java.sql.SQLException：未知的系统变量'query_cache_size'

java mysql jdbc spring-boot

2022-09-01 02:46:45

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]

我在这里有文件应用程序.属性

#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 工作台是 8.0 版本

答案 1

query_cache_size在 MySQL 8 中被删除。查看文档。

它与 JDBC 驱动程序 5.1.44 配合使用。

答案 2

java.sql.SQLException：未知的系统变量'query_cache_size'

在项目的 pom 文件中，只需更新依赖项的版本即可。

例如，它是6.0.2的mysql java连接器，只需将其更新为最新的8.0.11

它的工作原理!!!!