mysql存储emoji表情报错的处理方法【更改编码为utf8mb4】
mysql存储emoji表情报错的处理方法【更改编码为utf8mb4】
项目需要存储微信用户的昵称，由于部分微信用户昵称带有表情，数据库保存会报错
java.sql.SQLException: Incorrect string value: '\xF0\x9F\x92\x94' for column 'name' at row 1
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1073)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3593)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3525)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1986)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2140)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2620)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1662)
at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1581)
这是由于tf-8编码可能2个字节、3个字节、4个字节的字符，但是MySQL的utf8编码只支持3字节的数据，而移动端的表情数据是4个字节的字符。如果直接往采用utf-8编码的数据库中插入表情数据，Java程序中将报SQL异常：
具体修改如下
可以对4字节的字符进行编码存储，然后取出来的时候，再进行解码。但是这样做会使得任何使用该字符
的地方都要进行编码与解码。
utf8mb4编码是utf8编码的超集，兼容utf8，并且能存储4字节的表情字符。
采用utf8mb4编码的好处是：存储与获取数据的时候，不用再考虑表情字符的编码与解码问题。
更改数据库的编码为utf8mb4:
- MySQL的版本
utf8mb4的最低mysql版本支持版本为5.5.3+，若不是，请升级到较新版本。
- MySQL驱动（项目中的jar包版本）5.1.34可用,最低不能低于5.1.13
- mysql-connector-java-5.1.45.jar
3.修改MySQL配置文件
修改mysql配置文件my.cnf（windows为my.ini）
my.cnf一般在etc/mysql/my.cnf位置。找到后请在以下三部分里添加如下内容：
[client]
default-character-set = utf8mb4
[mysql]
default-character-set = utf8mb4
[mysqld]
character-set-client-handshake = FALSE
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect='SET NAMES utf8mb4'
- 重启数据库，检查变量
5. `SHOW VARIABLES WHERE Variable_name LIKE 'character_set_%' OR Variable_name LIKE 'collation%';`
collation_connection 、collation_database 、collation_server是什么没关系。
但必须保证
这几个变量必须是utf8mb4。
5. 数据库连接的配置
数据库连接参数中:
characterEncoding=utf8会被自动识别为utf8mb4，也可以不加这个参数，会自动检测。
而autoReconnect=true是必须加上的。
6. 将数据库和已经建好的表也转换成utf8mb4
更改数据库编码：
ALTER DATABASE `data_name` CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;
更改表编码：
ALTER TABLE TABLE_NAME CONVERT TO CHARACTER SET utf8mb4 COLLATEutf8mb4_general_ci;
7、在第3步设置character_set_database，character_set_server不成功的可以试下直接在mysql.exe下
set @@character_set_server='utf8mb4';
set @@character_set_database='utf8mb4';
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.
[client]
default-character-set = utf8mb4
[mysql]
default-character-set = utf8mb4
[mysqld]
character-set-client-handshake = FALSE
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci
init_connect='SET NAMES utf8mb4'
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
# These are commonly set, remove the # and set as required.
# basedir = .....
# datadir = .....
# port = .....
# server_id = .....
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
非常感谢原博主！！