[SQL/코드카타] 문자열의 길이 세기

1683. Invalid Tweets

 

Table: Tweets

+----------------+---------+
| Column Name    | Type    |
+----------------+---------+
| tweet_id       | int     |
| content        | varchar |
+----------------+---------+
tweet_id is the primary key (column with unique values) for this table.
content consists of alphanumeric characters, '!', or ' ' and no other special characters.
This table contains all the tweets in a social media app.

 

Write a solution to find the IDs of the invalid tweets. The tweet is invalid if the number of characters used in the content of the tweet is strictly greater than 15.

Return the result table in any order.

The result format is in the following example.

 

Example 1:

Input: 
Tweets table:
+----------+-----------------------------------+
| tweet_id | content                           |
+----------+-----------------------------------+
| 1        | Let us Code                       |
| 2        | More than fifteen chars are here! |
+----------+-----------------------------------+
Output: 
+----------+
| tweet_id |
+----------+
| 2        |
+----------+
Explanation: 
Tweet 1 has length = 11. It is a valid tweet.
Tweet 2 has length = 33. It is an invalid tweet.

 

정답 쿼리

select tweet_id
from tweets
where char_length(content) > 15

 

💡 만약 바이트 수를 세고 싶다면! 

length() 함수를 사용