Sql tilida index yaratish. Tasavvur, view yaratish va undan foydalanish

Funksya yaratish 
mysql> Create function 
sotuvchilar()
-> returns varchar(20)
-> deterministic
-> begin
-> declare result VARCHAR(30) ;
-> SET RESULT = 'sotuvchilar' ;
-> RETURN (RESULT);
-> end $$
Query OK, 0 rows affected (0.05 sec)
mysql> select sotuvchilar() $$
+----------+
| sotuvchilar() |
+----------+
| sotuvchilar |
+----------+
1 row in set (0.03 sec)
 
 
 

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use oziq_ovqa_savdo_dokoni 
$$ Database changed mysql> 
create table buyurtma
-> ( id int auto_increment primary key,
-> berilgan_vaqt date,
-> yetib_borish_vaqti date,
-> nomi text ) $$
Query OK, 0 rows affected (0.11 sec)
mysql> create trigger j_vaqti before insert
-> on
-> buyurtma
-> for each row
-> begin
-> set new.berilgan_vaqt=now();
-> set new.yetib_borish_vaqti=adddate(new.berilgan_vaqt, 
interval 1 day); -> end $$
Query OK, 0 rows affected (0.13 sec)
Records: 4 Duplicates: 0 Warnings: 4

---

mysql> select * from buyurtma $$
+----+---------------+--------------------+-----------+
| id | berilgan_vaqt | yetib_borish_vaqti | nomi |
+----+---------------+--------------------+-----------+
| 1 | 2022-12-14 | 2022-12-15 | Patir |
| 2 | 2022-12-14 | 2022-12-15 | buxonka |
| 3 | 2022-12-14 | 2022-12-15 | bolichka |
| 4 | 2022-12-14 | 2022-12-15 | Oddiy non |
+----+---------------+--------------------+-----------+
4 rows in set (0.02 sec)
mysql> show triggers\G $$
*************************** 1. row ***************************
Trigger: j_vaqti
Event: INSERT
Table: buyurtma Statement: begin set 
new.berilgan_vaqt=now(); set 

---

new.yetib_borish_vaqti=adddate(new.berilgan_vaqt, interval 
1 day); end
Timing: BEFORE
Created: NULL
sql_mode:
STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_ENGINE_SUBST
ITUTION
Definer: root@localhost 
character_set_client: latin1 
collation_connection: latin1_swedish_ci
Database Collation: latin1_swedish_ci 1 
row in set (0.02 sec)
Xulosa
Men bu SQL tili orqali non markazi haqida dastur tuzdim kelajakda buni 
takomillashtirilsa non markazidagilar uchun qulaylik vaqtni tejash uchun judayam 
foydali bo’ladi degan umiddaman.

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