巧妙mybatis避免Where 空条件的尴尬

<select id="findactivebloglike" resulttype="blog">
 select * from blog
 where
 <if test="state != null">
 state = #{state}
 </if> 
</select>

<select id="findactivebloglike" resulttype="blog">
 select * from blog
 where 1=1
 <if test="state != null">
 and state = #{state}
 </if> 
</select>

<select id="findactivebloglike" resulttype="blog">
 select * from blog
 <where>
  <if test="state != null">
   and state = #{state}
  </if>
 </where> 
</select>

@selectprovider(type=deptdynasqlprovider.class,method="count")
 integer count(map<string, object> params);
//deptdynasqlprovider.class 类中的方法
public string count(map<string, object> params){
return new sql(){{select("count(*)");from(depttable);if(params.get("dept") != null){dept dept = (dept) params.get("dept");if(dept.getname() != null && !dept.getname().equals("")){where(" name like concat ('%',#{dept.name},'%') ");}}}}.tostring();}

@select({"<script>",
 "select * from tbl_order",
 "where 1=1",
 "<when test='title!=null'>",
 "and mydate = #{mydate}",
 "</when>",
 "</script>"})