关于mybatis的使用之如何传递参数总结（一）

?<第一个例子>

修改删除这些没有返回值的操作，我们可以这样套用

1，action得到前台传过来的参数，service如何使用参数。

public void modifyUserRole(int userId, int roleId) {Map<String, Object> paramMap = new HashMap<String, Object>();paramMap.put("userId", userId);paramMap.put("roleId", roleId);userRoleMapper.modifyUserRole(paramMap);}

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2，mapper.java和mapper.xml

public void  modifyUserRole(Map<String, Object> map);

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<update id="modifyUserRole"  parameterType="java.util.HashMap"> update  TS_USER_ROLE t set t.role_id=#{roleId} where t.user_id=#{userId}</update>

结语：这样就完了，就这么简单。

<第二个例子>

如果有返回值的，我们可以这样套用

1，action直接把前台传过来的参数去调用service

userRoleBean=this.userService.getUserRoleById(user.getId());

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2，接着传，这是service里面

public UserRoleBean getUserRoleById(int userId) {return this.userRoleMapper.getUserRoleById(userId);}

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3，mapper.java和mapper.xml

public UserRoleBean getUserRoleById(int userId);

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<select id="getUserRoleById" resultMap="userRoleResultMap"  parameterType="int"> select * from TS_USER_ROLE    where user_id=#{userId}</select>

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结语：接口的方法是用对象声明，mapper.mxl里面的resultMap也是这样返回。

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<第三个例子>

如果此表里面的字段的外键是关联表的主键，那么，怎么相关联表的查询

1，bean里面这样写

private int id; // idprivate String name;// 姓名private String userName;// 用户名private String password;// 密码private int unitId;// 单位编码private int deptId;// 单位编码private int userType;// 用户类型private int state;// 用户状态private Dept dept;// 部门// deptId是外键，链接Dept表.// 还是把所有字段声明完整，然后再添加一个成员变量

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2，,mapper.xml配置文件这样

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<resultMap id="userResultMap" type="com.zjedusoft.gdqs.bean.User"><id property="id" column="id" /><result property="name" column="NAME" /><result property="userName" column="USER_NAME" /><result property="password" column="PASSWORD" /><result property="unitId" column="UNIT_ID" /><result property="userType" column="USER_TYPE" /><result property="state" column="STATE" /><result property="deptId" column="DEPT_ID"/><result property="using" column="using"/><association property="dept" column="DEPT_ID" javaType="com.zjedusoft.gdqs.bean.Dept" resultMap="deptResultMap"/>

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然后使用是这样，这里多了其他的角色和权限，不管了，先贴上来吧。

<select id="getAllUserByPage" resultMap="userResultMap" parameterType="java.util.HashMap"> select zong.* from  (  select temp.*,rownum rownum_  from(               select u.*,r.role_name as role_name,d.id as did,d.dept_name as dept_name                from ts_user_info u left join ts_user_role ur on u.id =ur.user_id                      left join ts_role r       on ur.role_id=r.id                      left join ts_dept d       on    u.dept_id=d.id <where> <if test="keyword != '%null%'"> and u.USER_NAME   like #{keyword} </if>   <if test="keyword != '%null%'"> or u.NAME   like #{keyword} </if>   <if test="keyword != '%null%'"> or d.dept_name   like #{keyword} </if>  </where> order by u.id                                                ) temp  where rownum <= #{maxResult}                     )  zong                   where zong.rownum_ > #{skipResult}                           </select>

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3，再看action,service，mapper都和其他一样

public List<User> getAllUserByPage(Map<String, Object> map);

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<第四个例子>

那多对多，一对多怎么办呢。下面看。

1，还是bean里面

//多表查询，要把需要查询的collection当做属性get/setprivate UserRoleBean userRoleBean;private RoleBean   roleBean;private RolePopedomBean rolePopedomBean;private PopedomBean popedomBean;private boolean using;// 是否被使用中

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2.mapper.xml里面的

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<collection property="userRoleBean" ofType="com.zjedusoft.gdqs.bean.UserRoleBean"><id property="id" column="id" /><result property="userId" column="USER_ID" /><result property="roleId" column="ROLE_ID" /></collection><collection property="roleBean" ofType="com.zjedusoft.gdqs.bean.RoleBean"><id property="id" column="id" /><result property="roleName" column="ROLE_NAME" /><result property="roleComments" column="ROLE_COMMENTS" /><result property="state" column="STATE" /></collection><collection property="rolePopedomBean" ofType="com.zjedusoft.gdqs.bean.RolePopedomBean"><id property="id" column="id" /><result property="roleId" column="ROLE_ID" /><result property="popedomId" column="POPEDOM_ID" /></collection><collection property="popedomBean" ofType="com.zjedusoft.gdqs.bean.PopedomBean"><id property="id" column="id" /><result property="LevleCode" column="LEVEL_CODE" /><result property="ParentId" column="PARENT_ID" /><result property="PopedomName" column="POPEDOM_NAME" /><result property="Url" column="URL" /><result property="PopedomComments" column="POPEDOM_COMMENTS" /><result property="type" column="TYPE" /><result property="state" column="STATE" /></collection></resultMap>

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然后还是这样，呵呵。

<select id="getAllUserByPage" resultMap="userResultMap" parameterType="java.util.HashMap"> select zong.* from  (  select temp.*,rownum rownum_  from(               select u.*,r.role_name as role_name,d.id as did,d.dept_name as dept_name                from ts_user_info u left join ts_user_role ur on u.id =ur.user_id                      left join ts_role r       on ur.role_id=r.id                      left join ts_dept d       on    u.dept_id=d.id <where> <if test="keyword != '%null%'"> and u.USER_NAME   like #{keyword} </if>   <if test="keyword != '%null%'"> or u.NAME   like #{keyword} </if>   <if test="keyword != '%null%'"> or d.dept_name   like #{keyword} </if>  </where> order by u.id                                                ) temp  where rownum <= #{maxResult}                     )  zong                   where zong.rownum_ > #{skipResult}                           </select>

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