mysql8.0查询报错：java.sql.SQLException: Cannot determine value type from string ‘id‘ Query

﹏ヽ暗。殇╰゛Y 2022-12-30 13:55 134阅读 0赞

### 报错信息： ###

十二月 26, 2020 8:03:30 上午 com.alibaba.druid.pool.DruidDataSource info
    信息: { dataSource-1} inited
    java.sql.SQLException: Cannot determine value type from string 'id' Query: select 'id','username','password','email' from t_user where username=? Parameters: [admin]
    	at org.apache.commons.dbutils.QueryRunner.rethrow(QueryRunner.java:542)
    	at org.apache.commons.dbutils.QueryRunner.query(QueryRunner.java:399)
    	at com.atguigu.dao.impl.BaseDao.queryForOne(BaseDao.java:49)
    	at com.atguigu.dao.impl.UserDaoImpl.queryUserByUsername(UserDaoImpl.java:11)
    	at com.atguigu.test.UserDaoTest.queryUserByUsername(UserDaoTest.java:14)
    	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    	at java.lang.reflect.Method.invoke(Method.java:498)
    	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
    	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
    	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

### 解决方法： ###

将 `sql` 语句中的 `'` 改为 \`，如：

修改前:
    select 'id','username','password','email' from t_user where username=?;
    
    修改后：
    select `id`,`username`,`password`,`email` from t_user where username=?;

### 程序运行： ###

十二月 26, 2020 8:07:43 上午 com.alibaba.druid.pool.DruidDataSource info
    信息: { dataSource-1} inited
    User{ id=1, username='admin', password='admin', email='admin@163.com'}
    
    Process finished with exit code 0

问题解决，完美！