It's a mistake to make a simple change today.
If the transmission mode is not correct, there is usually a problem with the transmission parameters, and there is a mapper writing error. But the author is using the auto generation tool, so did not look carefully, resulting in mapper error.
This is the correct code

    <update id="updateSelective" parameterType="com.hxzy.entity.Member">
        update member
        <set>
            <if test="email != null">
                email = #{email,jdbcType=VARCHAR},
            </if>
            <if test="credit != null">
                credit = #{credit,jdbcType=INTEGER},
            </if>
            <if test="gold != null">
                gold = #{gold,jdbcType=DOUBLE},
            </if>
            <if test="realname != null">
                realname = #{realname,jdbcType=VARCHAR},
            </if>
            <if test="mobile != null">
                mobile = #{mobile,jdbcType=VARCHAR},
            </if>
            <if test="pwd != null">
                pwd = #{pwd,jdbcType=VARCHAR},
            </if>
            <if test="createtime != null">
            createtime =#{createtime，jdbcType=INTEGER},
            </if>
            <if test="istemplate != null">
                istemplate = #{istemplate,jdbcType=INTEGER},
            </if>
            <if test="status != null">
                `status` = #{status,jdbcType=INTEGER},
            </if>
            <if test="experience != null">
                experience = #{experience,jdbcType=INTEGER},
            </if>
            <if test="avatar != null">
                avatar = #{avatar,jdbcType=VARCHAR},
            </if>
            <if test="outgold != null">
                outgold = #{outgold,jdbcType=DOUBLE},
            </if>
            <if test="outgoldinfo != null">
                outgoldinfo = #{outgoldinfo,jdbcType=VARCHAR},
            </if>
            <if test="weixinOpenid != null">
                weixin_openid = #{weixinOpenid,jdbcType=VARCHAR},
            </if>
            <if test="alipayOpenid != null">
                alipay_openid = #{alipayOpenid,jdbcType=VARCHAR},
            </if>
        </set>
        where openid = #{openid,jdbcType=VARCHAR}
    </update>

This is the wrong code

    <update id="updateSelective" parameterType="com.hxzy.entity.Member">
        update member
        <set>
            <if test="email != null">
                email = #{email,jdbcType=VARCHAR},
            </if>
            <if test="credit != null">
                credit = #{credit,jdbcType=INTEGER},
            </if>
            <if test="gold != null">
                gold = #{gold,jdbcType=DOUBLE},
            </if>
            <if test="realname != null">
                realname = #{realname,jdbcType=VARCHAR},
            </if>
            <if test="mobile != null">
                mobile = #{mobile,jdbcType=VARCHAR},
            </if>
            <if test="pwd != null">
                pwd = #{pwd,jdbcType=VARCHAR},
            </if>
       
            createtime =#{createtime，jdbcType=INTEGER},

            <if test="istemplate != null">
                istemplate = #{istemplate,jdbcType=INTEGER},
            </if>
            <if test="status != null">
                `status` = #{status,jdbcType=INTEGER},
            </if>
            <if test="experience != null">
                experience = #{experience,jdbcType=INTEGER},
            </if>
            <if test="avatar != null">
                avatar = #{avatar,jdbcType=VARCHAR},
            </if>
            <if test="outgold != null">
                outgold = #{outgold,jdbcType=DOUBLE},
            </if>
            <if test="outgoldinfo != null">
                outgoldinfo = #{outgoldinfo,jdbcType=VARCHAR},
            </if>
            <if test="weixinOpenid != null">
                weixin_openid = #{weixinOpenid,jdbcType=VARCHAR},
            </if>
            <if test="alipayOpenid != null">
                alipay_openid = #{alipayOpenid,jdbcType=VARCHAR},
            </if>
        </set>
        where openid = #{openid,jdbcType=VARCHAR}
    </update>

Yes, the code generation tool did not determine if createtime is null, resulting in an error.