大家好，我正在尝试将Spring boot App与Mysql连接，但不幸的是，它不起作用。 application.properties文件：
spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=root
spring.datasource.password=*********
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
# Keep the connection alive if idle for a long time (needed in production)
spring.datasource.tomcat.max-active=1
# ===============================
# = JPA / HIBERNATE
# ===============================
# Use spring.jpa.properties.* for Hibernate native properties (the prefix is
# stripped before adding them to the entity manager).
# Show or not log for each sql query
spring.jpa.show-sql = true
# Hibernate ddl auto (create, create-drop, update): with "update" the database
# schema will be automatically updated accordingly to java entities found in
# the project
spring.jpa.hibernate.ddl-auto = update
# Allows Hibernate to generate SQL optimized for a particular DBMS
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5Dialect
我得到的错误如下：
2018-07-06 18:32:10.832 WARN 7180 --- [ main] o.a.tomcat.jdbc.pool.ConnectionPool : maxIdle is larger than maxActive, setting maxIdle to: 1
Fri Jul 06 18:32:10 CEST 2018 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
2018-07-06 18:32:11.093 ERROR 7180 --- [ main] o.a.tomcat.jdbc.pool.ConnectionPool : Unable to create initial connections of pool.
java.sql.SQLException: Unknown system variable 'query_cache_size'
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:964) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.auth0.samples.bootfaces.Application.main(Application.java:21) [classes/:na]
2018-07-06 18:32:11.109 WARN 7180 --- [ main] ationConfigEmbeddedWebApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Invocation of init method failed; nested exception is org.flywaydb.core.api.FlywayException: Unable to obtain Jdbc connection from DataSource
Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2018-07-06 18:32:11.176 ERROR 7180 --- [ main] o.s.boot.SpringApplication : Application startup failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: Invocation of init method failed; nested exception is org.flywaydb.core.api.FlywayException: Unable to obtain Jdbc connection from DataSource
Caused by: org.flywaydb.core.api.FlywayException: Unable to obtain Jdbc connection from DataSource
at org.flywaydb.core.internal.util.jdbc.JdbcUtils.openConnection(JdbcUtils.java:56) ~[flyway-core-3.2.1.jar:na]
pport.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.7.RELEASE.jar:4.3.7.RELEASE]
... 18 common frames omitted
Caused by: java.sql.SQLException: Unknown system variable 'query_cache_size'
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:964) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3973) ~[mysql-connector-java-5.1.41.jar:5.1.41]