如何使用ibatis将类型为java.util.Set的数据插入到我的sql数据库中？

Question

How to insert data of type java.util.Set into mysql db column of type set(mysql set type) ?

My POJO :

public class UserTEO 
{
    private Integer id;
    private Set changedfieldset;
    //getters and setters
}

xml file :

<sqlMap namespace="user"> 

    <typeAlias alias="USER" type="com.howtodoinjava.ibatis.demo.dto.UserTEO" />
    <insert id="addUser" parameterClass="USER">
        INSERT INTO USERINFO (ID,CHANGEDFIELDSET)
         VALUES(#id#,#changedfieldset#);
    </insert>
</sqlMap>

database :

CREATE TABLE USERINFO
(
    ID INT,
    CHANGEDFIELDSET SET('')
);

Exception :

com.ibatis.common.jdbc.exception.NestedSQLException:   
--- The error occurred in user.xml.  
--- The error occurred while applying a parameter map.  
--- Check the user.addUser-InlineParameterMap.  
--- Check the parameter mapping for the 'changedfieldset' property. 

Please help. Thanks !

Answer 1

I guess you explicitly want to work with (old) ibatis and not Mybatis. So here is the documentation I referenced to.

The Mysql SET expects a string of set values separated by commas and without white spaces: StringUtils.join(set, ",") . So you have to use a type handler to transform the java Set into this string: Extend BaseTypeHandler , speceially overriding setParameter method.

Then call as follows:

INSERT INTO USERINFO (ID,CHANGEDFIELDSET)
         VALUES(#id#,#changedfieldset,handler=YourCustomTypeHandlerTypeAlias#)