本文要實現Mybatis多引數查詢與列表查詢不同方式實現，以一個例項來說明。

一、查詢所有資料，返回List

查詢出列表，也就是返回list, 在我們這個例子中也就是 List<Employeer> , 這種方式返回資料，需要在Employeer.xml 裡面配置返回的型別 resultMap, 注意不是 resultType, 而這個resultMap 所對應的應該是我們自己配置的

[html] view plain copy print?

1. <!-- 定義資料庫欄位與實體物件的對映關係 -->  
2. <resultMap type="Employeer"
    id="resultMap">  
3.    <id property="employeer_id" column="employeer_id"/>   
4.    <result property="employeer_name" column="employeer_name"/>  
5.    <result property="employeer_age" column="employeer_age"/>  
6.    <result property="employeer_department" column="employeer_department"/>  
7.    <result property="employeer_worktype" column="employeer_worktype"/>  
8. </resultMap>  

 <!-- 定義資料庫欄位與實體物件的對映關係 -->
 <resultMap type="Employeer" id="resultMap">
    <id property="employeer_id" column="employeer_id"/> 
    <result property="employeer_name" column="employeer_name"/>
    <result property="employeer_age" column="employeer_age"/>
    <result property="employeer_department" column="employeer_department"/>
    <result property="employeer_worktype" column="employeer_worktype"/>
 </resultMap>
 

id、result是最簡單的對映，id為主鍵對映；result其他基本資料庫表字段到實體類屬性的對映。

查詢列表的語句在 Employeer.xml 中

[html] view plain copy print?

1. <!-- 返回list 的select 語句，注意 resultMap 的值是指向前面定義好的 -->  
2.     <select id="findEmployeerByName" parameterType="string" resultMap="resultMap">  
3.         select * from `t_employeer` where employeer_name like #{employeer_name}  
4.     </select>  

<!-- 返回list 的select 語句，注意 resultMap 的值是指向前面定義好的 -->
    <select id="findEmployeerByName" parameterType="string" resultMap="resultMap">
        select * from `t_employeer` where employeer_name like #{employeer_name}
    </select>

在EmployeerMapper 介面中增加方法：public List<Employeer> findEmployeerByName(String employeer_name);  
[java] view plain copy print?

1. /** 
2.  * 注意要和Employeer.xml的方法名對應 
3.  */  
4. public List<Employeer> findEmployeerByName(String employeer_name);     

	/**
	 * 注意要和Employeer.xml的方法名對應
	 */
	public List<Employeer> findEmployeerByName(String employeer_name);   

測試： [java] view plain copy print?

1. /** 
2.  * 查詢列表 
3.  */  
4. public static List<Employeer> getEmployeerList(String employeer_name){  
5.     SqlSession session = null;  
6.      List<Employeer> employeers=null;  
7.     try {  
8.         session = sqlSessionFactory.openSession();   
9.         EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);  
10.          employeers = employeerMapper.findEmployeerByName(employeer_name);    
11.            session.commit() ;         
12.     } finally {  
13.         session.close();  
14.     }  
15.     return employeers;  
16.    }  
17. public static void main(String[] args) {                              
18.     List<Employeer> employeers=getEmployeerList("張三");  
19.      for(Employeer employeer:employeers){  
20.             System.out.println(employeer);  
21.         }  
22. }  

	/**
	 * 查詢列表
	 */
	public static List<Employeer> getEmployeerList(String employeer_name){
		SqlSession session = null;
		 List<Employeer> employeers=null;
		try {
			session = sqlSessionFactory.openSession(); 
			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
			 employeers = employeerMapper.findEmployeerByName(employeer_name);	
            session.commit() ;  		
		} finally {
			session.close();
		}
		return employeers;
   
    }
	public static void main(String[] args) {							
		List<Employeer> employeers=getEmployeerList("張三");
		 for(Employeer employeer:employeers){
             System.out.println(employeer);
         }

	}

結果：

其中的資料的之前插入的，現在要查詢張三的列表全部都列出來了。

二、多引數查詢

（1）方法一

EmployeerMapper中定義

[java] view plain copy print?

1. /** 
2.  * 多引數查詢，注意要和Employeer.xml的方法名對應 
3.  */  
4. public List<Employeer> findEmployeerByNameandDep(String employeer_name,String employeer_department);  

	/**
	 * 多引數查詢，注意要和Employeer.xml的方法名對應
	 */
	public List<Employeer> findEmployeerByNameandDep(String employeer_name,String employeer_department);

Employeer.xml中定義 [html] view plain copy print?

1. <!-- 定義資料庫欄位與實體物件的對映關係 -->  
2. <resultMap type="Employeer" id="resultMap">  
3.    <id property="employeer_id" column="employeer_id"/>   
4.    <result property="employeer_name" column="employeer_name"/>  
5.    <result property="employeer_age" column="employeer_age"/>  
6.    <result property="employeer_department" column="employeer_department"/>  
7.    <result property="employeer_worktype" column="employeer_worktype"/>  
8. </resultMap>  

 <!-- 定義資料庫欄位與實體物件的對映關係 -->
 <resultMap type="Employeer" id="resultMap">
    <id property="employeer_id" column="employeer_id"/> 
    <result property="employeer_name" column="employeer_name"/>
    <result property="employeer_age" column="employeer_age"/>
    <result property="employeer_department" column="employeer_department"/>
    <result property="employeer_worktype" column="employeer_worktype"/>
 </resultMap>

[java] view plain copy print?

1. <!--多引數 查詢 返回list 的select 語句，注意 resultMap 的值是指向前面定義好的 -->  
2.      <select id="findEmployeerByNameandDep"  resultMap="resultMap">  
3.      select* from `t_employeer` where employeer_name=#{0} and employeer_department=#{1}  
4.      </select>   

<!--多引數 查詢 返回list 的select 語句，注意 resultMap 的值是指向前面定義好的 -->
     <select id="findEmployeerByNameandDep"  resultMap="resultMap">
     select* from `t_employeer` where employeer_name=#{0} and employeer_department=#{1}
     </select> 

由於是多引數那麼就不能使用parameterType， 改用#｛index｝是第幾個就用第幾個的索引，索引從0開始

測試程式碼：

[java] view plain copy print?

1. /** 
2.  * 多引數查詢列表 
3.  */  
4. public static List<Employeer> getEmployeerList(String employeer_name,String employeer_department){  
5.     SqlSession session = null;  
6.      List<Employeer> employeers=null;  
7.     try {  
8.         session = sqlSessionFactory.openSession();   
9.         EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);  
10.          employeers = employeerMapper.findEmployeerByNameandDep(employeer_name, employeer_department);  
11.            session.commit() ;         
12.     } finally {  
13.         session.close();  
14.     }  
15.     return employeers;  
16.    }  

	/**
	 * 多引數查詢列表
	 */
	public static List<Employeer> getEmployeerList(String employeer_name,String employeer_department){
		SqlSession session = null;
		 List<Employeer> employeers=null;
		try {
			session = sqlSessionFactory.openSession(); 
			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
			 employeers = employeerMapper.findEmployeerByNameandDep(employeer_name, employeer_department);
            session.commit() ;  		
		} finally {
			session.close();
		}
		return employeers;
   
    }

[java] view plain copy print?

1. public static void main(String[] args) {     
2.      System.out.println("=========================使用多單引數查詢===========================");  
3.      List<Employeer> employeers1=getEmployeerList("張三","產品二部");  
4.      for(Employeer employeer1:employeers1){  
5.          System.out.println(employeer1);  
6.      }  

    public static void main(String[] args) {   
         System.out.println("=========================使用多單引數查詢===========================");
         List<Employeer> employeers1=getEmployeerList("張三","產品二部");
         for(Employeer employeer1:employeers1){
             System.out.println(employeer1);
         }

結果：

方法二：

將 resultMap="resultMap" 改成 resultType="Employeer"

[java] view plain copy print?

1. <!--多引數 查詢 返回list 的select 語句，注意 resultMap 的值是指向前面定義好的 -->  
2.      <select id="findEmployeerByNameandDep"  resultType="Employeer">  
3.      select* from `t_employeer` where employeer_name=#{0} and employeer_department=#{1}  
4.      </select>   

<!--多引數 查詢 返回list 的select 語句，注意 resultMap 的值是指向前面定義好的 -->
     <select id="findEmployeerByNameandDep"  resultType="Employeer">
     select* from `t_employeer` where employeer_name=#{0} and employeer_department=#{1}
     </select> 

方法三：Map封裝多引數
EmployeerMapper.java中新增
[java] view plain copy print?

1. /** 
2.  * 多引數查詢，注意要和Employeer.xml的方法名對應 
3.  */  
4. public List<Employeer> findEmployeerByNameandDep1(Map<String,String> map);  

	/**
	 * 多引數查詢，注意要和Employeer.xml的方法名對應
	 */
	public List<Employeer> findEmployeerByNameandDep1(Map<String,String> map);

Employeer.xml中新增： [html] view plain copy print?

1. <!--多引數 查詢 返回list 的select 語句，注意 resultMap 的值是指向前面定義好的,注意key1和key2為傳入的map的鍵值 -->  
2. <select id="findEmployeerByNameandDep1" parameterType="map" resultType="Employeer">  
3. select* from `t_employeer` where employeer_name=#{key1} and employeer_department=#{key2}  
4. </select>   

     <!--多引數 查詢 返回list 的select 語句，注意 resultMap 的值是指向前面定義好的,注意key1和key2為傳入的map的鍵值 -->
     <select id="findEmployeerByNameandDep1" parameterType="map" resultType="Employeer">
     select* from `t_employeer` where employeer_name=#{key1} and employeer_department=#{key2}
     </select> 

其中map是mybatis自己配置好的直接使用就行。map中key的名字是那個就在#{}使用那個。

測試使用：

[java] view plain copy print?

1. /** 
2.  * 多引數查詢列表，使用map 
3.  */  
4. public static List<Employeer> getEmployeerList(Map<String, String> map){  
5.     SqlSession session = null;  
6.      List<Employeer> employeers=null;  
7.     try {  
8.         session = sqlSessionFactory.openSession();   
9.         EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);  
10.          employeers = employeerMapper.findEmployeerByNameandDep1(map);  
11.            session.commit() ;         
12.     } finally {  
13.         session.close();  
14.     }  
15.     return employeers;  
16.    }  

	/**
	 * 多引數查詢列表，使用map
	 */
	public static List<Employeer> getEmployeerList(Map<String, String> map){
		SqlSession session = null;
		 List<Employeer> employeers=null;
		try {
			session = sqlSessionFactory.openSession(); 
			EmployeerMapper employeerMapper=session.getMapper(EmployeerMapper.class);
			 employeers = employeerMapper.findEmployeerByNameandDep1(map);
            session.commit() ;  		
		} finally {
			session.close();
		}
		return employeers;
   
    }

[java] view plain copy print?

1. System.out.println("=========================使用多單引數map方式查詢===========================");  
2. Map<String, String> map = new HashMap<String, String>();   
3. map.put("key1", "明明");   
4. map.put("key2", "財會部");  
5. List<Employeer> employeers2=getEmployeerList(map);  
6. for(Employeer employeer2:employeers2){  
7.           System.out.println(employeer2);  
8.       }  

		 System.out.println("=========================使用多單引數map方式查詢===========================");
		 Map<String, String> map = new HashMap<String, String>(); 
		 map.put("key1", "明明"); 
		 map.put("key2", "財會部");
		 List<Employeer> employeers2=getEmployeerList(map);
		 for(Employeer employeer2:employeers2){
             System.out.println(employeer2);
         }

一定要注意key:

結果：