CONCAT

Kirish: ushbu darsda siz bir nechta satrlarni bitta satrga birlashtirish uchun PostgreSQL CONCAT() funksiyasi, CONCAT_WS() funksiyasi va birlashtirish operatori (||) dan qanday foydalanishni o'rganasiz.

PostgreSQL || birlashtirish operatori

Ikki satrni bitta satrga birlashtirish uchun || birlashtirish operatoridan foydalaniladi:

s1 || s2

Masalan, quyidagi SELECT so'rovi inventories jadvalidan mahsulot nomi va brendni olib, ularni bitta satrga birlashtiradi:

SELECT
  brand || name AS product
FROM
  inventories;

Natija:

product
-------------------------
 AppleiPhone 14 Pro
 SamsungGalaxy S23 Ultra
 GooglePixel 7 Pro
 SonyXperia 1 IV

Ma'lumotni o'qilishi qulay bo'lishi uchun satrlar orasiga bo'shliq qo'shish mumkin:

SELECT
  brand || ' ' || name AS product
FROM
  inventories;

Natija:

product
--------------------------
 Apple iPhone 14 Pro
 Samsung Galaxy S23 Ultra
 Google Pixel 7 Pro
 Sony Xperia 1 IV

CONCAT funksiyasi

Birlashtirish operatoridan tashqari, PostgreSQL bir nechta satrlarni bitta satrga birlashtiruvchi CONCAT() funksiyasini ham taqdim etadi:

CONCAT(s1, s2, ...)

Masalan, brand ustunidagi satrlar, bo'shliq va name ustunidagi satrlarni bitta satrga birlashtirish mumkin:

SELECT
  CONCAT(brand, ' ', name) AS product
FROM
  inventories;

Natija:

product
--------------------------
 Apple iPhone 14 Pro
 Samsung Galaxy S23 Ultra
 Google Pixel 7 Pro
 Sony Xperia 1 IV

CONCAT_WS: Ajratuvchi bilan satrlarni birlashtirish

Satrlarni ajratuvchi bilan birlashtirish uchun quyidagi sintaksis bilan CONCAT_WS() funksiyasidan foydalaniladi:

CONCAT_WS(separator, s1, s2, ..)

E'tibor bering, WS — With Separator (Ajratuvchi bilan) degan ma'noni anglatadi.

Masalan, quyidagi so'rov CONCAT_WS() funksiyasidan foydalanib, brand va name ni bo'shliq ajratuvchi bilan birlashtiradi:

SELECT
  CONCAT_WS(' ', brand, name) AS product
FROM
  inventories;

Natija:

product
--------------------------
 Apple iPhone 14 Pro
 Samsung Galaxy S23 Ultra
 Google Pixel 7 Pro
 Sony Xperia 1 IV

Xulosa

• Ikki satrni bitta satrga birlashtirish uchun || birlashtirish operatoridan foydalaning.
• Ikki yoki undan ortiq satrlarni bitta satrga birlashtirish uchun CONCAT() funksiyasidan foydalaning.
• Ikki yoki undan ortiq satrlarni ajratuvchi bilan bitta satrga birlashtirish uchun CONCAT_WS() funksiyasidan foydalaning.