How can i pass just string to parameter in mybatis collection column?

Question

I have make sql query by MyBatis and MariaDB in Spring.

This is my failed MyBatis codes.

<resultMap type="Member" id="memberMap">
    <result property="uid" column="uid" />
    <result property="id" column="id" />
    <result property="name" column="name" />
    <collection property="privacyList" column="{ mid = uid, type = 'phone'}" ofType="MemPhone" select="getPrivacyList" />
</resultMap>

<resultMap type="MemPrivacy" id="memPrivacyMap">
    <result property="uid" column="uid" />
    <result property="mid" column="mid" />
    <result property="type" column="type" />
    <result property="name" column="name" />
    <result property="content" column="content" />
    <result property="sort" column="sort" />
</resultMap>

<select id="getMemberList" resultMap="memberMap">
    select * from `member`
</select>

<select id="getPrivacyList" resultMap="memPrivacyMap" parameterType="map">
    select *
    from `mem_privacy`
    where `mid` = #{ mid } and `type` = #{ type }
</select>

Because column have to be defined as a column, not a string in line 4.

So, i changed this as followed code.

select *, 'phone' as `type_phone`
from `mem_privacy`
where `mid` = #{ mid } and `type` = #{ type }

<collection property="privacyList" column="{ mid = uid, type = type_phone }" ofType="MemPhone" select="getPrivacyList" />

Select string value as column and use it to collection column.

Changed codes was ran well.

But, i like to use just string in there.

How can i this?

Somebody help me~~

Answer 1

in your resultMap with the name memberMap , you tell myBatis, to 'build' the collection for Member#privacyList via the select referred by select="getPrivacyList"

the column -property, passes the content of the declared columns as parameters into the referred select.

in your case ( column="{ mid = uid, type = type_phone }" ) content of column uid as parameter named mid and content of column type_phone as parameter type. the corresponding contents are available as #{mid} / ${mid} and #{type} / ${type} in your 'sub-query'.

if you want to pass a specified String into the select-statement, you have to add a column to your getMemberList -select-statement

SELECT member.*, 'phone' AS desired_type FROM MEMBER

now you can pass this columns content, that is a String, into your sub-query via `column="{ mid = uid, desired_type = desired_type}".

i suggest to not use sql or database key-words, as type , for column-names