mybatis怎么写sql语句

发布网友发布时间：2022-04-08 05:48

共2个回答

懂视网时间：2022-04-08 10:09

User findUser(String usernumber) { return (User) sqlSessionTemplate.selectOne("findUserByUsernumber", usernumber); }

xml代码

//对应paramterType="string"
<select id="findUserByUsernumber" parameterType="string" resultType="User">
  select * from user where usernumber = #{usernumber}
 </select>

2.Java实体类型参数

java实体类型参数：将parameterType的值设为对应的 Java实体类，然后用#{类的属性名}来获取

java代码

//User实体类
public void updateUser(User user) {
 sqlSessionTemplate.update("updateUser", user); 
 }

xml代码

//将parameterType类型指向对应的类的具体地址（包名+类名），也可指向typeAlias中的别名（在mybatis.xml）文件中
<update id="updateUser" parameterType="User" >
  update user set username=#{username},loginname=#{loginname},loginpassword=#{loginpassword},sex=#{sex},birthday=#{birthday} where usernumber=#{usernumber}
 </update>

3.多个基本类型参数
在具体业务关系中，往往需要传多个参数，比如：登录----->用户名+密码

public User findUser(String loginname, String loginpassword) {
 // TODO Auto-generated method stub
 Map<String,String> map=new HashMap<String, String>();
 map.put("loginname", loginname);
 map.put("loginpassword", loginpassword);
 return (User) sqlSessionTemplate.selectOne("loginUser", map);
 
 }

 <select id="loginUser" parameterType="map" resultType="User">
  select * from user where loginname=#{loginname} and loginpassword=#{loginpassword}
 </select>

利用map知识多参数传递的一种方式，还有其他方式可以实现

MyBatis的SQL语句映射文件详解（三）----参数传递

标签：

热心网友时间：2022-04-08 07:17

mybatis的sql和你在数据库客户端执行的sql是一样的，但是在mybatis中调用的sql一般都是动态的，所以用到了参数传递。这个mybatis有对应的标签以及相应的变量来实现。你可以搜索下mybatis标签。同时给你一个参考的你看看，这个是一个查询用户的

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<select id="queryUsers" parameterType="map" resultType="xx.xx.xx.bean.UserBean">
<![CDATA[
select
ID,
LOGIN_NAME AS loginName,
PASSWORD,
REAL_NAME AS realName,
POSITION,
(SELECT D.POSITION_NAME FROM UNIT_POSITION D WHERE D.POSITION_CODE=T.POSITION) POSITIONNAME,
USER_TYPE AS userType,
SEX,
PID,
TO_CHAR(T.BIRTHDAY,'YYYY-MM-DD') BIRTHDAY,
EMAIL,
CONTACT_TEL AS contactTel,
CONTACT_MOBILE AS contactMobile,
CONTACT_FAX AS contactFax,
CONTACT_ZIP AS contactZip,
CONTACT_ADDR AS contactAddr,
STATUS,
EDUCATION,
(SELECT D.EDUCATION_NAME FROM UNIT_EDUCATION D WHERE D.EDUCATION_CODE=T.EDUCATION AND D.STATUS=0) EDUCATIONNAME,
NATION,
POLITICAL,
REMARK,
TO_CHAR(T.CREATE_DATE,'YYYY-MM-DD HH24:MI:SS') createDate,
(SELECT D.REAL_NAME FROM UNIT_USER D WHERE D.ID= T.CREATE_USER_ID) createUserId,
TO_CHAR(T.UPDATE_DATE,'YYYY-MM-DD HH24:MI:SS') updateDate,
(SELECT D.REAL_NAME FROM UNIT_USER D WHERE D.ID= T.UPDATE_USER_ID) updateUserId
from UNIT_USER T
]]>
<where>
T.STATUS='1'
<if test="realName !=null and realName !=''">
and T.REAL_NAME like '%${realName}%'
</if>
<if test="nexusDpartment !=null">
AND T.ID IN (SELECT DISTINCT D.USER_ID FROM UNIT_USER_DEPT D WHERE D.DEPT_CODE IN (${nexusDpartment}))
</if>
<if test="deptCode !=null and deptCode !=''">
AND T.ID IN (SELECT DISTINCT D.USER_ID FROM UNIT_USER_DEPT D WHERE D.DEPT_CODE = #{deptCode})
</if>
</where>
<if test="sort != null and sort != ''">
order by ${sort}
<if test="direction != null and direction != ''">
${direction}
</if>
</if>
</select>