Adding a Column to a Many-to-Many Table Using Liferay

I would like to add a column to the association table using a builder service on liferay!

<entity name="entity1" local-service="true" remote-service="false">

    <column name="entity1Id" type="long" primary="true" id-type="sequence"

        id-param="id_entity1_sequence"></column>

    <column name="name" type="String"></column>

    <column name="entity2s" type="Collection" mapping-table="entity1_entity2"
        entity="entity2"></column>

        <finder name="Name" return-type="entity1" unique="true">
        <finder-column name="name"></finder-column>

    </finder>

</entity>

<entity name="entity2" local-service="true" remote-service="false">

    <column name="entity2Id" type="long" primary="true" id-type="sequence"

        id-param="id_entity2_sequence"></column>

    <column name="header" type="String"></column>

    <column name="value" type="String"></column>

    <column name="entity1s" type="Collection" mapping-table="entity1_entity2"
        entity="entity1"></column>


</entity>

      

        
        
        
      

    

I mean i need to add a column to entity1_entity2 table

Do you have any suggestions?