java.sql.SQLException: 未知的系统变量 'query_cache_size'
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java.sql.SQLException: Unknown system variable 'query_cache_size'
提问by Kiên Tr?n Trung
I have a app running with JDBC and get data from MySQL, but I can't build it because of this error :
我有一个使用 JDBC 运行的应用程序并从 MySQL 获取数据，但由于此错误我无法构建它：
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]
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3909) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2527) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2497) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2455) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1369) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3777) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3240) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2249) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2035) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:790) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47) ~[mysql-connector-java-5.1.41.jar:5.1.41]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_131]
I have file application.properties here
我这里有文件 application.properties
#specs.dir=/specs/
#
#################### Spring Boot Data Source Configuration ############
#spring.datasource.driver-class-name=com.mysql.jdbc.Driver
#spring.datasource.url=jdbc:mysql://localhost:3306/savingbooking?useSSL=false
#spring.datasource.username=root
#spring.datasource.password=ZAQ!2wsx
#spring.datasource.initialize=true
#spring.jpa.hibernate.ddl-auto=update
#spring.jpa.properties.hibernate.format_sql=true
#spring.jpa.show-sql=true
#spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQLDialect
Mysql workbench is 8.0 version
Mysql工作台是8.0版本
采纳答案by steven35
回答by ISHAN KUMAR GHOSH
Try using MySQL 8.0.3 As can be seen on the docs, the query_cache_size was removed on MySQL8. JetBrains guys have suffered the same issue, is seems to be that it is fixed by updating the driver to the version MySQL JDBC driver v 5.1.44.
尝试使用 MySQL 8.0.3 从文档中可以看出，MySQL8 上删除了 query_cache_size。JetBrains 的人遇到了同样的问题，似乎是通过将驱动程序更新到 MySQL JDBC 驱动程序 v 5.1.44 版本来修复它。
回答by vineeth sharma
java.sql.SQLException: Unknown system variable 'query_cache_size'
java.sql.SQLException: 未知的系统变量 'query_cache_size'
In pom file of your project, just update the version of the dependency.
在项目的 pom 文件中，只需更新依赖项的版本。
For example it's 6.0.2 of mysql java connector just update it to latest one like 8.0.11
例如，它是 6.0.2 的 mysql java 连接器，只需将其更新为最新版本，例如 8.0.11
It works!!!!
有用！！！！
回答by Asad Shakeel
I had a similar problem. I resolved it by specifying the versionin mysql dependency
我有一个类似的问题。我通过在 mysql 依赖项中指定版本来解决它
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.45</version>
<scope>runtime</scope>
</dependency>
Worked like a charm for me.
对我来说就像一种魅力。
回答by ??ng Ng?c Phong
If you using MySql v8.0 then you should try fix this bug with
如果您使用 MySql v8.0，那么您应该尝试使用以下命令修复此错误
mysql-connector-java-5.1.9
mysql-connector-java-5.1.9
回答by Mukesh Kumar yadav
I stuck on this issue, spend full one day and finally i got solution.
我坚持这个问题，花了整整一天的时间，最后我得到了解决方案。
Solution :
解决方案 ：
1) Use exact mysql-connector-java jar or dependency as your mysql version.
2) if your mysql version is 8 or 6+ try to use this "com.mysql.cj.jdbc.Driver" driver class.
1) 使用确切的 mysql-connector-java jar 或依赖项作为您的 mysql 版本。
2) 如果您的 mysql 版本是 8 或 6+，请尝试使用此“com.mysql.cj.jdbc.Driver”驱动程序类。
回答by Ooguro
Ok so what I did as metioned above. I just added the mysql-connector-java-5.1.4 to build path and ran the project on my server and connected fine to mysql
好的，我按照上面提到的做了什么。我刚刚添加了 mysql-connector-java-5.1.4 来构建路径并在我的服务器上运行该项目并连接到 mysql
回答by Shubham
just change the version of mysql use this in pom.xml
只需更改 mysql 的版本在 pom.xml 中使用它
<version>8.0.11</version>
回答by Enrique Jiménez Flores
For mysql 8:
对于 mysql 8：
mysql-connector-java-8.0.17.jar (or above) + db.driver=com.mysql.cj.jdbc.Driver instead of com.mysql.jdbc.Driver
mysql-connector-java-8.0.17.jar（或更高版本）+ db.driver=com.mysql.cj.jdbc.Driver 而不是 com.mysql.jdbc.Driver
