while defining resultmap in ibatis, provides option set javatype , jdbctype each property column mapping. e.g. <resultmap id="employee" class="com.mycompany.employee"> <result property="firstname" column="first_name" javatype="?" jdbctype="?"/> </resultmap> wanted know when should defining javatype , jdbctype ? have seen mapping just works without defining these properties , in others have define them. edit: see selected answer below above question. also, have exhaustive list out of javatype , jdbctype should defined? edit: javatype should 1 of well-known types e.g. java.lang.string , java.util.date , jdbctype should coming out of java.sql.types thanks in advance! for jdbctype documentation (for ibatis 3) states: the jdbc type required nullable columns upon insert, update or delete. on page 33 in document list of supported jdbc types. for javatype attrib...