Fix Names in a Table using CONCAT and CONCAT WS SQL MySQL leetcode solution
Fix Names in a Table using CONCAT and CONCAT WS SQL MySQL leetcode solution
This query aims to format the names in the Users table. Specifically, it capitalizes the first letter of each name and makes all other letters lowercase.
Query Explanation:
sql
Copy code
SELECT
user_id,
CONCAT_WS('',
UPPER(SUBSTR(name, 1, 1)),
LOWER(SUBSTR(name, 2))) name
FROM
Users;
SELECT user_id: This selects the user_id column from the Users table.
CONCAT_WS('', ...): This is a function that concatenates strings with a separator. Here, the separator is an empty string (''), meaning the strings will be concatenated directly without any separator.
UPPER(SUBSTR(name, 1, 1)):
SUBSTR(name, 1, 1): Extracts the first character of the name.
UPPER(...): Converts this first character to uppercase.
LOWER(SUBSTR(name, 2)):
SUBSTR(name, 2): Extracts the substring of name starting from the second character to the end.
LOWER(...): Converts this substring to lowercase.
name: This renames the result of the concatenation to name in the output.
FROM Users: This specifies that the data is being selected from the Users table.
CONCAT Example
This example demonstrates the usage of the CONCAT function to concatenate multiple strings with no separators.
Query Explanation:
sql
Copy code
SELECT CONCAT('Hello', ' ', 'World', ' ', 'youtube') AS result;
CONCAT('Hello', ' ', 'World', ' ', 'youtube'):
This function concatenates the provided strings ('Hello', ' ', 'World', ' ', 'youtube') into a single string.
The result is 'Hello World youtube'.
AS result: This names the output column as result.
CONCAT_WS Example
This example demonstrates the usage of the CONCAT_WS function, which concatenates multiple strings with a specified separator.
Query Explanation:
sql
Copy code
SELECT CONCAT_WS(' ', 'Hello', 'World', 'youtube') AS result;
CONCAT_WS(' ', 'Hello', 'World', 'youtube'):
CONCAT_WS(' ', ...): This function concatenates the provided strings with a space (' ') as the separator.
The result is 'Hello World youtube'.
AS result: This names the output column as result.
Summary
The first query formats names in the Users table by capitalizing the first letter and making all other letters lowercase using CONCAT_WS, UPPER, and LOWER functions.
The second query shows a basic use of the CONCAT function to join multiple strings with no specific separator.
The third query demonstrates the CONCAT_WS function, which joins multiple strings with a specified separator.
Смотрите видео Fix Names in a Table using CONCAT and CONCAT WS SQL MySQL leetcode solution онлайн, длительностью часов минут секунд в хорошем качестве, которое загружено на канал CodeWis Technologies by Nuhman Paramban 03 Июнь 2024. Делитесь ссылкой на видео в социальных сетях, чтобы ваши подписчики и друзья так же посмотрели это видео. Данный видеоклип посмотрели 13 раз и оно понравилось 1 посетителям.
