mysql版本8.0.11

java連線mysql 報錯

java.sql.SQLException: Unknown system variable 'query_cache_size' at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:545) at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:513) at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:115) at com.mysql.cj.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:1983) at com.mysql.cj.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:1936) at com.mysql.cj.jdbc.StatementImpl.executeQuery(StatementImpl.java:1422) at com.mysql.cj.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:2831) at com.mysql.cj.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:2381) at com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:1739) at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:1596) at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:633) at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:347) at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:219) at java.sql.DriverManager.getConnection(DriverManager.java:664) at java.sql.DriverManager.getConnection(DriverManager.java:270)

原因是mysql-connector-java的版本還是6.0.6，需要升級版本到8.0.11 ，這個報錯就不存在了

<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.11</version> </dependency>

此方法同樣適用於gradle