“Incorrect string value” when trying to insert UTF-8 into MySQL via JDBC?

Question

This is how my connection is set:
Connection conn = DriverManager.getConnection(url + dbName + \"?useUnicode=true&characterEncoding=utf-8\", userName, password

Answer 1

I had the same problem in my rails project:

Incorrect string value: '\xF0\xA9\xB8\xBDs ...' for column 'subject' at row1

Solution 1: before saving to db convert string to base64 by Base64.encode64(subject) and after fetching from db use Base64.decode64(subject)

Solution 2:

Step 1: Change the character set (and collation) for subject column by

ALTER TABLE t1 MODIFY
subject VARCHAR(255)
  CHARACTER SET utf8mb4
  COLLATE utf8mb4_unicode_ci;

Step 2: In database.yml use

encoding :utf8mb4