idea数据库遇到的问题

1.时区问题

      （1）  Caused by: com.mysql.cj.exceptions.InvalidConnectionAttributeException: The server time zone value 'Öйú±ê׼ʱ¼ä' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.

      （2） Connection to spring@localhost failed. [08001] Could not create connection to database server. Attempted reconnect 3 times. Giving up. 

解决方法：在数据库url后加上    “?serverTimezone=GMT”

<!--数据库url-->
<property name="url" value="jdbc:mysql://localhost/spring?serverTimezone=GMT" />

2.版本问题,版本太低

  (1)   Unknown system variable 'tx_read_only'

（2）Unknown system variable 'query_cache_size'   

解决方法：将版本升为8.0.11

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