title: Add default value when field is null with MyBatis
body: <p>I want to insert the default value from database when my field is null. I use an Oracle Database.</p>
  
  <pre><code>CREATE TABLE "EMPLOYEE" 
     ("COL1" VARCHAR2(800) NOT NULL ENABLE, 
      "COL2" VARCHAR2(100) DEFAULT NOT NULL 'toto', 
      CONSTRAINT "PK_EMPLOYEE" PRIMARY KEY ("COL1")
  </code></pre>
  
  <p>with a simple SQL request, we can write:</p>
  
  <pre><code>insert into EMPLOYEE(COL1,COL2) values ('titi', default)
  </code></pre>
  
  <p>How can i do this with annotations MyBatis in Spring? I must create an HandlerType?</p>