java.sql.SQLException: Unknown system variable '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         


        

Answer 1

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 2

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 3

query_cache_size was removed in MySQL 8. Check the docs.

It works with JDBC driver 5.1.44.

Answer 4

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 5

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 6

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