Mavzu: Маълумотларни бошқариш тили операторларидан (insert, select, update, delete) фойдаланиб оддий сўровларни яратишга оид мисоллар

Mavzu: Маълумотларни бошқариш тили операторларидан (INSERT, SELECT, UPDATE, DELETE) фойдаланиб оддий сўровларни яратишга оид мисоллар.

• MySQL Workbenchda INSERT kalit so’zlaridan foydalanish;
• MySQL Workbenchda SELECT kalit so’zlaridan foydalanish;
• MySQL Workbenchda UPDATE kalit so’zlaridan foydalanish;
• MySQL Workbenchda DELETE kalit so’zlaridan foydalanish;

Jadvalga ma’lumot kiritish

• INSERT INTO [(,...)]
• {VALUES (,…)}
• |
• | {DEFAULT VALUES}

• CREATE TABLE product
• (
• maker char (1) NOT NULL,
• model varchar (4) NOT NULL,
• type varchar (7) NOT NULL
• );

Masalan: jadval yartish

• INSERT INTO Product
• VALUES ('B', 1157, 'PC');

Yoki:
INSERT INTO Product (type, model, maker)
VALUES ('PC', 1157, 'B');

Jadvalga ma’lumot qo’shish

Misollar:

Jadvaldagi hamma ustunlarni tanlah:
mysql> SELECT * FROM worker
Jadvaldagi kerakli ustunlarni tanlash:
mysql> SELECT name, salary FROM worker;
Ikkita virtual jadvaldan foydalanish:
mysql> SELECT 2+3 FROM DUAL;
Joriy vaqt va sanani ko’rish:
mysql> SELECT NOW() FROM DUAL;
WHERE shartli bilan birgalikda qo’llash
worker jadvalidagi salary ustunining 600 dan kata qiymatlarini chiqarish (shu bilan bir qatorda <,>=,<=,!= ishlatilish mumkin)
mysql> SELECT * FROM worker WHERE salary > 6000;
worker jadvalidagi dept ustining faqat “IT” so’zi qatnashganlarni chiqarish:
mysql> SELECT * FROM worker WHERE dept = 'IT';
worker jad. name ustunidagi “Ab” deb boshlangan so’zarni chiqarish:
mysql> SELECT * FROM worker WHERE name LIKE 'Ab%';
Jadvaldagi bir nechta ustunlarni birlashtirish:
mysql> SELECT ID, CONCAT(NAME, ' FROM ', DEPT) AS NAME, SALARY FROM worker;
+-----+------------------------+--------+
| id | name | salary |
+-----+------------------------+--------+
| 100 | AndreyEx from Sales | 5000 |
| 200 | Boris from IT | 5500 |
| 300 | Anna from IT | 7000 |
| 400 | Anton from Marketing | 9500 |
| 500 | Dima from IT | 6000 |
| 501 | Maxs from Accounting | NULL |
+-----+------------------------+--------+
6 rows in set (0.00 sec)
Jadvaldagi yozuvlar sonini ko’rish:
mysql> SELECT COUNT(*) FROM worker;