问题:
java.sql.SQLException: Unknown system variable 'query_cache_size'
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:545) ~[mysql-connector-java-6.0.6.jar:6.0.6]
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:513) ~[mysql-connector-java-6.0.6.jar:6.0.6]
分析:
pom依赖版本:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>6.0.6</version>
</dependency>
数据库版本:8.0.28
有解释说 :
The query cache is deprecated as of MySQL 5.7.20, and is removed in MySQL 8.0. Deprecation includes query_cache_size.
意思是query cache在MySQL5.7.20已经过时,而在MySQL8.0之后被移除。
解决:
获取支持的依赖(当前最新为8.0.28):
<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.28</version> </dependency>