Laboratoriya mashg’ulotlari materiallari 1 Laboratoriya ishi Mavzu: Ma`lumotlar bazasini loyihalash. Mohiyat – aloqa diagrammasini qurish (er modeli). Ishdan maqsad

SELECT * FROM `mahsulotlar` WHERE `mah_narxi(so``m)` BETWEEN 500 AND 2000;

4.1 rasm. 1 misoldagi so`rovning natijasi

2. 
   Mahsulotlar soni sanalsin.
   

SELECT count(*) as `mahsulot soni` FROM `mahsulotlar`;

4.2 rasm. 2 misoldagi so`rovning natijasi

3. 
   Eng yuqori narxga ega bo`lgan mahsulot narxi chiqarilsin.
   

SELECT MAX(`mah_narxi(so``m)`) as `eng qimmat mahsulot` FROM `mahsulotlar`;

4.3 rasm. 3 misoldagi so`rovning natijasi

4. 
   Eng arzon bo`lgan mahsulot haqida ma`lumot chiqarilsin.
   

SELECT * FROM `mahsulotlar` WHERE `mah_narxi(so``m)`=(SELECT MIN(`mah_narxi(so``m)`) FROM `mahsulotlar`);

4.4 rasm. 4 misoldagi so`rovning natijasi

5. 
   Mahsulotlar narxlarining o`rta arifmetigi topilsin.
   

SELECT AVG(`mah_narxi(so``m)`) as `o``rtacha arifmetigi` FROM `mahsulotlar`;

4.5 rasm. 5 misoldagi so`rovning natijasi

6. 
   Sut mahsuloti haqida ma`lumot chiqarilsin.
   

SELECT * FROM `mahsulotlar` WHERE `mahsulot_nomi`='Sut';

4.6 rasm. 6 misoldagi so`rovning natijasi

7. 
   Birinchi xodim manzili haqida ma`lumot berilsin.
   

SELECT * FROM `xodimlar` WHERE `x_id`=1;

4.7 rasm. 7 misoldagi so`rovning natijasi

8. 
   Barcha xodimlarni bir oylik maoshlarini yig`indisini topish.
   

SELECT SUM(`maoshi`) as `maoshlar yi``gindisi` FROM `xodimlar`;

4.8 rasm. 8 misoldagi so`rovning natijasi

9. 
   Xodimlar familyalarining bosh harflari chiqarilsin.
   

a) SELECT MID(`familiya`,1,1) as `bosh harflari` FROM `xodimlar`;
b) SELECT LEFT(`familiya`,1) as `bosh harflari` FROM `xodimlar`;
c) SELECT SUBSTR(`familiya`,1,1) as `bosh harflari` FROM `xodimlar`;