如何在插入时使用typeHandler映射mybatis中的枚举类型

Question

我已经使用enum有一段时间了，但它不会按我的方式进行。有没有人能给我点提示？我正在尝试在MySql中使用Enum类型，并且在我的代码中也使用了Enum类。

正如现在的代码，它将插入星期一，但它也将尝试在workdayID上插入星期一……我不明白workdayID的意思。我相信我必须以某种方式处理DAY_TYPE。也许定义一个typeHandler？？但是我试过了，它不会工作，或者是因为我不能做正确的？

我也尝试了org.apache.ibatis.type.EnumTypeHandler，但没有成功，如下所示

    #{DAY_TYPE,typeHandler=org.apache.ibatis.type.EnumTypeHandler}

DAY_TYPE.java

    package tut.model;
    import java.io.Serializable;
    public enum DAY_TYPE implements Serializable{
        MONDAY(1),TUESDAY(2),WEDNESDAY(3),THURSDAY(4),FRIDAY(5),SATURDAY(6),SUNDAY(7);
        private int id; private int workdayID;

        private DAY_TYPE(int id) { this.id = id; }

        public int getId() { return id;    }
        public void setId(int id) {  this.id = id;    }

        public int getWorkdayID() { return workdayID;    }
        public void setWorkdayID(int workdayID) {this.workdayID = workdayID;}
    }

DAY_TYPE_Mapper.xml

    <insert id="insert" parameterType="DAY_TYPE" useGeneratedKeys="true" keyProperty="iddaytaype">
        INSERT INTO daytaype (DAY_TYPE, workdayID)
        VALUES (#{DAY_TYPE},#{workdayID})
        <selectKey keyProperty="iddaytaype" resultType="long" order="AFTER">
            SELECT LAST_INSERT_ID();
        </selectKey>
    </insert>

<!-- <insert id="insert" parameterMap="insert-params" useGeneratedKeys="true" keyProperty="iddaytaype"> -->
    <parameterMap id="insert-params"   type="DAY_TYPE">
        <parameter property="DAY_TYPE" javaType="DAY_TYPE" typeHandler="mappings.XenumTypeHandler"  />
        <parameter property="workdayID" javaType="int" />
    </parameterMap>  

我的数据库表

    CREATE TABLE `daytaype` (
      `iddaytaype` int(11) NOT NULL AUTO_INCREMENT,
      `DAY_TYPE` enum('MONDAY','TUESDAY','WEDNESDAY','THURSDAY','FRIDAY','SATURDAY','SUNDAY') NOT NULL,
      `workdayID` int(11) unsigned DEFAULT NULL,
      PRIMARY KEY (`iddaytaype`),
      KEY `fk_workDayID_idWorkDay` (`workdayID`)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8;=InnoDB DEFAULT CHARSET=utf8;      

Answer 1

Workday是这样存在的

    public class Workday implements Serializable{
        private long idWorkDay;
        private Date start;
        private Date end;
        private List<Workbreak> workBreaks;
        private DAY_TYPE DAY_TYPE;
        private long workweekID;
        getter setter....

当然，正确的解决方案是在workday表中添加枚举...而且我相信它会减少数据库的占用。

    <insert id="insert" parameterType="workday" useGeneratedKeys="true" keyProperty="idWorkDay">
      INSERT INTO workday 
        ( start , end , workweekID , DAY_TYPE )
      VALUES (
        #{start},
        #{end},
        #{workweekID},
        #{DAY_TYPE, typeHandler=org.apache.ibatis.type.EnumTypeHandler}
      )
        <selectKey keyProperty="idWorkDay" resultType="long" order="AFTER">
            SELECT LAST_INSERT_ID();
        </selectKey>
    </insert>   

现在删除daytaype表，并直接在workday表中添加枚举。

    CREATE TABLE `workday` (
      `idworkday` int(11) NOT NULL AUTO_INCREMENT,
      `start` time DEFAULT '08:00:00',
      `end` time DEFAULT '17:00:00',
      `workweekID` int(11) DEFAULT NULL,
      `DAY_TYPE` enum('MONDAY','TUESDAY','WEDNESDAY','THURSDAY','FRIDAY','SATURDAY','SUNDAY') DEFAULT NULL,
      PRIMARY KEY (`idworkday`),
      KEY `fk_workweek_workweekID` (`workweekID`),
      CONSTRAINT `fk_workweek_workweekID` FOREIGN KEY (`workweekID`) REFERENCES `workweek` (`idworkweek`) ON DELETE CASCADE ON UPDATE NO ACTION
    ) ENGINE=InnoDB AUTO_INCREMENT=139 DEFAULT CHARSET=utf8 ;

Answer 2

重写getter setter。我是这样的：

@Column(name = "type")
private MailType type;

public String getType(){
    return type.name();
}
public void setType(String type){
    this.type = MailType.valueOf(type);
}
public MailType getTypeEnum(){
    return type;
}
public void setTypeEnum(MailType type){
    this.type = type;
}

Answer 3

在本例中，DAY_TYPE包含一个成员id。现在，如果您将ENUM作为id存储在数据库中，那么即使您没有将Enum与数据库同步，也可以使用CustomEnumTypeHandler为您处理DAY_TYPE。