<!-- 根據主鍵id查詢訂單信息-->
<select id="getExployeeByUserId" parametertype="java.lang.string" resulttype="com.my.vo.Exployee">
select
a.user_id as userId,
a.user_code as userCode,
a.user_name as userName,
a.status status,
a.finish_time as finishTime,
a.create_time as createTime
from
t_exployee a
where a.user_id = #{userId,jdbctype=varchar}
</select>
<select id="getExployeeByUserCode" parametertype="java.lang.string" resulttype="com.my.vo.Exployee">
select
a.user_id as userId,
a.user_code as userCode,
a.user_name as userName,
a.status status,
a.finish_time as finishTime,
a.create_time as createTime
from
t_exployee a
where a.user_code = #{userCode,jdbctype=varchar}
</select>
public class Exployee {
private static final long serialVersionUID = 1L;
private String userId;
private String userCode;
private String userName;
private String status;
private Date createTime;
private Date finishTime;
//自動生成set、get方法
｝
兩個查詢，參數和返回都是一樣的，getExployeeByUserId 百試不爽，必定查詢出結果；但是getExployeeByUserCode查詢，時不時的查詢結果返回爲null，明明是有數據的；愁死我了，你要是一直查不出來也行啊，一會有，一會沒有。百度的時候，有說是因爲數據庫表的字段和java的實體類字段對不上，建議配置ResultMap；查詢返回的時候，用resultMap="setExployee" 而不是resultType
<resultMap id="setExployee" type="com.my.vo.Exployee">
<result column="user_id" property="userId" jdbcType="VARCHAR"/>
<result column="user_code" property="userCode" jdbcType="VARCHAR"/>
<result column="user_name" property="userName" jdbcType="VARCHAR"/>
<result column="status" property="status" jdbcType="VARCHAR"/>
<result column="create_time" property="createTime" jdbcType="TIMESTAMP"/>
<result column="finish_time" property="finishTime" jdbcType="TIMESTAMP"/>
</resultMap>
數據庫表的字段和java的實體類字段對不上，這是原因之一，可以先覈實一下，排除一下是不是這個原因；我反正不是這個原因
我的情況是這樣的user_id 是主鍵，這個查詢百分百；但是user_code不是主鍵，在mybatis裏面，非主鍵查詢可能不會返回唯一值，所以返回結果不能用單實體，必須要用List類型接收，我後來把接口方法改成返回List，就能查詢出結果了。
也是繞了好久，各種排查