「SQL面试题库」 No_122 Fix Product Name Format

今日真题

题目介绍： Fix Product Name Format fix-product-name-format

难度简单

SQL架构

Table:

Sales

+--------------+---------+
| Column Name  | Type    |
+--------------+---------+
| sale_id      | int     |
| product_name | varchar |
| sale_date    | date    |
+--------------+---------+
sale_id is the primary key for this table.
Each row of this table contains the product name and the date it was sold.

Since table Sales was filled manually in the year 2000,

product_name

may contain leading and/or trailing white spaces, also they are case-insensitive.

Write an SQL query to report

product_name

in lowercase without leading or trailing white spaces.

sale_date

in the format

('YYYY-MM')

total

the number of times the product was sold in this month.

Return the result table ordered by

product_name

in ascending order, in case of a tie order it by

sale_date

in ascending order.

The query result format is in the following example.

``` Sales +------------+------------------+--------------+ | sale_id | product_name | sale_date | +------------+------------------+--------------+ | 1 | LCPHONE | 2000-01-16 | | 2 | LCPhone | 2000-01-17 | | 3 | LcPhOnE | 2000-02-18 | | 4 | LCKeyCHAiN | 2000-02-19 | | 5 | LCKeyChain | 2000-02-28 | | 6 | Matryoshka | 2000-03-31 | +------------+------------------+--------------+

Result table: +--------------+--------------+----------+ | product_name | sale_date | total | +--------------+--------------+----------+ | lcphone | 2000-01 | 2 | | lckeychain | 2000-02 | 2 | | lcphone | 2000-02 | 1 | | matryoshka | 2000-03 | 1 | +--------------+--------------+----------+

In January, 2 LcPhones were sold, please note that the product names are not case sensitive and may contain spaces. In Februery, 2 LCKeychains and 1 LCPhone were sold. In March, 1 matryoshka was sold. ```

sql
select trim(lower(product_name)) as product_name, 
        date_format(sale_date,'%Y-%m') as sale_date,
        count(*) as total 
from Sales 
group by trim(lower(product_name)), date_format(sale_date,'%Y-%m') 
order by product_name asc, sale_date asc

注意大小写、空格

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