[๊ฑท๊ธฐ๋ฐ˜] SQL ๋ฌธ๋ฒ• ์—ฐ์Šต 3
ยท
๋‚ด์ผ๋ฐฐ์›€์บ ํ”„/์‚ฌ์ „์บ ํ”„ ๊ณผ์ œ
3) ์ƒํ’ˆ ์ฃผ๋ฌธ์ด ๋“ค์–ด์™”์œผ๋‹ˆ ์ฃผ๋ฌธ์„ ์ฒ˜๋ฆฌํ•ด๋ด…์‹œ๋‹ค![๋ฌธ์ œใ€€ใ€€๋‚ด๊ฐ€ ์“ด ๋‹ตใ€€ใ€€์บ ํ”„์—์„œ ์ œ๊ณตํ•œ ๋‹ต์•ˆใ€€ใ€€- ์˜ค๋‹ต๋…ธํŠธ ๋ฐ ์˜๋ฌธ์‚ฌํ•ญ] 9. orders ํ…Œ์ด๋ธ”์—์„œ ์ฃผ๋ฌธ ์ˆ˜๋Ÿ‰(amount)์ด 2๊ฐœ ์ด์ƒ์ธ ์ฃผ๋ฌธ์„ ์ง„ํ–‰ํ•œ ์†Œ๋น„์ž์˜ ID(customer_id)๋งŒ ์„ ํƒํ•˜๋Š” ์ฟผ๋ฆฌ๋ฅผ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”!ใ€€ใ€€SELECT id FROM orders WHERE amount>=2; ใ€€ใ€€=> SELECT customer_id FROM orders WHERE amount > 1;ใ€€ใ€€- '>=' ๋˜๋Š” 'ใ€€ใ€€-  ๊ทผ๋ฐ ์™œ ๋ฌธ์ œ๋Š” 2๊ฐœ  ์ด์ƒ์ธ๋ฐ ์ •๋‹ต์€ >1๋กœ ํ‘œํ˜„ํ–ˆ์„๊นŒ? ์–ด์ฐจํ”ผ ์ˆ˜๋Ÿ‰์ด๋‹ˆ๊นŒ ๋ชจ๋‘ ์ •์ˆ˜๋ผ์„œ? ๊ทธ๋ž˜๋„ 2 ์ด์ƒ์ธ๋ฐ 1์ดˆ๊ณผ๋กœ ํ‘œํ˜„ํ•œ ์ด์œ ๊ฐ€ ๋”ฐ๋กœ ์žˆ๋Š”์ง€ ๊ถ๊ธˆํ•˜๋‹ค.ใ€€ใ€€- customer_id์™€ id ๋‘๊ฐœ์ด ์†์„ฑ์ด ์žˆ์—ˆ๋‹ค.. ์ž˜ ๊ตฌ๋ถ„ํ•ด์„œ ์ž‘์„ฑํ•˜๊ธฐใ€€..
[๊ฑท๊ธฐ๋ฐ˜] SQL ๋ฌธ๋ฒ• ์—ฐ์Šต 2
ยท
๋‚ด์ผ๋ฐฐ์›€์บ ํ”„/์‚ฌ์ „์บ ํ”„ ๊ณผ์ œ
2) ์ด์ œ ์ข€ ๋ฒŒ์—ˆ์œผ๋‹ˆ flexํ•œ ๋ฒˆ ํ•ด๋ณผ๊นŒ์š”?! 5. products ํ…Œ์ด๋ธ”์—์„œ ์ œํ’ˆ ์ด๋ฆ„(product_name)๊ณผ ๊ฐ€๊ฒฉ(price)๋งŒ์„ ์„ ํƒํ•˜๋Š” ์ฟผ๋ฆฌ๋ฅผ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”.ใ€€ ใ€€SELECT product_name, price FROM products;6.products ํ…Œ์ด๋ธ”์—์„œ ์ œํ’ˆ ์ด๋ฆ„์— 'ํ”„๋กœ'๊ฐ€ ํฌํ•จ๋œ ๋ชจ๋“  ์ œํ’ˆ์„ ์„ ํƒํ•˜๋Š” ์ฟผ๋ฆฌ๋ฅผ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”.ใ€€ ใ€€ SELECT  id, product_name, price, category FROM products WHERE product_name LIKE '%ํ”„๋กœ%';7. products ํ…Œ์ด๋ธ”์—์„œ ์ œํ’ˆ ์ด๋ฆ„์ด '๊ฐค'๋กœ ์‹œ์ž‘ํ•˜๋Š” ๋ชจ๋“  ์ œํ’ˆ์„ ์„ ํƒํ•˜๋Š” ์ฟผ๋ฆฌ๋ฅผ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”.ใ€€ ใ€€ SELECT  id, product_name, price, category FROM pr..
[๊ฑท๊ธฐ๋ฐ˜] SQL ๋ฌธ๋ฒ• ์—ฐ์Šต 1
ยท
๋‚ด์ผ๋ฐฐ์›€์บ ํ”„/์‚ฌ์ „์บ ํ”„ ๊ณผ์ œ
1) ๋ˆ์„ ๋ฒŒ๊ธฐ ์œ„ํ•ด ์ผ์„ ํ•ฉ์‹œ๋‹ค! 1. sparta_employees ํ…Œ์ด๋ธ”์—์„œ ๋ชจ๋“  ์ง์›์˜ ์ด๋ฆ„(name)๊ณผ ์ง๊ธ‰(position)์„ ์„ ํƒํ•˜๋Š” ์ฟผ๋ฆฌ๋ฅผ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”.ใ€€ใ€€SELECT name, position From sparta_employees;2. sparta_employees ํ…Œ์ด๋ธ”์—์„œ ์ค‘๋ณต ์—†์ด ๋ชจ๋“  ์ง๊ธ‰(position)์„ ์„ ํƒํ•˜๋Š” ์ฟผ๋ฆฌ๋ฅผ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”.ใ€€ใ€€SELECT DISTINCT position From sparta_employees;3. sparta_employees ํ…Œ์ด๋ธ”์—์„œ ์—ฐ๋ด‰(salary)์ด 40000๊ณผ 60000 ์‚ฌ์ด์ธ ์ง์›๋“ค์„ ์„ ํƒํ•˜๋Š” ์ฟผ๋ฆฌ๋ฅผ ์ž‘์„ฑํ•ด์ฃผ์„ธ์š”.ใ€€ใ€€SELECT salary From sparta_employees Where salary > 40000 AND salary..