Solve the error string value: '\xf0\x9f\x98\xad',... 'for column' commentcontent 'at row 1

demand : analysis excel form , take excel Insert the data in the database

        There is such a problem when inserting data into the database :

### Cause: java.sql.SQLException: Incorrect string value: '\xF0\x9F\x90\xB1\xF0\x9F...' for column 'describe' at row 1
; uncategorized SQLException; SQL state [HY000]; error code [1366]; Incorrect string value: '\xF0\x9F\x90\xB1\xF0\x9F...' for column 'describe' at row 1; nested exception is java.sql.SQLException: Incorrect string value: '\xF0\x9F\x90\xB1\xF0\x9F...' for column 'describe' at row 1

         What is outrageous is actually the front of the parsing table 300 This error does not appear in line , In the first 301 It's time to report sql abnormal . The first thing I think about is whether it will be 301 Will the row data have a special format , It turned out that there was no , But the data content is different , There is no special format , Checked for half an hour , The result is that the database is incorrectly encoded .

         The reason is that some of our tabular data have been parsed into expressions , These expressions are encoded in four bytes and one unit , And what we usually use utf-8 Encoding in mysql The default in the database is 3 One byte, one unit , It is for this reason that data is stored mysql There was an error in the database .

I divide it into the following three steps to solve ：

        (1)、 see mysql Coding of database

show variables like 'character_set_database';

        If it is urf8 Need to change to uft8mb4

        (2)、 Modify the code of the data table to utf8mb4

ALTER TABLE TABLE_NAME CONVERT TO CHARACTER SET utf8mb4;

                You can also directly use the graphical interface to change

        (3)、 Modify the connection code to connect to the database

         jdbc:mysql://localhost:3824/reggie?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf-8
  It is amended as follows :
         jdbc:mysql://localhost/reggie