mybatis框架中动态SQL的编写

1.动态SQL：在SQL语句中加入流程控制。比如加入if，foreach等。

重点掌握if语句：

案例1：

<update id="updateItem" parameterType="com.gxa.bj.model.UserInfo">

update userinfo set

<if test="userName!=null">

userName = #{userName},

</if>

<if test="userPwd!=null">

userPwd = #{userPwd},

</if>

<if test= "userEmail!=null">

userEmail = #{userEmail},

</if>

<if test= "userAddress!=null">

userAddress = #{userAddress},

</if>

<if test= "regReason!=null">

regReason = #{regReason},

</if>

userId=#{userId} Where userId=#{userId}

</update>

案例2：

<select id="getList" parameterType="com.gxa.bj.model.UserInfo" resultType="com.gxa.bj.model.UserInfo">

Select * From userInfo Where 1=1

<if test="userName!=null">

And userName like #{userName}

</if>

<if test="userId>0">

And userId =#{userId}

</if>

<if test="userPwd!=null And userPwd!=''">

And userPwd like #{userPwd}

</if>

</select>