter data

SQL's BETWEEN operator is a powerful tool for filtering specific data ranges, and can quickly locate records between two values, which can be numbers, dates, or text (depending on the database's sorting rules).

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grammar

 <code class="sql">SELECT column1, column2, ... FROM table_name WHERE column_name BETWEEN value1 AND value2;</code>

• The BETWEEN clause contains upper and lower limit values ​​( value1 and value2 ) and contains boundary values.

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How it works

BETWEEN operator works as follows:

1. Numerical range filter : Used to extract rows whose column values ​​are within the specified range of values. For example, look for products that cost between 10 and 50.
2. Date range filtering : Easy to obtain records for specific date intervals. For example, search for orders from January 1, 2024 to January 31, 2024.
3. Text range filtering : Select lines whose text values ​​are in a specific range alphabetical order (depending on the database's sorting rules).

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Example

Numerical range filtering

Suppose there is a product list called products :

productid	productname	price
1	laptop	1200
2	mouse	25
3	keyboard	45
4	Monitor	200

Query :

 <code class="sql">SELECT productname, price FROM products WHERE price BETWEEN 30 AND 300;</code>

result :

productname	price
keyboard	45
Monitor	200

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Date range filtering

Suppose there is an order form called orders :

Orderid	Orderdate	customerid
101	2023-01-10	1
102	2023-01-15	2
103	2024-02-05	3

Query :

 <code class="sql">SELECT orderid, orderdate FROM orders WHERE orderdate BETWEEN '2023-01-01' AND '2023-01-31';</code>

result :

Orderid	Orderdate
101	2023-01-10
102	2023-01-15

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Text range filtering

Suppose there is a student table called students :

studentid	name
1	Alice
2	bob
3	charlie

Query :

 <code class="sql">SELECT name FROM students WHERE name BETWEEN 'a' AND 'c';</code>

Results : (The results depend on the database's sorting rules, assuming it is sorted alphabetically here)

name

Alice

bob

charlie

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Key points

1. Include boundary values : value1 and value2 are both included in the filter range.
2. Value order : Make sure that smaller values ​​are in front and larger values ​​are in back.
3. Exclude ranges : Use NOT BETWEEN to exclude specified ranges.
4. Performance optimization : For large datasets, create indexes for query columns to improve performance.

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Summarize

The BETWEEN operator is a concise method for efficiently filtering data ranges in SQL, and is widely used in various database operations. Its ease of use and efficiency make it a common tool in database management.

Author: Abhay Singh Kathayat (full stack development engineer, contact email: kaashshorts28@gmail.com)

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