Data definition language) Ma`lumotlarni manipulyatsiya qilish tili

Simple integrity constraint types

Integrity constraint can be divided into the following types:

• PRIMARY KEY
• UNIQUE
• NULL/NOT NULL
• FOREIGN KEY/REFERENCE
• CHECK

Masalalar

• Imtihon jadvalidan baholar sonini aniqlang.
• Fanlar jadvalidan fanlar sonini aniqlang.
• Imtihon jadvalidan eng yuqori baho olgan talaba va 34 soatga teng bo’lgan fanlarni guruhlang.
• Mahsulot jadvalidan mahsulot narxi 500 va 2000 oralig’idagi narxlarni chiqaring.
• Mahsulot jadvalidan eng qimmat mahsulotni aniqlang.
• Mahsulotlar jadvalidan mahsulot narxini o’rtacha qiymatini toping.
• Mahsulot jadvalidan yo’nalishi go’shtga tenglarini aniqlang.
• Mahsulot jadvalidan id si 2 ga teng bo’lmagan va narxi 500 va 2000 oralig’idagi mahsulotlarni aniqlang.

Masalalar

• Select count(*) from EXAMS_MARKS ;
• Select count(subj_ID) from SUBJECT;
• Select student_ID, Max(mark) from EXAM_MARKS Group by Subj_name Having max (Hour)>= 34;
• select * from Mahsulotlar where [mahsulot narxi] BETWEEN 500 AND 2000);
• select Max([Mahsulot narxi]) AS [eng qimmat mahsulot narxi] from Mahsulotlar;
• select AVG([Mahsulot narxi]) from mahsulotlar;
• select * from Mahsulotlar where Yunalishlar IN (Gusht);
• select * from Mahsulotlar where [mahsulot narxi] BETWEEN 500 AND 2000) AND NOT Mahsulot_t_id IN (2);