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

Question

I have a app running with JDBC and get data from MySQL, but I can't build it because of this error :

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

#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

Answer 1

query_cache_size was removed in MySQL 8. Check the docs .

It works with JDBC driver 5.1.44.

Answer 2

java.sql.SQLException: Unknown system variable 'query_cache_size'

In pom file of your project, just update the version of the dependency.

For example it's 6.0.2 of mysql java connector just update it to latest one like 8.0.11

It works!!!!

Answer 3

I had a similar problem. I resolved it by specifying the version in mysql dependency

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.45</version>
    <scope>runtime</scope>
</dependency>

Worked like a charm for me.

Answer 4

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.

Answer 5

For mysql 8:

mysql-connector-java-8.0.17.jar (or above) + db.driver=com.mysql.cj.jdbc.Driver instead of com.mysql.jdbc.Driver

Answer 6

If you using MySql v8.0 then you should try fix this bug with

mysql-connector-java-5.1.9

Answer 7

I stuck on this issue, spend full one day and finally i got solution.

Solution :

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.

Answer 8

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

Answer 9

This exception is related to pom.xml dependency. When I use below dependency in pox.xml:

 <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>6.0.5</version>
 </dependency>

It shows exception:Caused by: java.sql.SQLException: Unknown system variable query_cache_size

But, when I use below dependency:

  <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
  </dependency>

It works.You have to use latest dependency

Answer 10

只需更改 mysql 的版本在 pom.xml 中使用它

<version>8.0.11</version>

Answer 11

Use Below mention dependency it will work for you!

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.16</version>
    </dependency>