Niuke.com's SQL must know (1) - string interception, splicing, letter case

knowledge points

Keywords: substing, concat, upper

usage:

• String interception: substring(string, starting position, number of intercepted characters)

• String concatenation: concat(string 1, string 2, string 3,...)

• Letter capitalization: upper(string)

• Lowercase letters: lower(string)

Products表

prod_name	prod_desc
a0011	usb
a0019	iphone13
b0019	gucci t-shirts
c0019	gucci toy
d0019	lego toy carrots

[Question] Write an SQL statement to retrieve the product name (prod_name) and description (prod_desc) from the Products table, and only return the products in which toy and carrots appear in the description in sequence. Tip: Just use LIKE with three % signs.

select prod_name,
        prod_desc
from Products
where prod_desc like '%toy%carrots%'

[Example result] return product name and product description

prod_name	prod_desc
d0019	lego toy carrots

81. Return the customer ID (cust_id), customer name (cust_name) and login name (user_login), where the login name is all capital letters, and consists of the first two characters of the customer contact (cust_contact) and the first three characters of the city where it is located characters (cust_city). Hint: Functions, concatenation, and aliases are required.

Given the Customers table as follows:

cust_id	cust_name	cust_contact	cust_city
a1	Andy Li	Andy Li	Oak Park
a2	Ben Liu	Ben Liu	Oak Park
a3	Tony Dai	Tony Dai	Oak Park
a4	Tom Chen	Tom Chen	Oak Park
a5	An Li	An Li	Oak Park
a6	Lee Chen	Lee Chen	Oak Park
a7	Hex Liu	Hex Liu	Oak Park

select
  cust_id,
  cust_name,
  upper(concat(substring(cust_name, 1, 2),substring(cust_city, 1, 3))) as user_login
from
  Customers

【Example result】

Return customer id cust_id, customer name cust_name, customer login name user_login

cust_id	cust_name	user_login
a1	Andy Li	rations
a2	Ben Liu	LIGHTS
a3	Tony Dai	TOOAK
a4	Tom Chen	TOOAK
a5	An Li	rations
a6	Lee Chen	THE LIONS
a7	Hex Liu	THE HEAT