SQL BETWEEN — সম্পূর্ণ ২ ঘন্টার লাইভ ক্লাস নোট

01

কেন BETWEEN — আগে গল্প

১৫ মিনিট

মূল প্রশ্ন: কোনো value একটি নির্দিষ্ট range-এর মধ্যে আছে কিনা কীভাবে খুঁজব?

জিজ্ঞেস করো

যেসব student-এর marks 70 থেকে 80-এর মধ্যে, তাদের কীভাবে খুঁজব?

যেসব employee-এর salary 50,000 থেকে 80,000-এর মধ্যে?

January থেকে March-এর মধ্যে হওয়া orders?

গল্প ১ — School (৫,০০০ student)

Teacher: “marks 70 থেকে 80-এর মধ্যে list দাও।”

45 52 67 70 72 75 78 80 83 91

ক্লাসকে জিজ্ঞেস

70, 71, 72… 80 manually লিখে search করা কি practical?

কঠিন কিন্তু কাজ করে

WHERE marks >= 70 AND marks <= 80;

একই কাজ সহজভাবে: BETWEEN।

গল্প ২ — Employee Salary

50,000 ─────────────── 80,000 Salary Range → BETWEEN

গল্প ৩ — E-commerce Price

500 ↓ [ Products we want ] ↓ 2000

গল্প ৪ — Bank Balance

balance 10,000 থেকে 100,000 — range-based filtering।

গল্প ৫ — Date Range

2026-এর January 1 থেকে January 31-এর orders — BETWEEN শুধু number নয়, date-এও।

অনেকগুলো individual value ↓ একটি range ↓ BETWEEN ↓ Matching records

WHERE ↓ Range Condition ↓ BETWEEN ↓ Lower Value … Upper Value ↓ Matching Records

মনে রাখো: BETWEEN = “এই value থেকে ওই value-এর মধ্যে”

02

BETWEEN কী?

১০ মিনিট

BETWEEN = SQL operator যা বলে: column-এর value কি দুই সীমার মধ্যে?

কেন: range লেখা ছোট ও পড়া সহজ
কখন: marks, salary, price, date — continuous range
Range: শুরু থেকে শেষ পর্যন্ত ব্যবধান
Lower bound: ছোট/শুরুর সীমা
Upper bound: বড়/শেষ সীমা

শুধু number নয় — date (এবং অনেক সময় text order) ও ব্যবহার হয়।

Teacher Tip: “৫ থেকে ১০ নম্বরের student খুঁজে বের করো।” → Lower = 5, Upper = 10।

Lower Bound = 5 Upper Bound = 10

03

Basic BETWEEN সিনট্যাক্স

১০ মিনিট

SELECT * FROM students WHERE marks BETWEEN 70 AND 80;

SELECT → কী দেখতে চাই? FROM → কোন table? WHERE → কোন condition? marks → কোন column? BETWEEN → Range-এর মধ্যে 70 → শুরু / Lower 80 → শেষ / Upper

সবচেয়ে গুরুত্বপূর্ণ নিয়ম: BETWEEN সাধারণত দুই boundary-ই include করে।

70 ✅ 71 ✅ … 79 ✅ 80 ✅ 70 ================================= 80 ↑ ↑ Included Included

Common confusion: অনেকে ভেবে 71–79 শুধু — ভুল। 70 ও 80ও আসে।

04

BETWEEN vs >= AND <=

১৫ মিনিট

BETWEEN

WHERE marks BETWEEN 70 AND 80;

>= AND <=

WHERE marks >= 70 AND marks <= 80;

সাধারণ numeric comparison-এ দুটোই একই range logic।

BETWEEN	AND (>= <=)
`marks BETWEEN 70 AND 80`	`marks >= 70 AND marks <= 80`
Shorter	Longer
Easy to read	More explicit
Good for simple ranges	Useful for complex / datetime control

Teacher Tip: BETWEEN মূলত range লেখাকে সহজ করে — magic নয়।

05

Numeric BETWEEN

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Sample students (১৮ rows):

id	name	dept	marks	age
1	Rahim	CSE	72	19
2	Karim	EEE	65	21
3	Sara	CSE	80	18
4	Nila	BBA	70	20
5	Jamal	CSE	55	22
6	Ayesha	EEE	78	19
7	Hasan	BBA	91	23
8	Mitu	CSE	74	18
9	Rafi	EEE	68	20
10	Lina	BBA	83	21
11	Omar	CSE	76	19
12	Tania	EEE	60	24
13	Imran	BBA	79	22
14	Farah	CSE	45	17
15	Sabbir	EEE	88	20
16	Rina	BBA	71	18
17	Kabir	CSE	67	25
18	Meena	EEE	75	19

Example 1 — Marks 70–80

SELECT * FROM students WHERE marks BETWEEN 70 AND 80;

70 ===== INCLUDE ===== 80

Rahim 72, Sara 80, Nila 70, Ayesha 78, Mitu 74, Omar 76, Imran 79, Rina 71, Meena 75 (65/68/67/55/45/83/91 বাদ)

লাইন বাই লাইন: WHERE marks filter → BETWEEN inclusive → matching rows।

Beginner mistake: 80 বাদ ভেবে নেওয়া।

Example 2 — Age 18–22

SELECT * FROM students WHERE age BETWEEN 18 AND 22;

age 17 ও 23–25 বাদ; 18…22 include

Example 3 — Salary

SELECT * FROM employees WHERE salary BETWEEN 50000 AND 80000;

Example 4 — Product price

SELECT * FROM products WHERE price BETWEEN 500 AND 2000;

Remember: number-এ সাধারণত quotes লাগে না: BETWEEN 500 AND 2000

06

NOT BETWEEN

১০ মিনিট

SELECT * FROM products WHERE price NOT BETWEEN 500 AND 2000;

BETWEEN → Range-এর ভিতরে NOT BETWEEN → Range-এর বাইরে 0 ---- 499 | 500 ========= 2000 | 2001 ---- ∞ INCLUDE (BETWEEN) বাইরের অংশই NOT BETWEEN

499 ও 2001 আসে; 500–2000 আসে না।

07

BETWEEN with Dates / DATETIME

২০ মিনিট

January 1 ↓ January 31

Business: “January মাসের সব orders বের করো।”

SELECT * FROM orders WHERE order_date BETWEEN '2026-01-01' AND '2026-01-31';

Monthly / Quarterly / Joining year

-- Q1 2026 WHERE order_date BETWEEN '2026-01-01' AND '2026-03-31'; -- Joined in 2025 WHERE joining_date BETWEEN '2025-01-01' AND '2025-12-31';

DATETIME সতর্কতা (বিগিনার → প্রো অভ্যাস)

যদি column-এ time থাকে, যেমন 2026-01-31 18:30:00, তাহলে end boundary '2026-01-31' অনেক engine-এ midnight (00:00:00) বোঝায় — সন্ধ্যার row বাদ যেতে পারে।

Safer half-open range (professional)

WHERE order_date >= '2026-01-01' AND order_date < '2026-02-01';

পুরো January (time সহ) ধরতে: start inclusive, next month exclusive।

08

BETWEEN + AND / OR

১৫ মিনিট

BETWEEN + AND

SELECT * FROM employees WHERE salary BETWEEN 50000 AND 80000 AND department = 'IT';

Salary Range + IT Department → Final Result

BETWEEN + OR (দুই range)

SELECT * FROM products WHERE price BETWEEN 500 AND 1000 OR price BETWEEN 5000 AND 10000;

500 ───── 1000 5000 ───── 10000

OR দিয়ে দুই আলাদা ব্যান্ড যোগ করা যায়।

09

BETWEEN + ORDER BY + LIMIT

১০ মিনিট

Business: “500 থেকে 5,000 টাকার মধ্যে সবচেয়ে দামি 10টি product দেখাও।”

SELECT * FROM products WHERE price BETWEEN 500 AND 5000 ORDER BY price DESC LIMIT 10;

Products ↓ Price Range Filter (500–5000) ↓ Sort Highest → Lowest ↓ Take Top 10

10

BETWEEN + GROUP BY

১০ মিনিট

“50,000–80,000 salary range-এর employees department অনুযায়ী count করো।”

SELECT department, COUNT(*) AS employee_count FROM employees WHERE salary BETWEEN 50000 AND 80000 GROUP BY department;

FROM → WHERE + BETWEEN → GROUP BY → COUNT → Result

আগে শেখা GROUP BY-এর সাথে range filter মিলিয়ে দাও।

11

= / IN / BETWEEN / LIKE / REGEXP

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Operator	Main Purpose	Example
`=`	Exact value	`age = 20`
`IN`	Specific values	`age IN (18,20,22)`
`BETWEEN`	Range	`age BETWEEN 18 AND 22`
`LIKE`	Simple text pattern	`name LIKE 'A%'`
`REGEXP`	Complex text pattern	`name REGEXP '^A'`

Specific values → IN

WHERE age IN (18, 20, 22)

শুধু ১৮, ২০, ২২ — ১৯/২১ নেই।

Continuous range → BETWEEN

WHERE age BETWEEN 18 AND 22

১৮ থেকে ২২ সব বয়স।

12

BETWEEN vs WHERE >= <=

১০ মিনিট

Requirement	BETWEEN	>= <=
Simple range	Excellent	Good
Readability	High	High
Complex conditions	Limited	More flexible
DateTime handling	Requires care	Often clearer

BETWEEN inclusive; explicit inequalities দিয়ে datetime boundary নিয়ন্ত্রণ সহজ।

13

E-commerce Business Case Study

২০ মিনিট

Products (নমুনা)

id	name	category	brand	price	stock
P01	USB Cable	Accessories	Anker	450	120
P02	Mouse	Accessories	Logitech	850	80
P03	Keyboard	Accessories	Logitech	1800	45
P04	SSD 500GB	Storage	Samsung	4200	30
P05	HDD 1TB	Storage	WD	3500	25
P06	Monitor 24	Display	Dell	14500	12
P07	Webcam	Accessories	Logitech	2200	40
P08	Headset	Audio	Sony	3200	35
P09	Power Bank	Accessories	Xiaomi	1500	60
P10	Router	Network	TP-Link	2800	22
P11	Phone Case	Accessories	Spigen	600	200
P12	Laptop Stand	Accessories	Generic	1200	50

Orders (নমুনা)

order_id	customer_id	order_date	total_amount	city
O01	C1	2026-01-05	12000	Dhaka
O02	C2	2026-01-18	45000	Chittagong
O03	C3	2026-02-02	8000	Dhaka
O04	C4	2026-03-10	32000	Sylhet
O05	C5	2026-01-31	55000	Dhaka
O06	C6	2026-04-01	15000	Khulna
O07	C7	2026-02-20	21000	Rajshahi
O08	C8	2026-03-28	9500	Dhaka

Employees (নমুনা)

id	name	dept	salary	joining_date
E01	Arif	IT	55000	2025-03-01
E02	Bela	Sales	42000	2024-06-15
E03	Chayan	IT	78000	2025-11-20
E04	Dipa	HR	60000	2025-01-10
E05	Emon	Sales	90000	2023-08-01
E06	Faria	IT	50000	2025-07-07
E07	Gazi	Finance	70000	2024-12-01
E08	Hena	HR	48000	2025-09-15

সমাধান (১১টি প্রশ্ন)

WHERE price BETWEEN 500 AND 2000 → Mouse, Keyboard, Power Bank, Phone Case, Laptop Stand…
WHERE price BETWEEN 2000 AND 5000 → SSD, HDD, Webcam, Headset, Router…
WHERE price NOT BETWEEN 500 AND 2000
WHERE price BETWEEN 500 AND 5000 ORDER BY price DESC LIMIT 10
WHERE total_amount BETWEEN 10000 AND 50000
WHERE order_date BETWEEN '2026-01-01' AND '2026-01-31' (DATE) / half-open যদি DATETIME
Q1: BETWEEN '2026-01-01' AND '2026-03-31'
Date range + ORDER BY total_amount DESC
salary BETWEEN 50000 AND 80000
joining_date BETWEEN '2025-01-01' AND '2025-12-31'
WHERE salary BETWEEN 50000 AND 80000 GROUP BY department + COUNT

14

MySQL Workbench Practical

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Step 1–3: DB + table + data

CREATE DATABASE between_lab; USE between_lab; CREATE TABLE products ( product_id INT PRIMARY KEY, product_name VARCHAR(80), category VARCHAR(40), brand VARCHAR(40), price DECIMAL(10,2), stock INT ); INSERT INTO products VALUES (1,'USB Cable','Accessories','Anker',450,120), (2,'Mouse','Accessories','Logitech',850,80), (3,'Keyboard','Accessories','Logitech',1800,45), (4,'SSD 500GB','Storage','Samsung',4200,30), (5,'HDD 1TB','Storage','WD',3500,25), (6,'Monitor 24','Display','Dell',14500,12), (7,'Webcam','Accessories','Logitech',2200,40), (8,'Headset','Audio','Sony',3200,35), (9,'Power Bank','Accessories','Xiaomi',1500,60), (10,'Router','Network','TP-Link',2800,22), (11,'Phone Case','Accessories','Spigen',600,200), (12,'Laptop Stand','Accessories','Generic',1200,50);

Step 4–12 practice checklist

SELECT * FROM products;
Numeric BETWEEN 500–2000
NOT BETWEEN
Date BETWEEN (orders table তৈরি করে)
BETWEEN + AND (category)
BETWEEN + OR (দুই price band)
ORDER BY price DESC
LIMIT 5
GROUP BY category with price range

SELECT * FROM products WHERE price BETWEEN 500 AND 2000 ORDER BY price DESC LIMIT 5;

Expected: Keyboard 1800, Power Bank 1500, Laptop Stand 1200, Mouse 850, Phone Case 600

Mistake: BETWEEN 2000 AND 500 (reverse) — empty/unexpected। Lower আগে লেখো।

Best practice: DATE vs DATETIME আলাদা করে ভাবো; month filter-এ half-open বিবেচনা করো।

15

Common Beginner Mistakes

১০ মিনিট

1 — Boundary confusion

BETWEEN 70 AND 80 মানে সাধারণত 70–80 inclusive — শুধু 71–79 নয়।

2 — Reversing values

-- Wrong habit WHERE price BETWEEN 2000 AND 500;

Lower → Upper ক্রম রাখো।

3 — Unrelated values

BETWEEN সবচেয়ে ভালো ordered/continuous range-এ। ছিটানো নির্দিষ্ট মান → IN।

4 — BETWEEN vs IN

age IN (18, 20, 22) -- only three ages age BETWEEN 18 AND 22 -- 18,19,20,21,22

5 — DATETIME

WHERE order_date >= '2026-01-01' AND order_date < '2026-02-01';

6 — Quotes

Numbers: BETWEEN 500 AND 2000 · Dates: BETWEEN '2026-01-01' AND '2026-01-31'

16

SQL Execution Flow (simplified)

৫ মিনিট

FROM ↓ WHERE ← BETWEEN এখানে কাজ করে ↓ GROUP BY ↓ HAVING ↓ SELECT ↓ DISTINCT ↓ ORDER BY ↓ LIMIT

এটি simplified teaching model — optimizer ভেতর থেকে আলাদা হতে পারে।

WHERE → Range Condition → BETWEEN → Rows inside range survive

17

Industry Use Cases

৮ মিনিট

Data Analyst: salary / sales / spending / age groups
Data Scientist: feature filter, explore ranges
BI: KPI date filters, sales periods
Finance: transaction amounts, revenue bands
HR: salary bands, joining years
E-commerce: price filters, order value, promo windows

18

Performance Tips (beginner)

৫ মিনিট

Range filter সাধারণ; সঠিক index থাকলে দ্রুত হতে পারে
বারবার BETWEEN করা column (price, order_date) index candidate
Indexed column-এর চারপাশে অপ্রয়োজনীয় function এড়াও
DATETIME-এ সঠিক boundary ব্যবহার করো
শুধু দরকারি range নাও — হাজার হাজার অপ্রয়োজনীয় row টানো না

19

Interactive Classroom Activities

১৫ মিনিট

কার্ডে ক্লিক করে উত্তর দেখো।

Activity 1 — Predict: marks BETWEEN 70 AND 80 (45,52,67,70,72,75,78,80,83,91)

70,72,75,78,80 (67/83 বাদ)

Activity 2 — Is 70 included?

হ্যাঁ — inclusive lower bound

Activity 3 — Is 80 included?

হ্যাঁ — inclusive upper bound

Activity 4 — 18, 20 and 22 only: BETWEEN or IN?

IN (18,20,22) — specific values

Activity 5 — Price 500 to 1000: BETWEEN or LIKE?

BETWEEN — numeric range, LIKE text pattern

Activity 6 — Mistake? WHERE price BETWEEN 2000 AND 500

Bounds reversed — use BETWEEN 500 AND 2000

Activity 7 — Convert: salary >= 50000 AND salary <= 80000

salary BETWEEN 50000 AND 80000

Activity 8 — Convert back: age BETWEEN 18 AND 22

age >= 18 AND age <= 22

Activity 9 — January 2026 DATE filter

order_date BETWEEN '2026-01-01' AND '2026-01-31' (DATE)

Activity 10 — Products 500–5000 top 5 by price

WHERE price BETWEEN 500 AND 5000 ORDER BY price DESC LIMIT 5

Activity 11 — NOT BETWEEN 500 AND 2000: 450?

হ্যাঁ — range-এর বাইরে

Activity 12 — NL: IT + salary 50k–80k

WHERE salary BETWEEN 50000 AND 80000 AND department = 'IT'

20

Mini Project — E-commerce Sales Analysis

১৫ মিনিট

Part 13-এর tables ব্যবহার করে company analytics:

Products 500–2000
Products outside 500–2000
Orders 10000–50000
January 2026 orders
Q1 2026 orders
Employees 50000–80000
Hired during 2025
Top 10 products 500–5000
Dept-wise count in salary range
Dept-wise AVG(salary) in same range

SELECT department, AVG(salary) AS avg_salary FROM employees WHERE salary BETWEEN 50000 AND 80000 GROUP BY department;

21

BETWEEN Cheat Sheet

৫ মিনিট

BETWEEN

number:
price BETWEEN 500 AND 2000

date:
order_date BETWEEN '2026-01-01' AND '2026-01-31'

NOT BETWEEN:
price NOT BETWEEN 500 AND 2000

multiple:
salary BETWEEN 50000 AND 80000
AND department = 'IT'

DATETIME month (safer):
order_date >= '2026-01-01'
AND order_date < '2026-02-01'

BETWEEN = inclusive range
10 ✅ … 20 ✅

শেষে মনে রাখো: Need filtering → WHERE → Need a range → BETWEEN → salary BETWEEN 50000 AND 80000

22

MCQ (২০+)

১৫ মিনিট

MCQ 1. BETWEEN মানে? A) exact B) range C) pattern D) sort

B — নির্দিষ্ট range

MCQ 2. BETWEEN 70 AND 80-এ 70? A) না B) হ্যাঁ C) শুধু MySQL D) error

B — সাধারণত include

MCQ 3. 80 include? A) না B) হ্যাঁ C) কখনো না D) শুধু DATE

B

MCQ 4. Equivalent? A) >70 AND <80 B) >=70 AND <=80 C) =70 OR =80 D) IN(70,80)

B

MCQ 5. NOT BETWEEN করে? A) ভিতরে B) বাইরে C) sort D) group

B

MCQ 6. Date-এ quotes? A) না B) হ্যাঁ সাধারণত C) শুধু number D) কখনো না

B

MCQ 7. Number-এ quotes? A) সাধারণত না B) অবশ্যই C) শুধু BETWEEN D) error

A

MCQ 8. age IN(18,20,22) vs BETWEEN 18 AND 22

IN = নির্দিষ্ট; BETWEEN = সব বয়স ১৮–২২

MCQ 9. BETWEEN + AND মানে? A) দুই range B) range + অন্য condition C) OR D) LIMIT

B

MCQ 10. দুই price band? A) AND B) OR দুই BETWEEN C) LIKE D) REGEXP

B

MCQ 11. Top 10 in range? A) HAVING B) ORDER BY + LIMIT C) DISTINCT D) JOIN

B

MCQ 12. Dept count in salary band? A) GROUP BY B) LIKE C) REGEXP D) UNION

A

MCQ 13. DATETIME Jan end risk? A) কোনো সমস্যা নেই B) midnight end miss করতে পারে C) সবসময় error D) শুধু Oracle

B

MCQ 14. Safer month pattern?

>= '2026-01-01' AND < '2026-02-01'

MCQ 15. BETWEEN vs LIKE

BETWEEN range; LIKE text pattern

MCQ 16. BETWEEN vs REGEXP

BETWEEN range; REGEXP complex text

MCQ 17. Lower/Upper reverse?

Unexpected/empty — সঠিক ক্রম লেখো

MCQ 18. Inclusive মানে?

দুই boundary সহ

MCQ 19. salary BETWEEN 50000 AND 80000-এ 50000?

হ্যাঁ

MCQ 20. Q1 2026 DATE?

BETWEEN '2026-01-01' AND '2026-03-31'

MCQ 21. Best for continuous ages 18–22?

BETWEEN

MCQ 22. Best for only 18,20,22?

IN

23

Viva Questions

১০ মিনিট

Viva 1. BETWEEN কী?

Range-এর মধ্যে value খোঁজার operator

Viva 2. কেন ব্যবহার?

Range লেখা সহজ ও পড়া যায়

Viva 3. Boundary include?

সাধারণত হ্যাঁ — দুই দিক

Viva 4. Number-এ ব্যবহার?

হ্যাঁ

Viva 5. Date-এ ব্যবহার?

হ্যাঁ

Viva 6. NOT BETWEEN?

Range-এর বাইরে

Viva 7. BETWEEN vs IN?

Range vs নির্দিষ্ট list

Viva 8. BETWEEN vs >= <=?

একই numeric logic; BETWEEN ছোট

Viva 9. AND সাথে?

হ্যাঁ — অতিরিক্ত filter

Viva 10. OR সাথে?

হ্যাঁ — একাধিক range

Viva 11. GROUP BY সাথে?

হ্যাঁ — আগে WHERE filter

Viva 12. ORDER BY সাথে?

হ্যাঁ — filter পর sort

Viva 13. DATETIME issue?

End date midnight — time miss হতে পারে

Viva 14. Safer datetime?

>= start AND < next day/month

Viva 15. Quotes numbers?

সাধারণত লাগে না

Viva 16. Quotes dates?

লাগে

Viva 17. Reverse bounds?

এড়াও — lower first

Viva 18. LIKE কখন?

Text pattern — price range নয়

Viva 19. Teaching flow-এ BETWEEN কোথায়?

WHERE-এর ভিতরে

Viva 20. Core memory?

BETWEEN = inclusive range filter

Viva 21. Half-open মানে?

Start include, end exclusive

Viva 22. Industry use?

Salary band, sales period, price filter

24

Interview Top 30

১৫ মিনিট

IV 1. Employees salary 50k–80k

WHERE salary BETWEEN 50000 AND 80000 · ভুল: exclusive ভাবা · ফলো: IT only? · ইউজ: HR

IV 2. Products two prices

price BETWEEN a AND b · ভুল: reverse · ফলো: NOT BETWEEN? · ইউজ: catalog

IV 3. Orders two dates

order_date BETWEEN d1 AND d2 · ভুল: quotes ভুলে · ফলো: DATETIME? · ইউজ: sales

IV 4. Inclusive?

সাধারণত হ্যাঁ · ভুল: 71–79 · ফলো: docs? · ইউজ: reporting

IV 5. BETWEEN vs IN

range vs list · ভুল: একই ভাবা · ফলো: ages example · ইউজ: filters

IV 6. BETWEEN vs >= <=

readable vs flexible · ভুল: সবসময় এক · ফলো: datetime · ইউজ: code review

IV 7. NOT BETWEEN

outside range · ভুল: != · ফলো: price bands · ইউজ: outliers

IV 8. DATETIME BETWEEN

midnight end risk · ভুল: ignore time · ফলো: half-open · ইউজ: logs

IV 9. Entire month

>= m1 AND < next month · ভুল: only day 1–31 DATE ধরে DATETIME · ফলো: timezone? · ইউজ: BI

IV 10. GROUP BY + BETWEEN

WHERE band then GROUP · ভুল: HAVING-এ BETWEEN অপ্রয়োজনীয় · ফলো: COUNT · ইউজ: HR dashboards

IV 11. ORDER BY + LIMIT

filter→sort→limit · ভুল: LIMIT first · ফলো: top N · ইউজ: UI

IV 12. Two ranges OR

BETWEEN … OR BETWEEN … · ভুল: AND · ফলো: three bands · ইউজ: promos

IV 13. Quotes mistake

dates quoted, numbers usually not · ভুল: '500' always · ফলো: cast? · ইউজ: debugging

IV 14. Reverse BETWEEN

unexpected · ভুল: hope auto-swap · ফলো: engine? · ইউজ: QA

IV 15. Index tip

range columns index candidate · ভুল: function on column · ফলো: EXPLAIN · ইউজ: DBA

IV 16. Q1 filter

Jan1–Mar31 or half-open to Apr1 · ভুল: month=1 OR 2 only · ফলো: fiscal Q · ইউজ: finance

IV 17. Joining year 2025

joining BETWEEN '2025-01-01' AND '2025-12-31' · ভুল: YEAR() always · ফলো: index · ইউজ: HR

IV 18. Price NOT BETWEEN

outside · ভুল: NULL surprise · ফলো: NULL handling later · ইউজ: cleansing

IV 19. Combine dept

BETWEEN AND dept= · ভুল: OR · ফলো: multiple depts IN · ইউজ: payroll

IV 20. Teaching model flow

WHERE hosts BETWEEN · ভুল: after LIMIT · ফলো: HAVING vs WHERE · ইউজ: interviews

IV 21. Age groups

BETWEEN for bands · ভুল: LIKE · ফলো: CASE bands · ইউজ: analytics

IV 22. Sales amount band

total_amount BETWEEN · ভুল: REGEXP · ফলো: currency · ইউজ: BI

IV 23. Top products in band

BETWEEN + ORDER + LIMIT · ভুল: GROUP without need · ফলো: pagination · ইউজ: merchandising

IV 24. Equivalent rewrite

show >= AND <= · ভুল: > AND < · ফলো: prove with data · ইউজ: mentoring

IV 25. When avoid BETWEEN

non-contiguous lists · ভুল: force BETWEEN · ফলো: IN · ইউজ: code quality

IV 26. Bank balance range

balance BETWEEN · ভুল: string compare · ফলো: DECIMAL · ইউজ: banking

IV 27. Performance beginner

index + selective range · ভুল: SELECT * always · ফলো: covering index · ইউজ: large tables

IV 28. Half-open explain

start include end exclude · ভুল: both exclusive · ফলো: day ranges · ইউজ: event logs

IV 29. Common bug quotes on numbers

prefer unquoted numbers · ভুল: always string · ফলো: collation · ইউজ: debugging

IV 30. Final rule

BETWEEN = inclusive range tool · ভুল: regex substitute · ফলো: choose operator · ইউজ: daily SQL

25

Homework

বাড়ি

প্রশ্ন (আগে নিজে সমাধান করো):

Products priced 500–2000
Products priced 2000–5000
Products outside 500–2000
Orders amount 10000–50000
Orders January 2026
Orders Q1 2026
Employees salary 50000–80000
Employees hired in 2025
Top 5 products price 500–5000
Dept-wise count for salary 50000–80000

উত্তর (ক্লিক করে দেখো):

উত্তর ১

SELECT * FROM products WHERE price BETWEEN 500 AND 2000;

উত্তর ২

SELECT * FROM products WHERE price BETWEEN 2000 AND 5000;

উত্তর ৩

SELECT * FROM products WHERE price NOT BETWEEN 500 AND 2000;

উত্তর ৪

SELECT * FROM orders WHERE total_amount BETWEEN 10000 AND 50000;

উত্তর ৫

WHERE order_date BETWEEN '2026-01-01' AND '2026-01-31'; (DATE) / half-open যদি DATETIME

উত্তর ৬

WHERE order_date BETWEEN '2026-01-01' AND '2026-03-31';

উত্তর ৭

WHERE salary BETWEEN 50000 AND 80000;

উত্তর ৮

WHERE joining_date BETWEEN '2025-01-01' AND '2025-12-31';

উত্তর ৯

WHERE price BETWEEN 500 AND 5000 ORDER BY price DESC LIMIT 5;

উত্তর ১০

SELECT department, COUNT(*) FROM employees WHERE salary BETWEEN 50000 AND 80000 GROUP BY department;

বিষয়সূচী

কেন BETWEEN — আগে গল্প

গল্প ১ — School (৫,০০০ student)

গল্প ২ — Employee Salary

গল্প ৩ — E-commerce Price

গল্প ৪ — Bank Balance

গল্প ৫ — Date Range

BETWEEN কী?

Basic BETWEEN সিনট্যাক্স

BETWEEN vs >= AND <=

BETWEEN

>= AND <=

Numeric BETWEEN

NOT BETWEEN

BETWEEN with Dates / DATETIME

DATETIME সতর্কতা (বিগিনার → প্রো অভ্যাস)

BETWEEN + AND / OR

BETWEEN + AND

BETWEEN + OR (দুই range)

BETWEEN + ORDER BY + LIMIT

BETWEEN + GROUP BY

= / IN / BETWEEN / LIKE / REGEXP

Specific values → IN

Continuous range → BETWEEN

BETWEEN vs WHERE >= <=

E-commerce Business Case Study

Products (নমুনা)

Orders (নমুনা)

Employees (নমুনা)

সমাধান (১১টি প্রশ্ন)

MySQL Workbench Practical

Common Beginner Mistakes

1 — Boundary confusion

2 — Reversing values

3 — Unrelated values

4 — BETWEEN vs IN

5 — DATETIME

6 — Quotes

SQL Execution Flow (simplified)

Industry Use Cases

Performance Tips (beginner)

Interactive Classroom Activities

Mini Project — E-commerce Sales Analysis

BETWEEN Cheat Sheet

MCQ (২০+)

Viva Questions

Interview Top 30

Homework