RENAME COLUMN

Kirish: Ushbu qo'llanmada siz PostgreSQL ALTER TABLE ... RENAME COLUMN buyrug'i yordamida jadval ustuni nomini qanday o'zgartirishni o'rganasiz.

ALTER TABLE RENAME COLUMN buyrug'iga kirish

PostgreSQLda ustun nomini o'zgartirish uchun ALTER TABLE ... RENAME COLUMN buyrug'idan foydalaniladi.

Sintaksis:

ALTER TABLE table_name
RENAME COLUMN column_name TO new_column;

Yozuvni qisqartirish uchun COLUMN so'zini tushirib qoldirish ham mumkin:

ALTER TABLE table_name
RENAME column_name TO new_column;

Agar ustun boshqa obyektlar (ko'rinishlar, tashqi kalitlar, trigirlar) tomonidan ishlatilayotgan bo'lsa, PostgreSQL ushbu obyektlardagi ustun nomlarini ham avtomatik ravishda yangilaydi.

Ustun nomini o'zgartirishga misol

Mijozlardan qaytarilgan mahsulotlarni saqlovchi sales_returns jadvalini yaratamiz:

CREATE TABLE sales_returns (
  id INT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  date DATE NOT NULL,
  product_name VARCHAR(255) NOT NULL,
  quantity INT NOT NULL DEFAULT 1,
  order_id INT,
  reason VARCHAR(255) NOT NULL
);

Endi order_id ustunini sales_order_id ga o'zgartiramiz:

ALTER TABLE sales_returns 
RENAME COLUMN order_id TO sales_order_id;

Ko'rinishga (View) bog'langan ustunni o'zgartirish

Dastlab sales_returns jadvali asosida hisobot ko'rinishini yaratamiz:

CREATE VIEW sales_return_reports AS
SELECT
  product_name,
  date,
  SUM(quantity) AS sum
FROM
  sales_returns
GROUP BY
  product_name,
  date;

Endi asosiy jadvaldagi date ustunini return_date ga o'zgartiramiz:

ALTER TABLE sales_returns 
RENAME COLUMN date TO return_date;

Ko'rinish ta'rifini tekshirganimizda (\d+ sales_return_reports), PostgreSQL ko'rinish ichidagi so'rovni avtomatik yangilaganini ko'rishimiz mumkin:

SELECT product_name,
    return_date AS date,
    sum(quantity) AS sum
FROM sales_returns
GROUP BY product_name, return_date;

Ko'rib turganingizdek, sales_returns jadvalidagi date o'rniga return_date avtomatik yozilgan.

Xulosa

• Jadvaldagi ustun nomini o'zgartirish uchun ALTER TABLE table_name RENAME COLUMN old_name TO new_name; dan foydalaning.
• Bog'langan ko'rinishlar va cheklovlar PostgreSQL tomonidan avtomatik yangilanadi.