<select id="selectProject" parameterType="project" resultMap="BaseResultMap"> select * from project <where> <if test="pName != null and pName != ''"> and p_name like concat('%', #{pName}, '%')</if> <if test="pManager != null and pManager != ''"> and p_manager = #{pManager}</if> <if test="pPeople != null and pPeople != ''"> and p_people = #{pPeople}</if> <if test="pImg != null and pImg != ''"> and p_img = #{pImg}</if> <if test="pDescribe != null and pDescribe != ''"> and p_describe = #{pDescribe}</if> <if test="pTasks != null "> and p_tasks = #{pTasks}</if> <if test="pTasksplan != null "> and p_tasksplan = #{pTasksplan}</if> <if test="pTasksre != null">and p_tasksre = #{pTasksre}</if> <if test="pPlanprogress != null "> and p_planprogress = #{pPlanprogress}</if> <if test="pProgress != null "> and p_progress = #{pProgress}</if> <if test="pStatus != null "> and p_status = #{pStatus}</if> </where> </select>
时间: 2024-03-07 20:51:42 浏览: 79
根据您提供的代码,您的查询语句看起来没有问题。但是,我注意到您在查询语句中使用了 parameterType="project",这意味着您的查询方法应该接受一个 Project 对象作为参数。由于您的查询结果为 null,有可能是传递给查询方法的 Project 对象中的属性值不正确导致查询失败。您可以检查一下传递给 selectProject 方法的 Project 对象是否正确设置了属性值。如果您能提供更多的代码和错误信息,我可以更准确地帮助您解决问题。
相关问题
<select id="selectSysRpuserListByToday" parameterType="SysRpuser" resultMap="SysRpuserResult"> <include refid="selectSysRpuserVo"/> <where> <if test="tid != null and tid != ''"> and tid = #{tid}</if> <if test="tusername != null and tusername != ''"> and tusername like concat('%', #{tusername}, '%')</if> <if test="tnickname != null and tnickname != ''"> and tnickname like concat('%', #{tnickname}, '%')</if> <if test="uamount != null and uamount != ''"> and uamount = #{uamount}</if> <if test="ustatus != null and ustatus != ''"> and ustatus = #{ustatus}</if> <if test="forgroup != null and forgroup != ''"> and forgroup = #{forgroup}</if> <if test="createtime != null "> and createtime = #{createtime}</if> <if test="agentTid != null and agentTid != ''"> and agentTid = #{agentTid}</if> </where> </select>优化以上代码,要求能查询当日数据
可以在 `<where>` 标签中添加对 `createtime` 字段的判断,使查询仅返回当日的数据。具体代码如下:
```xml
<select id="selectSysRpuserListByToday" parameterType="SysRpuser" resultMap="SysRpuserResult">
<include refid="selectSysRpuserVo"/>
<where>
<if test="tid != null and tid != ''"> and tid = #{tid}</if>
<if test="tusername != null and tusername != ''"> and tusername like concat('%', #{tusername}, '%')</if>
<if test="tnickname != null and tnickname != ''"> and tnickname like concat('%', #{tnickname}, '%')</if>
<if test="uamount != null and uamount != ''"> and uamount = #{uamount}</if>
<if test="ustatus != null and ustatus != ''"> and ustatus = #{ustatus}</if>
<if test="forgroup != null and forgroup != ''"> and forgroup = #{forgroup}</if>
<!-- 添加当日数据判断 -->
<if test="createtime != null">
and createtime >= #{createtime}
and createtime <= DATE_ADD(#{createtime}, INTERVAL 1 DAY)
</if>
<if test="agentTid != null and agentTid != ''"> and agentTid = #{agentTid}</if>
</where>
</select>
```
这个代码中,`DATE_ADD(#{createtime}, INTERVAL 1 DAY)` 表示将 `#{createtime}` 的日期加 1 天,相当于查询当日的数据。
在Java代码中,可以这样调用:
```java
SysRpuser obj = new SysRpuser();
obj.setCreatetime(new Date());
List<SysRpuserResult> result = sqlSession.selectList("selectSysRpuserListByToday", obj);
```
这样,就可以查询出当日的数据了。
为什么以下代码会导致上述错误 <select id="selectList" resultMap="BaseResultMap" parameterType="com.wego.entity.query.CartItemQuery"> select <include refid="Base_Column_List"/> from tb_cart_item <where> <if test="id != null"> and id = #{id} </if> <if test="goodsId != null"> and goodsId= #{goodsId} </if> <if test="amount != null"> and amount= #{amount} </if> <if test="money != null"> and money= #{money} </if> </where> order by update_time desc </select>
根据你提供的代码片段,错误可能出现在以下位置:
```xml
<if test="id != null">
and id = #{id}
</if>
```
```xml
<if test="goodsId != null">
and goodsId = #{goodsId}
</if>
```
```xml
<if test="amount != null">
and amount = #{amount}
</if>
```
```xml
<if test="money != null">
and money = #{money}
</if>
```
这些 `<if>` 标签用于根据条件动态生成 SQL 查询。然而,在生成的 SQL 查询中,如果这些条件都不满足(即对应的参数为 null),那么会导致生成的 SQL 查询中存在多余的 "and" 关键字,从而导致 SQL 语法错误。
为了解决这个问题,你可以在每个 `<if>` 标签的末尾添加一个空格,以确保在条件不满足时生成的 SQL 查询仍然是有效的。例如:
```xml
<if test="id != null">
and id = #{id}
</if>
```
改为:
```xml
<if test="id != null">
and id = #{id}
</if>
```
通过这样的修改,生成的 SQL 查询将不会存在多余的 "and" 关键字,从而避免了 SQL 语法错误。
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