java.sql.SQLException: Cannot set createTime: incompatible types

今日在写OrderDaoImpl类，进行测试一直报错，起初以为是Order类的名字与数据库不同引起，在查询函数中起了别名来解决，但一直报Cannot set createTime错误，上网找了说法，都说是名字要对上，偶然间看到一篇sql错误记录中有一样的错误，照着改可以运行出结果。
sql错误记录错误链接

未改变之前的Order类

public class Order {
    private String orderId;
    private Date createTime;
    private BigDecimal totalMoney;
    // 0 未发货，1 已发货，2 表示已签收
    private Integer status;
    private Integer userId;

    public Order() {
    }
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t_order数据库：

OrderDaoImpl类

    public List<Order> queryOrders() {
        String sql = "select `order_id` orderId,`create_time` createTime,`total_money` totalMoney,`status`,`user_id` userId from t_order";
        return queryForList(Order.class,sql);
    }
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八月 08, 2022 10:16:33 下午 com.alibaba.druid.support.logging.JakartaCommonsLoggingImpl info
信息: {dataSource-1} inited
java.sql.SQLException: Cannot set createTime: incompatible types. Query: select `order_id` orderId,`create_time` createTime,`total_money` totalMoney,`status`,`user_id` userId from t_order Parameters: []
	at org.apache.commons.dbutils.QueryRunner.rethrow(QueryRunner.java:542)
	at org.apache.commons.dbutils.QueryRunner.query(QueryRunner.java:399)
	at com.study.dao.Impl.BaseDao.queryForList(BaseDao.java:71)
	at com.study.dao.Impl.OrderDaoImpl.queryOrders(OrderDaoImpl.java:24)
	at com.study.test.OrderDaoImplTest.queryOrders(OrderDaoImplTest.java:26)
	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$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)

java.lang.NullPointerException
	at com.study.test.OrderDaoImplTest.queryOrders(OrderDaoImplTest.java:27)
	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$2.evaluate(ParentRunner.java:268)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38)
	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)

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修改后的Order类，其中导入包为import java.sql.Timestamp;

public class Order {
    private String orderId;
    private Timestamp createTime;
    private BigDecimal totalMoney;
    // 0 未发货，1 已发货，2 表示已签收
    private Integer status;
    private Integer userId;

    public Order() {
    }
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解决方法：可以看到create_time在数据库中是datetime类型，在Order类中是Date()类型，结果报错，将Order类中createTime类型由Data改为Timestamp就可以了。

小结：

1. 查询中表中字段名要与bean类中的对应字段命名相同，不然就需要在查询语句中用别名。
2. 查询中表中字段类型要与bean类中的对应字段命名类型相对应
3. 在bean类中要创建一个无参构造器
   1对应Cannot set createTime: incompatible types
   2和3 对应该错误：java.sql.SQLException:Cannot create

> 数据库字段类型                  bean字段类型
> int                             int
> varchar	 					 String
> datetime						 timestamp
> 
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